fix: missing freeing and type (in CIF prepare)

- Feat: finish FFI CIF prepare

.clangd

@@ -0,0 +1,4 @@
+Style:
+  AngledHeaders: [".*"]
+  QuotedHeaders: []
+

.gdbinit

@@ -5,6 +5,7 @@ skip is
 skip -rfunction fzl_mk*
 skip -rfunction fzl_free*
 skip -rfunction fzl_symt*
+skip -rfunction fzl_linked*
 skip add_const
 skip push_op
 skip push_word

.gitignore

@@ -3,15 +3,18 @@
 # Dirs
 !/docs
 !/exl
+!/benchmarks
 !/include
+!/scripts
 !/src
+!/tests
 
 # Files
 !/.clang-format
+!/.clangd
 !/.gdbinit
 !/.gitignore
 !/CMakeLists.txt
 !/Makefile
 !/README.md
 !/README.ru.md
-

CMakeLists.txt

@@ -8,135 +8,221 @@ add_compile_options(-Wall -Wextra -Werror=implicit-function-declaration)
 if (CMAKE_BUILD_TYPE STREQUAL "Debug")
 	add_compile_options(-fsanitize=address,undefined -g)
 	add_link_options(-fsanitize=address,undefined)
+	set(FZL_TESTS TRUE)
 endif()
 
 include_directories(include)
+include(FetchContent)
+
+# --- libffi ---
+
+set(PREV_SUPPRESS_DEV ${CMAKE_SUPPRESS_DEVELOPER_WARNINGS})
+set(CMAKE_SUPPRESS_DEVELOPER_WARNINGS TRUE CACHE INTERNAL "")
+
+FetchContent_Declare(ffi
+	GIT_REPOSITORY "https://git.samsonium.dev/samsonium/libffi.git"
+	GIT_TAG "main"
+)
+FetchContent_MakeAvailable(ffi)
+
+set(CMAKE_SUPPRESS_DEVELOPER_WARNINGS ${PREV_SUPPRESS_DEV} CACHE INTERNAL "")
+
+# --------------
 
 # Compiler
+if (NOT FZL_SKIP_C)
 	add_executable(fzc
-	src/compiler/fzl_token.c
-	src/compiler/fzl_reader.c
-	src/compiler/fzl_parser.c
-	src/compiler/fzl_debug.c
-	src/compiler/fzl_walker.c
-	src/compiler/fzl_writer.c
 		src/compiler/utils/fzl_const_pool.c
 		src/compiler/utils/fzl_symtable.c
 		src/compiler/utils/fzl_linked.c
 		src/compiler/utils/fzl_options.c
 		src/compiler/utils/fzl_ctable.c
+		src/compiler/analyzer/utility.c
+		src/compiler/analyzer/context.c
+		src/compiler/analyzer/an_assign.c
+		src/compiler/analyzer/an_binmath.c
+		src/compiler/analyzer/an_block.c
+		src/compiler/analyzer/an_break.c
+		src/compiler/analyzer/an_call.c
+		src/compiler/analyzer/an_class.c
+		src/compiler/analyzer/an_common.c
+		src/compiler/analyzer/an_condition.c
+		src/compiler/analyzer/an_conditional.c
+		src/compiler/analyzer/an_construct.c
+		src/compiler/analyzer/an_declaration.c
+		src/compiler/analyzer/an_extern.c
+		src/compiler/analyzer/an_externfn.c
+		src/compiler/analyzer/an_field.c
+		src/compiler/analyzer/an_function.c
+		src/compiler/analyzer/an_identifier.c
+		src/compiler/analyzer/an_loop.c
+		src/compiler/analyzer/an_ref.c
+		src/compiler/analyzer/an_return.c
+		src/compiler/analyzer/an_strfmt.c
+		src/compiler/analyzer/an_struct.c
+		src/compiler/analyzer/an_typedef.c
+		src/compiler/analyzer/an_unarycond.c
+		src/compiler/analyzer/an_unarymath.c
+		src/compiler/generator/context.c
+		src/compiler/generator/op.c
+		src/compiler/generator/utility.c
+		src/compiler/generator/gen_alias.c
+		src/compiler/generator/gen_assign.c
+		src/compiler/generator/gen_block.c
+		src/compiler/generator/gen_break.c
+		src/compiler/generator/gen_call.c
+		src/compiler/generator/gen_class.c
+		src/compiler/generator/gen_common.c
+		src/compiler/generator/gen_compare.c
+		src/compiler/generator/gen_condition.c
+		src/compiler/generator/gen_construct.c
+		src/compiler/generator/gen_declaration.c
+		src/compiler/generator/gen_extern.c
+		src/compiler/generator/gen_externfn.c
+		src/compiler/generator/gen_field.c
+		src/compiler/generator/gen_fmtstr.c
+		src/compiler/generator/gen_fn.c
+		src/compiler/generator/gen_handle.c
+		src/compiler/generator/gen_identifier.c
+		src/compiler/generator/gen_literal.c
+		src/compiler/generator/gen_logical.c
+		src/compiler/generator/gen_loop.c
+		src/compiler/generator/gen_math.c
+		src/compiler/generator/gen_reference.c
+		src/compiler/generator/gen_return.c
+		src/compiler/generator/gen_struct.c
+		src/compiler/generator/gen_typedef.c
+		src/compiler/generator/gen_unary_logical.c
+		src/compiler/generator/gen_unary_math.c
+		src/compiler/parser/utility.c
+		src/compiler/parser/pa_and.c
+		src/compiler/parser/pa_assignment.c
+		src/compiler/parser/pa_block.c
+		src/compiler/parser/pa_break.c
+		src/compiler/parser/pa_class.c
+		src/compiler/parser/pa_cond.c
+		src/compiler/parser/pa_expression.c
+		src/compiler/parser/pa_extern.c
+		src/compiler/parser/pa_externfn.c
+		src/compiler/parser/pa_factor.c
+		src/compiler/parser/pa_for.c
+		src/compiler/parser/pa_function.c
+		src/compiler/parser/pa_if.c
+		src/compiler/parser/pa_loop.c
+		src/compiler/parser/pa_new.c
+		src/compiler/parser/pa_or.c
+		src/compiler/parser/pa_postfix.c
+		src/compiler/parser/pa_power.c
+		src/compiler/parser/pa_primary.c
+		src/compiler/parser/pa_program.c
+		src/compiler/parser/pa_ref.c
+		src/compiler/parser/pa_return.c
+		src/compiler/parser/pa_statement.c
+		src/compiler/parser/pa_struct.c
+		src/compiler/parser/pa_term.c
+		src/compiler/parser/pa_typedef.c
+		src/compiler/parser/pa_unary.c
+		src/compiler/parser/pa_while.c
+		src/compiler/reader/rd_fmtstr.c
+		src/compiler/reader/rd_name.c
+		src/compiler/reader/rd_number.c
+		src/compiler/reader/rd_string_literal.c
+		src/compiler/reader/utility.c
+		src/compiler/writer/wr_consts.c
+		src/compiler/writer/wr_extern_fns.c
+		src/compiler/writer/wr_extern_libs.c
+		src/compiler/writer/wr_extern_types.c
+		src/compiler/writer/wr_ops.c
+		src/compiler/fzl_analyzer.c
+		src/compiler/fzl_debug.c
+		src/compiler/fzl_gen.c
+		src/compiler/fzl_parser.c
+		src/compiler/fzl_reader.c
+		src/compiler/fzl_token.c
+		src/compiler/fzl_writer.c
 		src/compiler/main.c)
+endif ()
 
 # Virtual machine
+if (NOT FZL_SKIP_VM)
 	add_executable(fz
+		src/vm/handlers/group_and_or.c
+		src/vm/handlers/group_cmp.c
+		src/vm/handlers/group_ctx.c
+		src/vm/handlers/group_flow.c
+		src/vm/handlers/group_fn.c
+		src/vm/handlers/group_math.c
+		src/vm/handlers/group_not.c
+		src/vm/handlers/group_obj.c
+		src/vm/handlers/group_objcmp.c
+		src/vm/handlers/group_stack.c
+		src/vm/handlers/group_str.c
+		src/vm/handlers/group_strcmp.c
+		src/vm/handlers/master.c
+		src/vm/reader/utility.c
+		src/vm/reader/vm_rd_consts.c
+		src/vm/reader/vm_rd_extern_fns.c
+		src/vm/reader/vm_rd_extern_libs.c
+		src/vm/reader/vm_rd_extern_types.c
+		src/vm/reader/vm_rd_header.c
+		src/vm/reader/vm_rd_ops.c
+		src/vm/reader/vm_rd_sections_sz.c
 		src/vm/fzl_vm.c
 		src/vm/fzl_vm_env.c
+		src/vm/fzl_vm_extern.c
+		src/vm/fzl_vm_reader.c
 		src/vm/fzl_vm_debug.c
 		src/vm/main.c)
 
+	target_link_libraries(fz PRIVATE ffi_static dl)
+endif ()
+
 #
-# ========== Compilation tests ==========
+# ========== Installtion ===========
 #
 
+if (NOT FZL_SKIP_C)
+	install (TARGETS fzc RUNTIME DESTINATION bin)
+endif ()
+
+if (NOT FZL_SKIP_VM)
+	install (TARGETS fz RUNTIME DESTINATION bin)
+endif ()
+
+#
+# ========== Tests ==========
+#
+
+if (FZL_TESTS)
 	enable_testing()
 
-add_test(
+	file(GLOB TEST_LIBS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" "tests/libs/*.c")
-	NAME compile_hw
+	foreach (TEST_LIB IN LISTS TEST_LIBS)
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/hw.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/hw.fzs"
+		get_filename_component(LIB_NAME "${TEST_LIB}" NAME_WE)
-)
+		add_library("${LIB_NAME}" ${TEST_LIB})
-add_test(
+	endforeach ()
-	NAME compile_print_empty
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/print_empty.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/print_empty.fzs"
-)
-add_test(
-	NAME compile_problematic_hw
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/problematic_hw.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/problematic_hw.fzs"
-)
-add_test(
-	NAME compile_base_math
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/base_math.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/base_math.fzs"
-)
-add_test(
-	NAME compile_variables
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/variables.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/variables.fzs"
-)
-add_test(
-	NAME compile_conditions
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/conditions.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/conditions.fzs"
-)
-add_test(
-	NAME compile_fn
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/fn.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/fn.fzs"
-)
-add_test(
-	NAME compile_comment
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/comment.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/comment.fzs"
-)
-add_test(
-	NAME compile_class
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/class.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/class.fzs"
-)
-add_test(
-	NAME compile_raii
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/raii.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/raii.fzs"
-)
-add_test(
-	NAME compile_borrow
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/borrow.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/borrow.fzs"
-)
-add_test(
-	NAME compile_hard_1
-	COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/hard-1.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/exl/hard-1.fzs"
-)
 
-set_tests_properties(compile_problematic_hw PROPERTIES WILL_FAIL TRUE)
+	file(GLOB TEST_PROGS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" "tests/programs/*.fzs")
-
+	foreach (TEST_FILE IN LISTS TEST_PROGS)
-#
+		get_filename_component(TEST_NAME "${TEST_FILE}" NAME_WE)
-# ========== Runtime tests ==========
-#
 		
 		add_test(
-	NAME runtime_hw
+			NAME "progs_compile_${TEST_NAME}"
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/hw.fzb"
+			COMMAND fzc -o "${CMAKE_CURRENT_BINARY_DIR}/p_${TEST_NAME}.fzb" "${CMAKE_CURRENT_SOURCE_DIR}/${TEST_FILE}"
 		)
 		add_test(
-	NAME runtime_print_empty
+			NAME "progs_runtime_${TEST_NAME}"
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/print_empty.fzb"
+			COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/p_${TEST_NAME}.fzb"
-)
-add_test(
-	NAME runtime_base_math
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/base_math.fzb"
-)
-add_test(
-	NAME runtime_variables
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/variables.fzb"
-)
-add_test(
-	NAME runtime_conditions
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/conditions.fzb"
-)
-add_test(
-	NAME runtime_fn
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/fn.fzb"
-)
-add_test(
-	NAME runtime_comment
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/comment.fzb"
-)
-add_test(
-	NAME runtime_class
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/class.fzb"
-)
-add_test(
-	NAME runtime_raii
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/raii.fzb"
-)
-add_test(
-	NAME runtime_borrow
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/borrow.fzb"
-)
-add_test(
-	NAME runtime_hard_1
-	COMMAND fz "${CMAKE_CURRENT_BINARY_DIR}/hard-1.fzb"
 		)
 
+		if (TEST_NAME MATCHES "neg_")
+			set_tests_properties("progs_compile_${TEST_NAME}" PROPERTIES WILL_FAIL TRUE)
+			set_tests_properties("progs_runtime_${TEST_NAME}" PROPERTIES WILL_FAIL TRUE)
+		endif()
+
+		if (TEST_NAME MATCHES "negr_")
+			set_tests_properties("progs_runtime_${TEST_NAME}" PROPERTIES WILL_FAIL TRUE)
+		endif ()
+	endforeach ()
+endif ()
+

Makefile

@@ -1,17 +1,58 @@
-.PHONY: configure build debug-c debug-vm test
+.PHONY: build debug-c debug-vm test bench
 
-configure:
+BENCH_FILE ?= benchmarks/loop.fzs
+RUNS ?= 7
+WARMUP ?= 2
+MAX_ITER ?= 2000000
+
+current_time = python3 -c "import time; print(time.time())"
+
+build-debug:
 	cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
-
-build: configure
 	cmake --build build
 
-debug-c: build
+build:
-	gdb --args ./build/fzc ${FILE}
+	cmake -S . -B build -DCMAKE_BUILD_TYPE=Release $(COMPARING)
+	cmake --build build $(COMPARING)
 
-debug-vm: build
+install:
+	cmake --install build
+
+debug-c: build-debug
+	gdb --args ./build/fzc -v ${FILE}
+
+debug-vm: build-debug
 	gdb --args ./build/fz ${FILE}
 
+test-debug: build-debug
+	ctest --output-on-failure --test-dir build
+
 test: build
 	ctest --output-on-failure --test-dir build
 
+bench: COMPARING=&>/dev/null
+bench: build
+	@./build/fzc -o build/benchmark.fzb $(BENCH_FILE)
+	@python3 scripts/benchmark.py --runs $(RUNS) --warmup $(WARMUP) \
+		--max-iter $(MAX_ITER) --vm ./build/fz --program build/benchmark.fzb
+
+compare: COMPARING=&>/dev/null
+compare: build
+	@echo "=== Million sums benchmark ==="
+
+	@./build/fzc -o build/bench.fzb $(BENCH_FILE) 1>/dev/null 2>/dev/null
+
+	@ST=$$($(current_time)); \
+	./build/fz --allow-infinite build/bench.fzb 1>/dev/null 2>/dev/null; \
+	ET=$$($(current_time)); \
+	python3 -c "delta = ($$ET - $$ST) * 1000; print(f'FZLang : {delta:.5f} ms')"
+
+	@ST=$$($(current_time)); \
+	./benchmarks/loop-c 1>/dev/null 2>/dev/null; \
+	ET=$$($(current_time)); \
+	python3 -c "delta = ($$ET - $$ST) * 1000; print(f'C      : {delta:.5f} ms')"
+
+	@ST=$$($(current_time)); \
+	python3 ./benchmarks/loop.py 1>/dev/null 2>/dev/null; \
+	ET=$$($(current_time)); \
+	python3 -c "delta = ($$ET - $$ST) * 1000; print(f'CPython: {delta:.5f} ms')"

README.md

@@ -27,7 +27,7 @@ Working examples of code can be found in `exl/` directory.
 ## Building
 
 1. Clone the repository: `git clone https://git.samsonium.dev/samsonium/fz-lang.git`
-2. Build: `make build`
+2. Build: `make build-release`
 
 After this, a "build" directory will appear in the project root. It will contain two executable files:
 

README.ru.md

@@ -28,11 +28,7 @@
 
 1. Склонировать проект: `git clone https://git.samsonium.dev/samsonium/fz-lang.git`
 2. Собрать проект: `make build`
-
+3. Установить проект: `sudo make install`
-После этого в корне появится директория **"build"**. В ней будут лежать два скомпилированных бинарных файла:
-
-- `fzc` - компилятор
-- `fz` - виртуальная машина
 
 Оба бинарных файла предоставляют справку по использованию при запуске с флагом `--help` (или `-h`).
 
@@ -51,3 +47,20 @@ $ make debug-c FILE=exl/hw.fzs
 
 Для проверки новых фич, нужно использовать make-таргет `test`, а тесты писать в `CMakeLists.txt`.
 
+### Бенчмаркинг
+
+`make bench` собирает Release-версию, компилирует `benchmarks/loop.fzs` один раз и
+измеряет время запуска программы в виртуальной машине. По умолчанию выполняются
+2 прогрева и 7 замеров; выводятся медиана, среднее, минимум и максимум. Компиляция
+исходника в измерения не входит.
+
+Параметры можно переопределить:
+
+```shell
+make bench RUNS=15 WARMUP=3
+make bench BENCH_FILE=path/to/program.fzs MAX_ITER=2000000
+```
+
+Измеряется полное время запуска процесса `fz` (включая загрузку программы), а не
+только цикл интерпретации. Для сопоставимых результатов запускайте бенчмарк на
+одной машине и не меняйте нагрузку между прогонами.

benchmarks/loop.fzs

@@ -0,0 +1,9 @@
+// Integer loop workload for measuring VM execution without I/O.
+uint i = 0;
+uint sum = 0;
+
+for (i = 0; i < 1000000; i = i + 1)
+  sum = sum + i;
+
+printline(sum);
+

benchmarks/loop.py

@@ -0,0 +1,4 @@
+s = 0
+for i in range(1_000_000):
+    s += i
+print(s)

exl/00_variables.fzs

@@ -0,0 +1,32 @@
+// There are two ways to work with variables
+// 1. Declare variable:
+str someString = "world, hello!";
+
+// 2. Change variable value:
+someString = "hello, world!";
+
+// Variables help you store values to use it later
+int a = 2;
+int b = a + a * a;
+int c = a * b;
+
+printline("Now we got 12:");
+printline(c);
+
+// Also, there are many different variable types to help your program
+//  work with many things:
+int signedInteger;
+uint unsignedInteger;
+str string;
+bool boolean;
+
+i8  integer1; // 8-byte int
+i16 integer2; // 16-byte int
+i32 integer3; // 32-byte int
+i64 integer4; // 64-byte int
+
+u8  integer5; // unsigned 8-byte integer
+u16 integer6; // unsigned 16-byte integer
+u32 integer7; // unsigned 32-byte integer
+u64 integer8; // unsigned 64-byte integer
+

exl/01_conditions.fzs

@@ -0,0 +1,30 @@
+// When you need to check some value
+//  a conditional statement might help you
+
+int valueToCheck = 2 + 2;
+if (valueToCheck == 4)
+{
+  printline("Yay! 2 + 2 = 4");
+}
+
+// Conditional statement uses condition in parenthesis
+//  after `if` keyword and executes command(s) after
+//  if condition turns out to be true
+
+// Otherwise, to execute block when condition turns
+//  out to be false, you can use `else` keyword:
+
+int age = 30;
+
+if (age <= 20)
+  printline("You're too young");
+else
+{
+  age = 20;
+  printline("You look too young!");
+}
+
+// NOTE: If you need to execute only one statement
+//  inside `if` or `else` block, then the curly
+//  braces can be omitted.
+

exl/02_functions.fzs

@@ -0,0 +1,30 @@
+// If you have some code section which is
+//  duplicated in program several times
+//  then it means your program needs some
+//  functions!
+
+fn doSomeWork()
+{
+  printline("Some work");
+}
+
+// If the function makes some kind of
+//  calculations then you should specify
+//  the result type
+
+fn sum(int a, int b) int
+{
+  return a + b;
+}
+
+// The `return` keyword can be used to
+//  actually return the value from the
+//  function. Also, you can specify list
+//  of arguments that you will use inside
+//  the function
+
+int first = 5;
+int second = 6;
+int result = sum(first, second);
+printline(result);
+

exl/borrow.fzs

@@ -1,46 +0,0 @@
-class A
-{
-  uint some;
-}
-
-fn doSome(A a) A
-{
-  // NOTE: section below won't change `a.some` value
-
-  if (a.some < 1)
-  {
-    a.some = 1;
-    return a;
-  }
-
-  return a;
-}
-
-fn doSomeNew() A
-{
-  if (1 == 1)
-  {
-    return new A;
-  }
-}
-
-A a = new A;
-a.some = 0;
-if (a.some != 0)
-{
-  printline("Test failed (first a.some != 0)");
-  exit(1);
-}
-else printline(a);
-
-a = doSome(a);
-if (a.some != 1)
-{
-  printline("Test failed (2nd a.some != 1)");
-  exit(1);
-}
-else printline(a);
-
-A b = doSomeNew();
-printline(b);
-

exl/class.fzs

@@ -1,36 +0,0 @@
-class Point
-{
-  int x;
-  int y;
-
-  // Move point by [dx,dy]
-  fn move(int dx, int dy) {
-    this.x = this.x + dx;
-    this.y = this.y + dy;
-  }
-}
-
-Point obj = new Point;
-obj.x = 1;
-obj.y = 2;
-
-printline("Current X,Y:");
-printline(obj.x);
-printline(obj.y);
-
-// NOTE: WHY THE FUCK THIS FUCKING COMPILER REQUIRES ';' AFTER '='?!
-//      |
-//      v
-obj.move(9, 8);
-printline("X,Y after move:");
-printline(obj.x);
-printline(obj.y);
-
-if (obj.x == 10 && obj.y == 10)
-  printline("Test passed");
-else
-{
-  printline("Test failed");
-  exit(1);
-}
-

exl/comment.fzs

@@ -1,3 +0,0 @@
-// I'm a comment
-printline("Comment is skipped");;;;;
-

exl/conditions.fzs

@@ -1,20 +0,0 @@
-bool flag = true;
-
-if (!flag)
-{
-  printline("buhhh, flag is not true");
-  exit(1);
-}
-else if (2 + 2 >= 4)
-{
-  printline ("two plus two is four");
-}
-else {
-  printline("gotcha");
-  exit(1);
-}
-
-{
-  printline("block after");
-}
-

exl/fn.fzs

@@ -1,32 +0,0 @@
-fn fib(int n) int
-{
-  if (n <= 1)
-    return n;
-
-  return fib(n - 1) + fib(n - 2);
-}
-
-fn sum(uint a, uint b) uint
-{
-  return a + b;
-}
-
-printline("Test #1: fibonacci");
-int result = fib(7);
-if (result == 13)
-  printline("Recurse test passed");
-else
-{
-  printline("Recurse test failed");
-  exit(1);
-}
-
-printline("Test #2: sum");
-if (sum(2, 2) == 4)
-  printline("Sum test passed");
-else
-{
-  printline("Sum test failed");
-  exit(1);
-}
-

exl/hw.fzs

@@ -1,2 +0,0 @@
-printline('hello, world');
-

exl/linking.fzs

@@ -0,0 +1,41 @@
+extern "libglfw" {
+
+  // Opaque types
+  type GLFWwindow  handle;
+  type GLFWmonitor handle;
+
+  // Struct definition
+  type GLFWvidmode struct {
+    int width;
+    int height;
+    int redBits;
+    int greenBits;
+    int blueBits;
+    int refreshRate;
+  };
+
+  /// GLFWvidmode*
+  type GLFWvidmodeRef ref GLFWvidmode;
+
+  /// Create window with specified [width], [height] and [title]
+  fn glfw_mkWindow(
+    int width,
+    int height,
+    str title,
+    GLFWmonitor mon,
+    GLFWwindow shr
+  ) GLFWwindow = "glfwCreateWindow";
+
+  /// Get videomode from monitor [mon]
+  fn glfw_getVideoMode(
+    GLFWmonitor mon
+  ) GLFWvidmodeRef = "glfwGetVideoMode";
+
+  /// Get framebuffer [width] and [height]
+  fn glfw_getFrameBufferSize(
+    GLFWwindow win,
+    out int width,
+    out int height
+  ) = "glfwGetFramebufferSize";
+}
+

exl/print_empty.fzs

@@ -1 +0,0 @@
-printline("");

exl/problematic_hw.fzs

@@ -1 +0,0 @@
-printline("hello);

exl/raii.fzs

@@ -1,46 +0,0 @@
-class Animal
-{
-  str type;
-  str name;
-  int age;
-
-  fn copy() Animal
-  {
-    Animal cp = new Animal;
-    cp.type = this.type;
-    cp.name = this.name;
-    cp.age = this.age;
-
-    return cp;
-  }
-}
-
-Animal a = new Animal;
-a.type = "Cow";
-a.name = "Buryatka";
-a.age = 5;
-
-Animal b = a.copy();
-b.name = "Gavryusha";
-b.age = 10;
-
-printline(a);
-printline(b);
-
-printline("Types are same:");
-printline(a.type == b.type);
-
-printline("Names are NOT the same");
-printline(a.name != b.name);
-
-printline("1st age less than 2nd");
-printline(a.age < b.age);
-
-if (a.type == b.type && a.name != b.name && a.age < b.age)
-  printline("Test passed");
-else
-{
-  printline("Test failed");
-  exit(1);
-}
-

include/common/fzl_extern.h

@@ -0,0 +1,86 @@
+#ifndef FZL_EXTERN_H
+#define FZL_EXTERN_H
+
+#include <common/fzl_types.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+typedef enum
+{
+  FZL_EXTERN_KIND_HANDLE,
+  FZL_EXTERN_KIND_STRUCT,
+  FZL_EXTERN_KIND_REF,
+  FZL_EXTERN_KIND_ALIAS,
+} fzl_extern_kind_t;
+
+// Type reference descriptor
+typedef struct
+{
+  bool is_primitive;
+  union
+  {
+    fzl_type_t primitive;
+    size_t type_slot;
+  };
+} fzl_extern_type_ref_t;
+
+// Structure field descriptor
+typedef struct
+{
+  char *name;
+  fzl_extern_type_ref_t type;
+} fzl_extern_struct_field_t;
+
+// Type descriptor
+typedef struct
+{
+  size_t lib_slot;
+  char *name;
+  fzl_extern_kind_t kind;
+
+  union
+  {
+    // Structure
+    struct
+    {
+      fzl_extern_struct_field_t *fields;
+      size_t fields_count;
+    } structure;
+
+    // Pointer (ref)
+    fzl_extern_type_ref_t ref_target;
+
+    // Alias
+    fzl_extern_type_ref_t alias_target;
+  };
+} fzl_extern_type_t;
+
+// Function argument descriptor
+typedef struct
+{
+  char *name;
+  fzl_extern_type_ref_t type;
+  bool is_out;
+} fzl_extern_arg_t;
+
+// Function descriptor
+typedef struct
+{
+  size_t lib_slot;
+  char *symbol_name;
+  char *used_name;
+
+  bool has_return;
+  fzl_extern_type_ref_t ret_type;
+
+  fzl_extern_arg_t *args;
+  size_t args_count;
+} fzl_extern_fn_t;
+
+// Library descriptor
+typedef struct
+{
+  char *name;
+} fzl_extern_lib_t;
+
+#endif // FZL_EXTERN_H

include/common/fzl_opcodes.h

@@ -14,12 +14,15 @@ typedef enum
   FZL_OPCODE_STORE       = 0xF10003, // Push variable to environment table
   FZL_OPCODE_LOOKUP_ENV  = 0xF10004, // Lookup name in environment table
   FZL_OPCODE_WRITE       = 0xF10005, // Wirte into variable
+  FZL_OPCODE_LOAD_LOCAL  = 0xF10006, // Load local variable
+  FZL_OPCODE_STORE_LOCAL = 0xF10007, // Store local variable
 
   FZL_OPCODE_JMP = 0xF20001, // Jump to specified IP address
   FZL_OPCODE_JZ  = 0xF20002, // Jump if top value in dstack is zero
 
   FZL_OPCODE_CALL        = 0xF30001, // Call function
   FZL_OPCODE_RET         = 0xF30002, // Return from function
+  FZL_OPCODE_CALL_EXTERN = 0xF30003, // Call external function
 
   FZL_OPCODE_ALLOC_OBJECT  = 0xFA0001, // Allocate N slots
   FZL_OPCODE_GET_FIELD     = 0xFA0002, // Get field N of an object at dstack
@@ -35,6 +38,8 @@ typedef enum
   FZL_OPCODE_MOD = 0xA00006, // Get module of two numbers in dstack
   FZL_OPCODE_NEG = 0xA00007, // Negotiate number in dstack
 
+  FZL_OPCODE_BUILD_STR = 0xA10001, // Build a string from N values in dstack
+
   FZL_OPCODE_CMP_EQ   = 0xB00001, // Equal
   FZL_OPCODE_CMP_NEQ  = 0xB00002, // Not equal
   FZL_OPCODE_CMP_LT   = 0xB00003, // Less than

include/common/fzl_types.h

@@ -6,6 +6,10 @@ typedef enum
   FZL_TYPE_NULL,
   FZL_TYPE_OBJECT,
 
+  FZL_TYPE_EXTERN_FN,
+  FZL_TYPE_HANDLE,
+  FZL_TYPE_STRUCT,
+
   FZL_TYPE_STRING,
   FZL_TYPE_CHAR,
   FZL_TYPE_BOOL,

include/compiler/fzl_analyzer.h

@@ -0,0 +1,79 @@
+#ifndef FZL_ANALYZER_H
+#define FZL_ANALYZER_H
+
+#include <common/fzl_types.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+// Analyzing context type
+typedef enum
+{
+  FZL_AN_CTX_TYPE_UNNECESSARY, // default type
+  FZL_AN_CTX_TYPE_FUNCTION,    // when analyzing function
+  FZL_AN_CTX_TYPE_LOOP,        // when analyzing loop
+  FZL_AN_CTX_TYPE_CLASS,       // when analyzing class
+} fzl_an_ctx_type_t;
+
+// Inner node analyzing result descriptor
+typedef struct
+{
+  bool error;
+
+  fzl_type_t type;
+  char *classname;
+} fzl_an_res_t;
+
+// Current node context descriptor
+typedef struct fzl_an_ctx
+{
+  struct fzl_an_ctx *parent;
+
+  fzl_an_ctx_type_t type;
+  fzl_symtable_t *symbols;
+  size_t symbols_level;
+
+  union
+  {
+    fzl_node_t *fn;
+    char *classname;
+  };
+} fzl_an_ctx_t;
+
+// Analyzer descriptor
+typedef struct
+{
+  char *warnings[256];
+  size_t warnings_top;
+
+  char *errors[256];
+  size_t errors_top;
+
+  fzl_symtable_t *symbols[256];
+  size_t symbols_top;
+
+  char *alloc_names[256];
+  size_t alloc_names_top;
+
+  fzl_node_t *root;
+  fzl_an_ctx_t *ctx;
+} fzl_analyzer_t;
+
+// Allocate analyzer
+fzl_analyzer_t *fzl_mkanalyzer(fzl_node_t *node);
+
+// Push error to errors list
+bool an_push_error(fzl_analyzer_t *analyzer, fzl_token_t *tok, char *error);
+
+// Push warning to warnings list
+bool an_push_warning(fzl_analyzer_t *analyzer, fzl_token_t *tok, char *warning);
+
+// Analyze AST
+void fzl_analyze(fzl_analyzer_t *analyzer);
+
+// Free analyzer
+void fzl_freeanalyzer(fzl_analyzer_t *analyzer);
+
+#endif // FZL_ANALYZER_H

include/compiler/fzl_gen.h

@@ -0,0 +1,77 @@
+#ifndef FZL_GENERATOR_H
+#define FZL_GENERATOR_H
+
+#include <common/fzl_extern.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/utils/fzl_const_pool.h>
+#include <compiler/utils/fzl_ctable.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+// Generator context type
+typedef enum
+{
+  FZL_GEN_CTX_TYPE_UNECCESSARY,
+  FZL_GEN_CTX_TYPE_FUNCTION,
+  FZL_GEN_CTX_TYPE_CLASS,
+  FZL_GEN_CTX_TYPE_LOOP
+} fzl_gen_ctx_type_t;
+
+// Generator context descriptor
+typedef struct fzl_gen_ctx
+{
+  fzl_gen_ctx_type_t type;
+  struct fzl_gen_ctx *parent;
+
+  size_t level;
+
+  union
+  {
+    fzl_node_t *function;
+
+    struct
+    {
+      size_t breaks[256];
+      size_t breaks_count;
+    } loop;
+  };
+} fzl_gen_ctx_t;
+
+// Generator descriptor
+typedef struct
+{
+  fzl_node_t *root;
+  fzl_const_hash_pool_t *consts;
+  fzl_gen_ctx_t *ctx;
+
+  size_t *ops;
+  size_t ops_count;
+  size_t ops_remainder;
+
+  fzl_symtable_t *syms[256];
+  size_t syms_top;
+
+  fzl_ctable_t *classes[64];
+  size_t classes_count;
+
+  fzl_extern_lib_t extern_libs[64];
+  size_t extern_libs_count;
+
+  fzl_extern_type_t extern_types[256];
+  size_t extern_types_count;
+
+  fzl_extern_fn_t extern_fns[256];
+  size_t extern_fns_count;
+} fzl_gen_t;
+
+// Allocate new generator
+fzl_gen_t *fzl_mkgen(fzl_node_t *root);
+
+// Run program generation
+bool fzl_gen_run(fzl_gen_t *gen);
+
+// Free generator
+void fzl_freegen(fzl_gen_t *gen);
+
+#endif // FZL_GENERATOR_H

include/compiler/fzl_parser.h

@@ -3,22 +3,40 @@
 
 #include <compiler/fzl_reader.h>
 #include <compiler/fzl_token.h>
+#include <stdbool.h>
 #include <stddef.h>
 
 // AST node type
 typedef enum
 {
+  FZL_NODETYPE_TYPEDEF,
+  FZL_NODETYPE_HANDLE,
+  FZL_NODETYPE_ALIAS,
+  FZL_NODETYPE_STRUCT,
+  FZL_NODETYPE_REFERENCE,
+  FZL_NODETYPE_EXTERN_FN,
+
+  FZL_NODETYPE_EXTERN,
   FZL_NODETYPE_BLOCK,
-  FZL_NODETYPE_CALL,
+
   FZL_NODETYPE_LITERAL,
+  FZL_NODETYPE_FMT_STRING,
+
   FZL_NODETYPE_IDENTIFIER,
+
   FZL_NODETYPE_CONDITIONAL,
+
   FZL_NODETYPE_FUNCTION,
   FZL_NODETYPE_RETURN,
+  FZL_NODETYPE_CALL,
+
   FZL_NODETYPE_CLASS,
   FZL_NODETYPE_FIELD,
   FZL_NODETYPE_CONSTRUCT,
 
+  FZL_NODETYPE_LOOP,
+  FZL_NODETYPE_BREAK,
+
   FZL_NODETYPE_ADD,
   FZL_NODETYPE_SUB,
   FZL_NODETYPE_MUL,
@@ -89,6 +107,7 @@ typedef struct fzl_node
     {
       fzl_token_t *type;
       struct fzl_node *identifier;
+      bool is_out;
     } var;
 
     // Conditional blocks
@@ -140,6 +159,56 @@ typedef struct fzl_node
     {
       struct fzl_node *name;
     } construct;
+
+    // Loop
+    struct
+    {
+      struct fzl_node *init;
+      struct fzl_node *cond;
+      struct fzl_node *step;
+
+      struct fzl_node *body;
+    } loop;
+
+    // Extern library
+    struct
+    {
+      char *libname;
+
+      struct fzl_node **typedefs;
+      size_t typedefs_count;
+
+      struct fzl_node **fns;
+      size_t fns_count;
+    } ext;
+
+    // Type definition
+    struct
+    {
+      char *typename;
+      struct fzl_node *type;
+    } typedefinition;
+
+    // Structure
+    struct
+    {
+      char *original_name;
+
+      struct fzl_node **entries;
+      size_t entries_count;
+    } structure;
+
+    // External function
+    struct
+    {
+      char *name;
+      char *original_name;
+
+      fzl_token_t *type;
+
+      struct fzl_node **args;
+      size_t args_count;
+    } ext_fn;
   };
 } fzl_node_t;
 

include/compiler/fzl_token.h

@@ -8,53 +8,68 @@
 // Token type
 typedef enum
 {
-  FZL_TOKTYPE_CLASS, // class
+  FZL_TOKTYPE_IMPORT,    // `import`
-  FZL_TOKTYPE_NEW,   // new
+  FZL_TOKTYPE_EXTERN,    // `extern`
+  FZL_TOKTYPE_TYPEDEF,   // `type`
+  FZL_TOKTYPE_HANDLE,    // `handle`
+  FZL_TOKTYPE_STRUCT,    // `struct`
+  FZL_TOKTYPE_REFERENCE, // `ref`
+  FZL_TOKTYPE_OUT,       // `out`
 
-  FZL_TOKTYPE_FUNCTION, // fn
+  FZL_TOKTYPE_CLASS, // `class`
-  FZL_TOKTYPE_RETURN,   // return
+  FZL_TOKTYPE_NEW,   // `new`
 
-  FZL_TOKTYPE_IF,   // if
+  FZL_TOKTYPE_FUNCTION, // `fn`
-  FZL_TOKTYPE_ELSE, // else
+  FZL_TOKTYPE_RETURN,   // `return`
+
+  FZL_TOKTYPE_FOR,   // `for`
+  FZL_TOKTYPE_WHILE, // `while`
+  FZL_TOKTYPE_BREAK, // `break`
+
+  FZL_TOKTYPE_IF,   // `if`
+  FZL_TOKTYPE_ELSE, // `else`
 
   FZL_TOKTYPE_NAME, // abc
   FZL_TOKTYPE_TYPE, // i16
 
-  FZL_TOKTYPE_DDASH, // // :D
+  FZL_TOKTYPE_DDASH, // `//` :D
 
-  FZL_TOKTYPE_LPAREN, // (
+  FZL_TOKTYPE_LPAREN, // `(`
-  FZL_TOKTYPE_RPAREN, // )
+  FZL_TOKTYPE_RPAREN, // `)`
-  FZL_TOKTYPE_LBRACE, // {
+  FZL_TOKTYPE_LBRACE, // `{`
-  FZL_TOKTYPE_RBRACE, // }
+  FZL_TOKTYPE_RBRACE, // `}`
 
-  FZL_TOKTYPE_COMMA,     // ,
+  FZL_TOKTYPE_COMMA,     // `,`
-  FZL_TOKTYPE_DOT,       // .
+  FZL_TOKTYPE_DOT,       // `.`
-  FZL_TOKTYPE_SEMICOLON, // ;
+  FZL_TOKTYPE_SEMICOLON, // `;`
 
   FZL_TOKTYPE_STR_LITERAL,  // ""
   FZL_TOKTYPE_NUM_LITERAL,  // 123
   FZL_TOKTYPE_BOOL_LITERAL, // true
   FZL_TOKTYPE_NULL_LITERAL, // null
 
-  FZL_TOKTYPE_DAMPERSAND, // &&
+  FZL_TOKTYPE_STR_FORMAT_START, // `$` before `"`
-  FZL_TOKTYPE_DVBAR,      // ||
+  FZL_TOKTYPE_STR_FORMAT_END,   // end of string formatting sequence
 
-  FZL_TOKTYPE_EQEQ,   // ==
+  FZL_TOKTYPE_DAMPERSAND, // `&&`
-  FZL_TOKTYPE_REQ,    // >=
+  FZL_TOKTYPE_DVBAR,      // `||`
-  FZL_TOKTYPE_LEQ,    // <=
-  FZL_TOKTYPE_NEQ,    // !=
-  FZL_TOKTYPE_LANGLE, // <
-  FZL_TOKTYPE_RANGLE, // >
-  FZL_TOKTYPE_NOT,    // !
 
-  FZL_TOKTYPE_STAR,    // *
+  FZL_TOKTYPE_EQEQ,   // `==`
-  FZL_TOKTYPE_SLASH,   // /
+  FZL_TOKTYPE_REQ,    // `>=`
-  FZL_TOKTYPE_PLUS,    // +
+  FZL_TOKTYPE_LEQ,    // `<=`
-  FZL_TOKTYPE_MINUS,   // -
+  FZL_TOKTYPE_NEQ,    // `!=`
-  FZL_TOKTYPE_CARET,   // ^
+  FZL_TOKTYPE_LANGLE, // `<`
-  FZL_TOKTYPE_PERCENT, // %
+  FZL_TOKTYPE_RANGLE, // `>`
+  FZL_TOKTYPE_NOT,    // `!`
 
-  FZL_TOKTYPE_EQ // =
+  FZL_TOKTYPE_STAR,    // `*`
+  FZL_TOKTYPE_SLASH,   // `/`
+  FZL_TOKTYPE_PLUS,    // `+`
+  FZL_TOKTYPE_MINUS,   // `-`
+  FZL_TOKTYPE_CARET,   // `^`
+  FZL_TOKTYPE_PERCENT, // `%`
+
+  FZL_TOKTYPE_EQ // `=`
 } fzl_toktype_t;
 
 // Token descriptor

include/compiler/fzl_walker.h

@@ -1,76 +0,0 @@
-#ifndef FZL_WALKER_H
-#define FZL_WALKER_H
-
-#include <common/fzl_opcodes.h>
-#include <common/fzl_types.h>
-#include <compiler/fzl_parser.h>
-#include <compiler/utils/fzl_const_pool.h>
-#include <compiler/utils/fzl_ctable.h>
-#include <compiler/utils/fzl_symtable.h>
-#include <stdbool.h>
-#include <stddef.h>
-
-// Type of context
-typedef enum
-{
-  FZL_WALK_CTX_TYPE_GLOBAL,
-  FZL_WALK_CTX_TYPE_FN,
-  FZL_WALK_CTX_TYPE_CLASS,
-  FZL_WALK_CTX_TYPE_ASSIGN
-} fzl_walk_ctx_type_t;
-
-// Internal walk function result
-typedef struct
-{
-  fzl_type_t type;
-
-  char *error_msg;
-  bool error;
-
-  char *classname;
-} fzl_walk_res_t;
-
-// Function context descriptor
-typedef struct fzl_walk_ctx
-{
-  fzl_walk_ctx_type_t type;
-  struct fzl_walk_ctx *parent;
-
-  fzl_node_t *fn;
-  size_t initial_env_lvl;
-} fzl_walk_ctx_t;
-
-// Walker descriptor
-typedef struct
-{
-  fzl_node_t *root;
-  fzl_const_hash_pool_t *consts;
-
-  uint64_t *ops;
-  size_t op_count;
-  size_t op_remainder;
-
-  fzl_symtable_t *syms[64];
-  size_t sym_top;
-
-  fzl_walk_ctx_t *ctx;
-
-  fzl_ctable_t *classes[64];
-  size_t classes_count;
-} fzl_walker_t;
-
-// Allocate new walker
-fzl_walker_t *fzl_mkwalker(fzl_node_t *root);
-
-// Walk throught the entire AST and build:
-// 1. Constants table
-// 2. Operations
-int fzl_walk(fzl_walker_t *walker);
-
-// Get last error message
-char *fzl_walker_geterror();
-
-// Free walker
-void fzl_freewalker(fzl_walker_t *walker);
-
-#endif // FZL_WALKER_H

include/compiler/fzl_writer.h

@@ -1,7 +1,7 @@
 #ifndef FZL_WRITER_H
 #define FZL_WRITER_H
 
-#include <compiler/fzl_walker.h>
+#include <compiler/fzl_gen.h>
 #include <compiler/utils/fzl_const_pool.h>
 
 // File writer descriptor
@@ -14,7 +14,7 @@ typedef struct
 fzl_writer_t *fzl_mkwriter(const char *filepath);
 
 // Write out a file
-int fzl_write(fzl_writer_t *writer, fzl_walker_t *walker);
+int fzl_write(fzl_writer_t *writer, fzl_gen_t *gen);
 
 // Get last writer error message
 char *fzl_writer_geterror();

include/compiler/internals/analyzer.h

@@ -0,0 +1,45 @@
+#ifndef INTERNALS_ANALYZER_H
+#define INTERNALS_ANALYZER_H
+
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <stdbool.h>
+
+extern char an_problem[256];
+
+bool an_is_compatible(fzl_type_t a, fzl_type_t b, char *ac, char *bc);
+char *an_typetostr(fzl_type_t type, char *classname);
+fzl_type_t an_toktotype(fzl_analyzer_t *analyzer, fzl_token_t *tok,
+                        bool *sym_found);
+
+fzl_an_res_t analyze_common(fzl_analyzer_t *analyzer, fzl_node_t *node);
+fzl_an_res_t analyze_call(fzl_analyzer_t *analyzer, fzl_node_t *call_node);
+fzl_an_res_t analyze_identifier(fzl_analyzer_t *analyzer, fzl_node_t *id);
+fzl_an_res_t analyze_conditional(fzl_analyzer_t *analyzer, fzl_node_t *cond);
+fzl_an_res_t analyze_function(fzl_analyzer_t *analyzer, fzl_node_t *fn_node);
+fzl_an_res_t analyze_block(fzl_analyzer_t *analyzer, fzl_node_t *block_node);
+fzl_an_res_t analyze_return(fzl_analyzer_t *analyzer, fzl_node_t *ret_node);
+fzl_an_res_t analyze_class(fzl_analyzer_t *analyzer, fzl_node_t *class_node);
+fzl_an_res_t analyze_field(fzl_analyzer_t *analyzer, fzl_node_t *field);
+fzl_an_res_t analyze_declaration(fzl_analyzer_t *analyzer, fzl_node_t *decl);
+fzl_an_res_t analyze_construct(fzl_analyzer_t *analyzer, fzl_node_t *construct);
+fzl_an_res_t analyze_loop(fzl_analyzer_t *analyzer, fzl_node_t *loop_node);
+fzl_an_res_t analyze_break(fzl_analyzer_t *analyzer, fzl_node_t *break_node);
+fzl_an_res_t analyze_binmath(fzl_analyzer_t *analyzer, fzl_node_t *bin_node);
+fzl_an_res_t analyze_unarymath(fzl_analyzer_t *analyzer, fzl_node_t *unary);
+fzl_an_res_t analyze_condition(fzl_analyzer_t *analyzer, fzl_node_t *cond_node);
+fzl_an_res_t analyze_unarycond(fzl_analyzer_t *analyzer, fzl_node_t *unary);
+fzl_an_res_t analyze_assign(fzl_analyzer_t *analyzer, fzl_node_t *assign_node);
+fzl_an_res_t analyze_strfmt(fzl_analyzer_t *analyzer, fzl_node_t *strfmt_node);
+fzl_an_res_t analyze_typedef(fzl_analyzer_t *analyzer, fzl_node_t *td_node);
+fzl_an_res_t analyze_struct(fzl_analyzer_t *analyzer, fzl_node_t *struct_node);
+fzl_an_res_t analyze_ref(fzl_analyzer_t *analyzer, fzl_node_t *ref_node);
+fzl_an_res_t analyze_externfn(fzl_analyzer_t *analyzer, fzl_node_t *externfn);
+fzl_an_res_t analyze_extern(fzl_analyzer_t *analyzer, fzl_node_t *extern_node);
+
+fzl_an_ctx_t *an_nest_ctx(fzl_analyzer_t *analyzer, fzl_an_ctx_type_t type);
+fzl_an_ctx_t *an_fin_ctx(fzl_analyzer_t *analyzer);
+
+#endif // INTERNALS_ANALYZER_H

include/compiler/internals/gen.h

@@ -0,0 +1,69 @@
+#ifndef INTERNALS_GEN_H
+#define INTERNALS_GEN_H
+
+#include <common/fzl_extern.h>
+#include <common/fzl_opcodes.h>
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/utils/fzl_const_pool.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+typedef struct
+{
+  bool error;
+  fzl_type_t type;
+  char *classname;
+} gen_res_t;
+
+extern gen_res_t gen_error;
+extern gen_res_t gen_ok_null;
+extern char *null_name;
+extern fzl_extern_type_t type_buf;
+
+bool gen_resolve_name(fzl_gen_t *gen, char *name, fzl_sym_t *sym);
+bool gen_resolve_type(fzl_gen_t *gen, fzl_token_t *tok, fzl_type_t *t, char *c);
+ssize_t gen_resolve_extern_type(fzl_gen_t *gen, char *name);
+bool gen_is_types_compatible(fzl_type_t t1, fzl_type_t t2, char *c1, char *c2);
+size_t gen_add_const(fzl_gen_t *gen, fzl_const_t c);
+void gen_op(fzl_gen_t *gen, fzl_opcode_t opcode);
+void gen_word(fzl_gen_t *gen, size_t word);
+
+fzl_gen_ctx_t *gen_ctx(fzl_gen_t *gen, fzl_gen_ctx_type_t type,
+                       fzl_node_t *node);
+fzl_gen_ctx_t *gen_fin_ctx(fzl_gen_t *gen);
+
+gen_res_t gen_common(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_extern(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_externfn(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_reference(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_struct(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_alias(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_handle(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_typedef(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_fmtstr(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_break(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_loop(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_class(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_construct(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_field(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_fn(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_return(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_unary_logical(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_compare(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_logical(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_condition(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_unary_math(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_declaration(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_identifier(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_block(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_call(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_literal(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_math(fzl_gen_t *gen, fzl_node_t *node);
+gen_res_t gen_assign(fzl_gen_t *gen, fzl_node_t *node);
+
+#endif // FZL_INTERNALS_GEN_H

include/compiler/internals/parser.h

@@ -0,0 +1,51 @@
+#ifndef INTERNALS_PARSER_H
+#define INTERNALS_PARSER_H
+
+#include "compiler/fzl_parser.h"
+#include "compiler/fzl_token.h"
+
+extern char plast_err[256];
+extern fzl_token_t *last_known_tok;
+
+extern fzl_token_t null_tok;
+extern fzl_token_t this_tok;
+
+fzl_token_t *peek(fzl_parser_t *parser);
+fzl_token_t *consume(fzl_parser_t *parser);
+bool is(fzl_parser_t *parser, fzl_toktype_t type);
+fzl_nodetype_t math_op_to_type(fzl_toktype_t type);
+fzl_nodetype_t unary_op_to_type(fzl_toktype_t type);
+
+fzl_node_t *pa_primary(fzl_parser_t *parser);
+fzl_node_t *pa_postfix(fzl_parser_t *parser);
+fzl_node_t *pa_unary(fzl_parser_t *parser);
+fzl_node_t *pa_power(fzl_parser_t *parser);
+fzl_node_t *pa_factor(fzl_parser_t *parser);
+fzl_node_t *pa_term(fzl_parser_t *parser);
+fzl_node_t *pa_cond(fzl_parser_t *parser);
+fzl_node_t *pa_and(fzl_parser_t *parser);
+fzl_node_t *pa_or(fzl_parser_t *parser);
+fzl_node_t *pa_new(fzl_parser_t *parser);
+fzl_node_t *pa_assignment(fzl_parser_t *parser);
+fzl_node_t *pa_expression(fzl_parser_t *parser);
+
+fzl_node_t *pa_struct(fzl_parser_t *parser);
+fzl_node_t *pa_ref(fzl_parser_t *parser);
+fzl_node_t *pa_typedef(fzl_parser_t *parser);
+fzl_node_t *pa_externfn(fzl_parser_t *parser);
+
+fzl_node_t *pa_class(fzl_parser_t *parser);
+fzl_node_t *pa_function(fzl_parser_t *parser);
+fzl_node_t *pa_return(fzl_parser_t *parser);
+fzl_node_t *pa_if(fzl_parser_t *parser);
+fzl_node_t *pa_block(fzl_parser_t *parser);
+fzl_node_t *pa_for(fzl_parser_t *parser);
+fzl_node_t *pa_while(fzl_parser_t *parser);
+fzl_node_t *pa_loop(fzl_parser_t *parser);
+fzl_node_t *pa_break(fzl_parser_t *parser);
+fzl_node_t *pa_extern(fzl_parser_t *parser);
+
+fzl_node_t *pa_statement(fzl_parser_t *parser);
+fzl_node_t *pa_program(fzl_parser_t *parser);
+
+#endif // INTERNALS_PARSER_H

include/compiler/internals/reader.h

@@ -0,0 +1,19 @@
+#ifndef INTERNALS_READER_H
+#define INTERNALS_READER_H
+
+#include <compiler/fzl_reader.h>
+#include <stddef.h>
+
+extern char last_err[256];
+
+size_t move(fzl_reader_t *reader, size_t len);
+void rd_comment(fzl_reader_t *reader);
+
+fzl_token_t *rd_name(fzl_reader_t *reader);
+fzl_token_t *rd_string_literal(fzl_reader_t *reader);
+fzl_token_t *rd_number(fzl_reader_t *reader);
+fzl_token_t *rd_single(fzl_reader_t *reader, fzl_toktype_t type);
+fzl_token_t *rd_double(fzl_reader_t *reader, fzl_toktype_t type);
+fzl_token_t *rd_fmtstr(fzl_reader_t *reader);
+
+#endif // INTERNALS_READER_H

include/compiler/internals/writer.h

@@ -0,0 +1,16 @@
+#ifndef INTERNALS_WRITER_H
+#define INTERNALS_WRITER_H
+
+#include <common/fzl_extern.h>
+#include <compiler/utils/fzl_const_pool.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+bool wr_consts(FILE *fd, fzl_const_hash_pool_t *consts);
+bool wr_extern_libs(FILE *fd, fzl_extern_lib_t *libs, size_t libs_count);
+bool wr_extern_types(FILE *fd, fzl_extern_type_t *types, size_t types_count);
+bool wr_extern_fns(FILE *fd, fzl_extern_fn_t *fns, size_t fns_count);
+bool wr_ops(FILE *fd, size_t *ops, size_t ops_count);
+
+#endif // INTERNALS_WRITER_H

include/compiler/utils/fzl_symtable.h

@@ -2,6 +2,7 @@
 #define FZL_SYMTABLE_H
 
 #include <common/fzl_types.h>
+#include <compiler/fzl_parser.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -19,8 +20,12 @@ typedef struct
 {
   char *name;
   fzl_type_t type;
+  fzl_node_t *node;
   size_t ip;
 
+  bool slot_set;
+  size_t slot;
+
   char *classname;
 } fzl_sym_t;
 
@@ -30,6 +35,8 @@ typedef struct
   size_t size;
   size_t remainder;
 
+  size_t free_slot;
+
   fzl_sym_t *symbols;
 } fzl_symtable_t;
 
@@ -37,13 +44,16 @@ typedef struct
 fzl_symtable_t *fzl_mksymt();
 
 // Put new entry into symtable
-fzl_symtable_res_t fzl_symt_put(fzl_symtable_t *symt, char *name,
+fzl_symtable_res_t fzl_symt_put(fzl_symtable_t *symt, fzl_node_t *node,
-                                fzl_type_t type, uint64_t ip);
+                                char *name, fzl_type_t type, uint64_t ip);
 
 // Assign class name to object type
 fzl_symtable_res_t fzl_symt_setobjclass(fzl_symtable_t *symt, char *name,
                                         char *classname);
 
+// Assign a local slot to a variable
+int fzl_symt_setslot(fzl_symtable_t *symt, char *name);
+
 // Get entry from specified symtable
 bool fzl_symt_get(fzl_symtable_t *symt, char *name, fzl_sym_t *res);
 

include/vm/fzl_vm.h

@@ -1,24 +1,24 @@
 #ifndef FZL_VM_H
 #define FZL_VM_H
 
-#include <common/fzl_value.h>
+#include <stdbool.h>
-#include <compiler/utils/fzl_const_pool.h> // NOTE: move outside compiler scope to common
 #include <stddef.h>
 #include <stdint.h>
 #include <vm/fzl_vm_env.h>
-#include <vm/fzl_vm_object.h>
+#include <vm/fzl_vm_extern.h>
+#include <vm/fzl_vm_reader.h>
 
 // VM descriptor
 typedef struct
 {
-  fzl_const_t *consts;
+  fzl_vm_reader_t *reader;
-  size_t consts_count;
+  fzl_vm_extern_t *prep_fns;
-
-  uint64_t *ops;
-  size_t ops_count;
 
   size_t ip;
 
+  bool allow_infinite;
+  size_t max_iter;
+
   // Data stack
   fzl_value_t dstack[256];
   size_t dtop;
@@ -33,7 +33,7 @@ typedef struct
 } fzl_vm_t;
 
 // Allocate FZL VM
-fzl_vm_t *fzl_mkvm(const char *filepath);
+fzl_vm_t *fzl_mkvm(fzl_vm_reader_t *reader);
 
 // Load and run code
 int fzl_vm_run(fzl_vm_t *vm);

include/vm/fzl_vm_extern.h

@@ -0,0 +1,35 @@
+#ifndef FZL_VM_EXTERN_H
+#define FZL_VM_EXTERN_H
+
+#include <ffi.h>
+#include <stddef.h>
+#include <vm/fzl_vm_reader.h>
+
+// Loaded extern function definition
+typedef struct
+{
+  void *func_ptr;
+  ffi_cif cif;
+  ffi_type **arg_types;
+} fzl_vm_sym_t;
+
+// Extern object descriptor
+typedef struct
+{
+  void **libs;
+  size_t libs_loaded;
+
+  fzl_vm_sym_t *syms;
+  size_t syms_loaded;
+} fzl_vm_extern_t;
+
+// Load externs
+fzl_vm_extern_t *fzl_vm_init_externs(fzl_vm_reader_t *reader);
+
+// Get last error from externs loader
+char *fzl_vm_externs_geterror();
+
+// Close and free externs
+void fzl_vm_free_externs(fzl_vm_extern_t *ex);
+
+#endif // FZL_VM_EXTERN_H

include/vm/fzl_vm_reader.h

@@ -0,0 +1,43 @@
+#ifndef FZL_VM_READER_H
+#define FZL_VM_READER_H
+
+#include <common/fzl_extern.h>
+#include <common/fzl_value.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+// Binary file reader descriptor
+typedef struct
+{
+  char *filepath;
+
+  fzl_value_t *consts;
+  uint16_t consts_count;
+
+  size_t *ops;
+  size_t ops_count;
+
+  char **extern_libs;
+  uint16_t extern_libs_count;
+
+  fzl_extern_type_t *extern_types;
+  uint16_t extern_types_count;
+
+  fzl_extern_fn_t *extern_fns;
+  uint16_t extern_fns_count;
+} fzl_vm_reader_t;
+
+// Allocate binary file reader
+fzl_vm_reader_t *fzl_vm_mkreader(char *filepath);
+
+// Read the file
+bool fzl_vm_read(fzl_vm_reader_t *reader);
+
+// Get last error message from the reader
+char *fzl_vm_getreadererror();
+
+// Free file reader
+void fzl_vm_freereader(fzl_vm_reader_t *reader);
+
+#endif // FZL_VM_READER_H

include/vm/internals/opcode.h

@@ -0,0 +1,112 @@
+#ifndef INTERNALS_OPCODE_H
+#define INTERNALS_OPCODE_H
+
+#include "vm/fzl_vm.h"
+#include <stddef.h>
+
+// Opcode handler descriptor
+typedef int (*opcode_handler)(fzl_vm_t *);
+
+extern char last_err[512];
+extern size_t last_jmp_ip;
+extern size_t total_jmp_on_same;
+
+void print_object(fzl_vm_object_t *obj);
+void print_err_data(fzl_vm_t *vm);
+void escape_recursive(fzl_vm_env_t *current, fzl_vm_env_t *parent,
+                      fzl_vm_object_t *obj);
+
+// --- stack ---
+
+extern const opcode_handler group_stack[];
+
+int op_loadconst(fzl_vm_t *vm);
+int op_call_builtin(fzl_vm_t *vm);
+int op_pushnum(fzl_vm_t *vm);
+int op_pushbool(fzl_vm_t *vm);
+
+// --- context ---
+
+extern const opcode_handler group_ctx[];
+
+int op_mk_envtable(fzl_vm_t *vm);
+int op_rm_envtable(fzl_vm_t *vm);
+int op_store(fzl_vm_t *vm);
+int op_lookup_env(fzl_vm_t *vm);
+int op_write(fzl_vm_t *vm);
+int op_load_local(fzl_vm_t *vm);
+int op_store_local(fzl_vm_t *vm);
+
+// --- flow ---
+
+extern const opcode_handler group_flow[];
+
+int op_jmp(fzl_vm_t *vm);
+int op_jz(fzl_vm_t *vm);
+
+// --- functions ---
+
+extern const opcode_handler group_fn[];
+
+int op_call(fzl_vm_t *vm);
+int op_ret(fzl_vm_t *vm);
+int op_call_extern(fzl_vm_t *vm);
+
+// --- objects ---
+
+extern const opcode_handler group_obj[];
+
+int op_alloc_object(fzl_vm_t *vm);
+int op_get_field(fzl_vm_t *vm);
+int op_set_field(fzl_vm_t *vm);
+int op_escape_object(fzl_vm_t *vm);
+int op_dereference(fzl_vm_t *vm);
+
+// --- math ---
+
+extern const opcode_handler group_math[];
+
+int op_add(fzl_vm_t *vm);
+int op_sub(fzl_vm_t *vm);
+int op_mul(fzl_vm_t *vm);
+int op_div(fzl_vm_t *vm);
+int op_pow(fzl_vm_t *vm);
+int op_mod(fzl_vm_t *vm);
+int op_neg(fzl_vm_t *vm);
+
+// --- strings ---
+
+extern const opcode_handler group_str[];
+
+int op_build_str(fzl_vm_t *vm);
+
+// --- conditions ---
+
+extern const opcode_handler group_cmp[];
+int op_cmp_eq(fzl_vm_t *vm);
+int op_cmp_neq(fzl_vm_t *vm);
+int op_cmp_lt(fzl_vm_t *vm);
+int op_cmp_lteq(fzl_vm_t *vm);
+int op_cmp_gt(fzl_vm_t *vm);
+int op_cmp_gteq(fzl_vm_t *vm);
+
+extern const opcode_handler group_strcmp[];
+int op_cmp_eq_str(fzl_vm_t *vm);
+int op_cmp_neq_str(fzl_vm_t *vm);
+
+extern const opcode_handler group_objcmp[];
+int op_cmp_eq_obj(fzl_vm_t *vm);
+int op_cmp_neq_obj(fzl_vm_t *vm);
+
+extern const opcode_handler group_and_or[];
+int op_and(fzl_vm_t *vm);
+int op_or(fzl_vm_t *vm);
+
+extern const opcode_handler group_not[];
+int op_not(fzl_vm_t *vm);
+
+// ------------------------
+
+extern const opcode_handler *const master_tbl[];
+
+#endif // INTERNALS_OPCODE_H

include/vm/internals/reader.h

@@ -0,0 +1,24 @@
+#ifndef INTERNALS_VM_READER_H
+#define INTERNALS_VM_READER_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <vm/fzl_vm_reader.h>
+
+extern char internal_error[256];
+
+bool vm_rd_char(FILE *fd, size_t count, char *outbuf);
+bool vm_rd_u16(FILE *fd, size_t count, uint16_t *outbuf);
+bool vm_rd_word(FILE *fd, size_t count, size_t *outbuf);
+
+bool vm_rd_header(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_sections_sz(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_consts(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_extern_libs(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_extern_types(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_extern_fns(fzl_vm_reader_t *reader, FILE *fd);
+bool vm_rd_ops(fzl_vm_reader_t *reader, FILE *fd);
+
+#endif // INTERNALS_VM_READER_H

scripts/benchmark.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""Run an FZL VM benchmark and report wall-clock timing statistics."""
+
+import argparse
+import statistics
+import subprocess
+import sys
+import time
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--runs", type=int, default=7, help="measured runs")
+    parser.add_argument("--warmup", type=int, default=2, help="warm-up runs")
+    parser.add_argument("--max-iter", type=int, default=2_000_000)
+    parser.add_argument("--vm", required=True, help="path to the fz executable")
+    parser.add_argument("--program", required=True, help="compiled .fzb program")
+    args = parser.parse_args()
+
+    if args.runs < 1 or args.warmup < 0 or args.max_iter < 1:
+        parser.error("runs/max-iter must be positive and warmup must be non-negative")
+
+    command = [args.vm, "--max-iter", str(args.max_iter), args.program]
+
+    for _ in range(args.warmup):
+        result = subprocess.run(command, capture_output=True, text=True)
+        if result.returncode != 0:
+            sys.stderr.write(result.stdout)
+            sys.stderr.write(result.stderr)
+            raise SystemExit(result.returncode)
+
+    measurements = []
+    for _ in range(args.runs):
+        start = time.perf_counter()
+        result = subprocess.run(
+            command, capture_output=True, text=True
+        )
+        elapsed = time.perf_counter() - start
+        if result.returncode != 0:
+            sys.stderr.write(result.stdout)
+            sys.stderr.write(result.stderr)
+            raise SystemExit(result.returncode)
+        measurements.append(elapsed)
+
+    print(f"Runs:   {args.runs} (warm-up: {args.warmup})")
+    print(f"Median: {statistics.median(measurements):.6f} s")
+    print(f"Mean:   {statistics.mean(measurements):.6f} s")
+    print(f"Min:    {min(measurements):.6f} s")
+    print(f"Max:    {max(measurements):.6f} s")
+
+
+if __name__ == "__main__":
+    main()

src/compiler/analyzer/an_assign.c

@@ -0,0 +1,51 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stdio.h>
+
+// Analyze assigns
+fzl_an_res_t analyze_assign(fzl_analyzer_t *analyzer, fzl_node_t *assign_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!assign_node || assign_node->type != FZL_NODETYPE_ASSIGN)
+  {
+    an_push_error(analyzer, NULL, "node is not assignment");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_node_t *left      = assign_node->binary_op.left;
+  fzl_an_res_t leftside = analyze_common(analyzer, left);
+  if (leftside.error)
+    return (fzl_an_res_t){.error = true};
+
+  fzl_an_res_t rightside =
+      analyze_common(analyzer, assign_node->binary_op.right);
+  if (rightside.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (left->type != FZL_NODETYPE_DECLARATION &&
+      left->type != FZL_NODETYPE_IDENTIFIER && left->type != FZL_NODETYPE_FIELD)
+  {
+    an_push_error(analyzer, left->token,
+                  "left side must be one of these: declaration, identifier or "
+                  "field access");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (!an_is_compatible(leftside.type, rightside.type, leftside.classname,
+                        rightside.classname))
+  {
+    snprintf(an_problem, sizeof(an_problem),
+             "incompatible types - '%s' is expected, got '%s'",
+             an_typetostr(leftside.type, leftside.classname),
+             an_typetostr(rightside.type, rightside.classname));
+    an_push_error(analyzer, assign_node->binary_op.right->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+}

src/compiler/analyzer/an_binmath.c

@@ -0,0 +1,51 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stdio.h>
+
+// Analyze binary arithmetics
+fzl_an_res_t analyze_binmath(fzl_analyzer_t *analyzer, fzl_node_t *bin_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!bin_node || (bin_node->type != FZL_NODETYPE_ADD &&
+                    bin_node->type != FZL_NODETYPE_SUB &&
+                    bin_node->type != FZL_NODETYPE_MUL &&
+                    bin_node->type != FZL_NODETYPE_DIV &&
+                    bin_node->type != FZL_NODETYPE_POW &&
+                    bin_node->type != FZL_NODETYPE_MOD))
+  {
+    an_push_error(analyzer, NULL, "node is not binary math operator");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t left = analyze_common(analyzer, bin_node->binary_op.left);
+  if (left.error)
+    return (fzl_an_res_t){.error = true};
+
+  fzl_an_res_t right = analyze_common(analyzer, bin_node->binary_op.right);
+  if (right.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (left.type < FZL_TYPE_INT8)
+  {
+    snprintf(an_problem, sizeof(an_problem),
+             "integer type is expected, got '%s'",
+             an_typetostr(left.type, left.classname));
+    an_push_error(analyzer, bin_node->binary_op.left->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (right.type < FZL_TYPE_INT8)
+  {
+    snprintf(an_problem, sizeof(an_problem),
+             "integer type is expected, got '%s'",
+             an_typetostr(right.type, right.classname));
+    an_push_error(analyzer, bin_node->binary_op.right->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){.error = false, .type = left.type, .classname = NULL};
+}

src/compiler/analyzer/an_block.c

@@ -0,0 +1,99 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+// Analyze block
+fzl_an_res_t analyze_block(fzl_analyzer_t *analyzer, fzl_node_t *block_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!block_node || block_node->type != FZL_NODETYPE_BLOCK)
+  {
+    snprintf(an_problem, sizeof(an_problem), "node is not a block");
+    an_push_error(analyzer, NULL, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_UNNECESSARY);
+
+  bool has_return = false;
+  bool error      = false;
+  for (size_t i = 0; i < block_node->list.entry_count; i++)
+  {
+    if (has_return)
+      an_push_warning(analyzer, block_node->list.entries[i]->token,
+                      "this statement will never execute");
+
+    fzl_an_res_t entry_res =
+        analyze_common(analyzer, block_node->list.entries[i]);
+    if (entry_res.error)
+      error = true;
+
+    if (block_node->list.entries[i]->type == FZL_NODETYPE_RETURN)
+      has_return = true;
+  }
+
+  fzl_an_ctx_t *fnctx = analyzer->ctx;
+  while (fnctx != NULL)
+  {
+    if (fnctx && fnctx->type == FZL_AN_CTX_TYPE_FUNCTION)
+      break;
+
+    fnctx = fnctx->parent;
+  }
+
+  if (fnctx && fnctx->type == FZL_AN_CTX_TYPE_FUNCTION)
+  {
+    bool found         = false;
+    fzl_type_t rettype = an_toktotype(analyzer, fnctx->fn->fn.type, &found);
+    char *classname    = NULL;
+    char *rettype_str  = an_typetostr(rettype, classname);
+
+    if (!found)
+    {
+      snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+               (char *)fnctx->fn->fn.type->value);
+      an_push_error(analyzer, fnctx->fn->fn.type, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (rettype == FZL_TYPE_OBJECT)
+      classname = (char *)fnctx->fn->fn.type->value;
+
+    if (rettype != FZL_TYPE_NULL)
+    {
+      if (!has_return || block_node->list.entry_count < 1)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "'return <%s>' is expected in the function with non-null "
+                 "return type",
+                 rettype_str);
+        an_push_error(analyzer, block_node->token, an_problem);
+        return (fzl_an_res_t){.error = true};
+      }
+
+      fzl_node_t *last_node =
+          block_node->list.entries[block_node->list.entry_count - 1];
+      if (last_node->type != FZL_NODETYPE_RETURN)
+      {
+        // NOTE: replace with ghost walker to check if all branch return an
+        // expected value type
+        snprintf(an_problem, sizeof(an_problem),
+                 "expected last statement in block to be 'return <%s>'",
+                 rettype_str);
+        an_push_error(analyzer, last_node->token, an_problem);
+        return (fzl_an_res_t){.error = true};
+      }
+    }
+  }
+
+  an_fin_ctx(analyzer);
+
+  return (fzl_an_res_t){.error = error, .type = FZL_TYPE_NULL};
+}

src/compiler/analyzer/an_break.c

@@ -0,0 +1,36 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+
+// Analyze break node
+fzl_an_res_t analyze_break(fzl_analyzer_t *analyzer, fzl_node_t *break_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!break_node || break_node->type != FZL_NODETYPE_BREAK)
+  {
+    an_push_error(analyzer, NULL, "node is not a break statement");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_ctx_t *ctx = analyzer->ctx;
+  while (ctx != NULL)
+  {
+    if (ctx && ctx->type == FZL_AN_CTX_TYPE_LOOP)
+      break;
+
+    ctx = ctx->parent;
+  }
+
+  if (!ctx || ctx->type != FZL_AN_CTX_TYPE_LOOP)
+  {
+    an_push_error(analyzer, break_node->token,
+                  "cannot use 'break' outside the loop");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+}

src/compiler/analyzer/an_call.c

@@ -0,0 +1,278 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *tmp_method_name = NULL;
+char *tmp_fnname      = NULL;
+char *tmp_classname   = NULL;
+
+// Try to get symbol name from callee
+char *resolve_callee(fzl_analyzer_t *analyzer, fzl_node_t *callee, bool *method)
+{
+  *method = false;
+
+  if (callee->type == FZL_NODETYPE_IDENTIFIER)
+    return (char *)callee->token->value;
+
+  if (callee->type != FZL_NODETYPE_FIELD)
+  {
+    an_push_error(analyzer, callee->token, "unknown call format");
+    return NULL;
+  }
+
+  *method                 = true;
+  fzl_an_res_t parent_res = analyze_common(analyzer, callee->memb.parent);
+  if (parent_res.type != FZL_TYPE_OBJECT || !parent_res.classname)
+    return NULL;
+
+  char *fn_name         = callee->memb.field->token->value;
+  tmp_fnname            = fn_name;
+  tmp_classname         = parent_res.classname;
+  size_t classname_len  = strlen(parent_res.classname);
+  size_t methodname_len = strlen(fn_name);
+  tmp_method_name       = malloc(classname_len + methodname_len + 2);
+  if (!tmp_method_name)
+  {
+    an_push_error(analyzer, callee->token, "out of memory");
+    return NULL;
+  }
+
+  strcpy(tmp_method_name, parent_res.classname);
+  tmp_method_name[classname_len] = '_';
+  strcpy(tmp_method_name + classname_len + 1, fn_name);
+  tmp_method_name[classname_len + methodname_len + 1] = 0;
+
+  return tmp_method_name;
+}
+
+// Analyze call node
+fzl_an_res_t analyze_call(fzl_analyzer_t *analyzer, fzl_node_t *call_node)
+{
+  if (!call_node || call_node->type != FZL_NODETYPE_CALL)
+  {
+    an_push_error(analyzer, NULL, "node is not call");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_node_t *callee = call_node->call.callee;
+
+  bool is_method    = false;
+  char *callee_name = resolve_callee(analyzer, callee, &is_method);
+  if (!callee_name)
+  {
+    an_push_error(analyzer, callee->token, "expression is not callable");
+
+    if (tmp_method_name != NULL)
+    {
+      free(tmp_method_name);
+      tmp_method_name = NULL;
+    }
+
+    return (fzl_an_res_t){.error = true};
+  }
+
+  // NOTE: move into `compiler/analyzer/builtins.c`
+  if (strcmp(callee_name, "printline") == 0 || strcmp(callee_name, "exit") == 0)
+  {
+    if (call_node->call.args_count != 1)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "'%s' builtin should be called with 1 argument instead of %zu",
+               callee_name, call_node->call.args_count);
+      an_push_error(analyzer, call_node->token, an_problem);
+
+      if (tmp_method_name != NULL)
+      {
+        free(tmp_method_name);
+        tmp_method_name = NULL;
+      }
+
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (tmp_method_name != NULL)
+    {
+      free(tmp_method_name);
+      tmp_method_name = NULL;
+    }
+
+    return (fzl_an_res_t){
+        .error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+  }
+
+  fzl_sym_t sym;
+  bool sym_found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((sym_found = fzl_symt_get(analyzer->symbols[i], callee_name, &sym)))
+      break;
+  }
+
+  if (!sym_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "cannot resolve symbol '%s'",
+             callee_name);
+    an_push_error(analyzer, call_node->token, an_problem);
+
+    if (tmp_method_name != NULL)
+    {
+      free(tmp_method_name);
+      tmp_method_name = NULL;
+    }
+
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (sym.node->type != FZL_NODETYPE_FUNCTION &&
+      sym.node->type != FZL_NODETYPE_EXTERN_FN)
+  {
+    snprintf(an_problem, sizeof(an_problem), "'%s' is not callable",
+             callee_name);
+    an_push_error(analyzer, call_node->token, an_problem);
+
+    if (tmp_method_name != NULL)
+    {
+      free(tmp_method_name);
+      tmp_method_name = NULL;
+    }
+
+    return (fzl_an_res_t){.error = true};
+  }
+
+  size_t offset     = is_method ? 1 : 0;
+  size_t args_count = sym.node->type == FZL_NODETYPE_EXTERN_FN
+                          ? sym.node->ext_fn.args_count
+                          : sym.node->fn.args_count;
+  if ((args_count - offset) != call_node->call.args_count)
+  {
+    if (is_method)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "method '%s.%s' is expecting %zu argument(s), got %zu",
+               tmp_classname, tmp_fnname, args_count,
+               call_node->call.args_count - offset);
+    }
+    else
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "function '%s' is expecting %zu argument(s), got %zu",
+               callee_name, args_count, call_node->call.args_count - offset);
+    }
+    an_push_error(analyzer, call_node->token, an_problem);
+
+    if (tmp_method_name != NULL)
+    {
+      free(tmp_method_name);
+      tmp_method_name = NULL;
+    }
+
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_node_t **args = sym.node->type == FZL_NODETYPE_EXTERN_FN
+                          ? sym.node->ext_fn.args
+                          : sym.node->fn.args;
+  for (size_t i = offset; i < sym.node->fn.args_count; i++)
+  {
+    fzl_node_t *arg     = args[i];
+    bool found          = false;
+    fzl_type_t req_type = an_toktotype(analyzer, arg->var.type, &found);
+    char *req_classname = NULL;
+
+    if (!found)
+    {
+      snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+               (char *)arg->var.type->value);
+      an_push_error(analyzer, arg->var.type, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (req_type == FZL_TYPE_OBJECT)
+      req_classname = arg->var.type->value;
+
+    fzl_an_res_t got =
+        analyze_common(analyzer, call_node->call.args[i - offset]);
+    if (got.error)
+    {
+      if (tmp_method_name != NULL)
+      {
+        free(tmp_method_name);
+        tmp_method_name = NULL;
+      }
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (!an_is_compatible(req_type, got.type, req_classname, got.classname))
+    {
+      if (is_method)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "method '%s.%s' is expecting %zu argument to have type '%s', "
+                 "got '%s'",
+                 tmp_classname, tmp_fnname, i + 1 - offset,
+                 an_typetostr(req_type, req_classname),
+                 an_typetostr(got.type, got.classname));
+      }
+      else
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "function '%s' is expecting %zu argument to have type '%s', "
+                 "got '%s'",
+                 callee_name, i + 1 - offset,
+                 an_typetostr(req_type, req_classname),
+                 an_typetostr(got.type, got.classname));
+      }
+      an_push_error(analyzer, call_node->token, an_problem);
+
+      if (tmp_method_name != NULL)
+      {
+        free(tmp_method_name);
+        tmp_method_name = NULL;
+      }
+
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  bool type_found = false;
+  fzl_token_t *ret_tok = NULL;
+  void        *ret_name = NULL;
+
+  if (sym.node->type == FZL_NODETYPE_EXTERN_FN)
+  {
+    ret_tok = sym.node->ext_fn.type;
+    ret_name = sym.node->ext_fn.name;
+  }
+  else
+  {
+    ret_tok = sym.node->fn.type;
+    ret_name = sym.node->fn.name;
+  }
+
+  fzl_type_t type = an_toktotype(analyzer, ret_tok, &type_found);
+  char *classname = sym.classname;
+
+  if (!type_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+             (char *)ret_name);
+    an_push_error(analyzer, ret_tok, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (tmp_method_name != NULL)
+  {
+    free(tmp_method_name);
+    tmp_method_name = NULL;
+  }
+
+  return (fzl_an_res_t){.error = false, .type = type, .classname = classname};
+}

src/compiler/analyzer/an_class.c

@@ -0,0 +1,72 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdio.h>
+
+// Analyze class declaration
+fzl_an_res_t analyze_class(fzl_analyzer_t *analyzer, fzl_node_t *class_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!class_node || class_node->type != FZL_NODETYPE_CLASS)
+  {
+    an_push_error(analyzer, NULL, "node is not class");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *classname   = (char *)class_node->class.name->value;
+  fzl_an_ctx_t *ctx = an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_CLASS);
+  ctx->classname    = classname;
+
+  fzl_sym_t sym;
+  bool sym_found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((sym_found = fzl_symt_get(analyzer->symbols[i], classname, &sym)))
+      break;
+  }
+
+  fzl_symtable_res_t res =
+      fzl_symt_put(analyzer->symbols[analyzer->symbols_top - 2], class_node,
+                   classname, FZL_TYPE_NULL, 0);
+
+  if (res != FZL_SYMTABLE_RESULT_OK)
+  {
+    if (res == FZL_SYMTABLE_RESULT_EXISTS)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "name '%s' already has been declared", classname);
+      an_push_error(analyzer, class_node->token, an_problem);
+    }
+    else
+    {
+      snprintf(an_problem, sizeof(an_problem), "cannot store name '%s'",
+               classname);
+      an_push_error(analyzer, class_node->token, an_problem);
+    }
+
+    an_fin_ctx(analyzer);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  bool error = false;
+  for (size_t i = 0; i < class_node->class.fields_count; i++)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, class_node->class.fields[i]);
+    if (res.error)
+      error = true;
+  }
+
+  for (size_t i = 0; i < class_node->class.methods_count; i++)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, class_node->class.methods[i]);
+    if (res.error)
+      error = true;
+  }
+
+  an_fin_ctx(analyzer);
+  return (fzl_an_res_t){.error = error, .type = FZL_TYPE_NULL};
+}

src/compiler/analyzer/an_common.c

@@ -0,0 +1,161 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+// Analyzer main function
+fzl_an_res_t analyze_common(fzl_analyzer_t *analyzer, fzl_node_t *node)
+{
+  if (!analyzer || !node)
+    return (fzl_an_res_t){.error = true};
+
+  fzl_an_res_t res = {.error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+  switch (node->type)
+  {
+    case FZL_NODETYPE_EXTERN:
+      res = analyze_extern(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_EXTERN_FN:
+      res = analyze_externfn(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_REFERENCE:
+      res = analyze_ref(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_STRUCT:
+      res = analyze_struct(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_ALIAS:
+      res.type = an_toktotype(analyzer, node->token, NULL);
+      break;
+
+    case FZL_NODETYPE_HANDLE:
+      res.type = FZL_TYPE_HANDLE;
+      break;
+
+    case FZL_NODETYPE_TYPEDEF:
+      res = analyze_typedef(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_FMT_STRING:
+      res = analyze_strfmt(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_ASSIGN:
+      res = analyze_assign(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_NOT:
+      res = analyze_unarycond(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_OR:
+    case FZL_NODETYPE_AND:
+    case FZL_NODETYPE_LESS:
+    case FZL_NODETYPE_LESS_EQUAL:
+    case FZL_NODETYPE_GREATER:
+    case FZL_NODETYPE_GREATER_EQUAL:
+    case FZL_NODETYPE_EQUAL:
+    case FZL_NODETYPE_NEQUAL:
+      res = analyze_condition(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_UNARY_MINUS:
+    case FZL_NODETYPE_UNARY_PLUS:
+      res = analyze_unarymath(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_ADD:
+    case FZL_NODETYPE_SUB:
+    case FZL_NODETYPE_MUL:
+    case FZL_NODETYPE_DIV:
+    case FZL_NODETYPE_POW:
+    case FZL_NODETYPE_MOD:
+      res = analyze_binmath(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_BREAK:
+      res = analyze_break(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_LOOP:
+      res = analyze_loop(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_CONSTRUCT:
+      res = analyze_construct(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_DECLARATION:
+      res = analyze_declaration(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_FIELD:
+      res = analyze_field(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_CLASS:
+      res = analyze_class(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_RETURN:
+      res = analyze_return(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_FUNCTION:
+      res = analyze_function(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_CONDITIONAL:
+      res = analyze_conditional(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_IDENTIFIER:
+      res = analyze_identifier(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_BLOCK:
+      res = analyze_block(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_CALL:
+      res = analyze_call(analyzer, node);
+      break;
+
+    case FZL_NODETYPE_LITERAL:
+      switch (node->token->type)
+      {
+        case FZL_TOKTYPE_STR_LITERAL:
+          res.type = FZL_TYPE_STRING;
+          break;
+
+        case FZL_TOKTYPE_NUM_LITERAL:
+          res.type = FZL_TYPE_INT;
+          break;
+
+        case FZL_TOKTYPE_BOOL_LITERAL:
+          res.type = FZL_TYPE_BOOL;
+          break;
+
+        case FZL_TOKTYPE_NULL_LITERAL:
+          res.type      = FZL_TYPE_OBJECT;
+          res.classname = "null";
+          break;
+
+        default:
+          an_push_error(analyzer, node->token, "unknown literal type");
+          res.error = true;
+          break;
+      }
+      break;
+  }
+
+  return res;
+}

src/compiler/analyzer/an_condition.c

@@ -0,0 +1,115 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stdio.h>
+
+// Analyze binary conditional nodes
+fzl_an_res_t analyze_condition(fzl_analyzer_t *analyzer, fzl_node_t *cond_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!cond_node || (cond_node->type != FZL_NODETYPE_OR &&
+                     cond_node->type != FZL_NODETYPE_AND &&
+                     cond_node->type != FZL_NODETYPE_LESS &&
+                     cond_node->type != FZL_NODETYPE_LESS_EQUAL &&
+                     cond_node->type != FZL_NODETYPE_GREATER &&
+                     cond_node->type != FZL_NODETYPE_GREATER_EQUAL &&
+                     cond_node->type != FZL_NODETYPE_EQUAL &&
+                     cond_node->type != FZL_NODETYPE_NEQUAL))
+  {
+    an_push_error(analyzer, NULL, "node is not a binary conditional operator");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t left = analyze_common(analyzer, cond_node->binary_op.left);
+  if (left.error)
+    return (fzl_an_res_t){.error = true};
+
+  fzl_an_res_t right = analyze_common(analyzer, cond_node->binary_op.right);
+  if (right.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (cond_node->type == FZL_NODETYPE_OR || cond_node->type == FZL_NODETYPE_AND)
+  {
+    if (left.type != FZL_TYPE_BOOL)
+      an_push_warning(analyzer, cond_node->binary_op.left->token,
+                      "left operand is not resulting with boolean type");
+
+    if (right.type != FZL_TYPE_BOOL)
+      an_push_warning(analyzer, cond_node->binary_op.right->token,
+                      "right operand is not resulting with boolean type");
+  }
+  else if (cond_node->type == FZL_NODETYPE_LESS ||
+           cond_node->type == FZL_NODETYPE_LESS_EQUAL ||
+           cond_node->type == FZL_NODETYPE_GREATER ||
+           cond_node->type == FZL_NODETYPE_GREATER_EQUAL)
+  {
+    if (left.type < FZL_TYPE_INT8)
+    {
+      an_push_error(analyzer, cond_node->binary_op.left->token,
+                    "left operand must have integer type");
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (left.type < FZL_TYPE_INT8)
+    {
+      an_push_error(analyzer, cond_node->binary_op.left->token,
+                    "right operand must have integer type");
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+  else if (left.type >= FZL_TYPE_INT8)
+  {
+    if (right.type < FZL_TYPE_INT8)
+    {
+      an_push_error(analyzer, cond_node->binary_op.right->token,
+                    "right operand must have integer type");
+      return (fzl_an_res_t){.error = true};
+    }
+
+    return (fzl_an_res_t){
+        .error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+  }
+  else if (left.type == FZL_TYPE_OBJECT)
+  {
+    if (!left.classname || !right.classname)
+    {
+      an_push_error(analyzer, cond_node->binary_op.left->token,
+                    "unhandled error :(");
+      return (fzl_an_res_t){.error = true};
+    }
+
+    if (!an_is_compatible(left.type, right.type, left.classname,
+                          right.classname))
+    {
+      snprintf(an_problem, sizeof(an_problem), "'%s' and '%s' are incompatible",
+               an_typetostr(left.type, left.classname),
+               an_typetostr(right.type, right.classname));
+      an_push_error(analyzer, cond_node->binary_op.right->token, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+  else if (left.type == FZL_TYPE_STRING)
+  {
+    if (right.type != FZL_TYPE_STRING)
+    {
+      an_push_error(analyzer, cond_node->binary_op.right->token,
+                    "right operand must be a string");
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+  else if (!an_is_compatible(left.type, right.type, left.classname,
+                             right.classname))
+  {
+    snprintf(an_problem, sizeof(an_problem),
+             "equality not supported between %s and %s",
+             an_typetostr(left.type, left.classname),
+             an_typetostr(right.type, right.classname));
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+}

src/compiler/analyzer/an_conditional.c

@@ -0,0 +1,45 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <stdio.h>
+
+// Analyze conditional statement
+fzl_an_res_t analyze_conditional(fzl_analyzer_t *analyzer, fzl_node_t *cond)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!cond || cond->type != FZL_NODETYPE_CONDITIONAL)
+  {
+    an_push_error(analyzer, NULL, "provided node is a condition");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t cond_res = analyze_common(analyzer, cond->cond.condition);
+  fzl_an_res_t true_res = analyze_common(analyzer, cond->cond.true_block);
+
+  if (cond->cond.else_block)
+  {
+    fzl_an_res_t else_res = analyze_common(analyzer, cond->cond.else_block);
+    if (else_res.error)
+      return (fzl_an_res_t){.error = true};
+  }
+
+  if (cond_res.error || true_res.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (cond_res.type != FZL_TYPE_BOOL)
+    an_push_warning(analyzer, cond->cond.condition->token,
+                    "resulting type is not bool");
+
+  if (cond->cond.condition->token->type == FZL_TOKTYPE_BOOL_LITERAL)
+  {
+    snprintf(an_problem, sizeof(an_problem), "condition is always %s",
+             (char *)cond->cond.condition->token->value);
+    an_push_warning(analyzer, cond->cond.condition->token, an_problem);
+  }
+
+  return (fzl_an_res_t){.error = false, .type = FZL_TYPE_NULL};
+}

src/compiler/analyzer/an_construct.c

@@ -0,0 +1,39 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Analyze class construct
+fzl_an_res_t analyze_construct(fzl_analyzer_t *analyzer, fzl_node_t *construct)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!construct || construct->type != FZL_NODETYPE_CONSTRUCT)
+  {
+    an_push_error(analyzer, NULL, "node is not a construct");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *classname = (char *)construct->construct.name->token->value;
+  fzl_sym_t sym;
+  bool sym_found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((sym_found = fzl_symt_get(analyzer->symbols[i], classname, &sym)))
+      break;
+  }
+
+  if (!sym_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "class '%s' not found", classname);
+    an_push_error(analyzer, construct->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_OBJECT, .classname = classname};
+}

src/compiler/analyzer/an_declaration.c

@@ -0,0 +1,76 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Analyze variable/field/argument declaration
+fzl_an_res_t analyze_declaration(fzl_analyzer_t *analyzer, fzl_node_t *decl)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!decl || decl->type != FZL_NODETYPE_DECLARATION)
+  {
+    an_push_error(analyzer, NULL, "node is not a declaration");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *name      = (char *)decl->var.identifier->token->value;
+  bool type_found = false;
+  fzl_type_t type = an_toktotype(analyzer, decl->var.type, &type_found);
+
+  if (!type_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+             (char *)decl->var.type->value);
+    an_push_error(analyzer, decl->var.type, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *classname = NULL;
+  if (type == FZL_TYPE_OBJECT)
+    classname = decl->var.type->value;
+
+  fzl_symtable_res_t res = fzl_symt_put(
+      analyzer->symbols[analyzer->symbols_top - 1], decl, name, type, 0);
+  if (res != FZL_SYMTABLE_RESULT_OK)
+  {
+    if (res == FZL_SYMTABLE_RESULT_EXISTS)
+      snprintf(an_problem, sizeof(an_problem), "'%s' already has been declared",
+               name);
+    else
+      snprintf(an_problem, sizeof(an_problem), "cannot store '%s'", name);
+
+    an_push_error(analyzer, decl->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (type == FZL_TYPE_OBJECT)
+  {
+    fzl_sym_t class;
+    bool class_found = false;
+    for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+    {
+      if ((class_found = fzl_symt_get(analyzer->symbols[i],
+                                      decl->var.type->value, &class)))
+        break;
+    }
+
+    if (!class_found || class.node->type != FZL_NODETYPE_CLASS)
+    {
+      snprintf(an_problem, sizeof(an_problem), "class '%s' does not exists",
+               (char *)decl->var.type->value);
+      an_push_error(analyzer, decl->var.type, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+
+    fzl_symt_setobjclass(analyzer->symbols[analyzer->symbols_top - 1], name,
+                         classname);
+  }
+
+  return (fzl_an_res_t){.error = false, .type = type, .classname = classname};
+}

src/compiler/analyzer/an_extern.c

@@ -0,0 +1,50 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stddef.h>
+#include <stdio.h>
+
+// Analyze extern block definition
+fzl_an_res_t analyze_extern(fzl_analyzer_t *analyzer, fzl_node_t *extern_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!extern_node || extern_node->type != FZL_NODETYPE_EXTERN)
+  {
+    an_push_error(analyzer, NULL, "node is not an extern block");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (extern_node->ext.typedefs_count < 1 && extern_node->ext.fns_count < 1)
+    an_push_warning(analyzer, extern_node->token, "extern is empty");
+
+  for (size_t i = 0; i < extern_node->ext.typedefs_count; i++)
+  {
+    fzl_node_t *node = extern_node->ext.typedefs[i];
+    fzl_an_res_t res = analyze_common(analyzer, node);
+    if (res.error)
+      return (fzl_an_res_t){.error = true};
+
+    if (node->type != FZL_NODETYPE_TYPEDEF &&
+        node->type != FZL_NODETYPE_EXTERN_FN)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "unexpected statement '%s' inside extern block",
+               (char *)node->token->value);
+      an_push_error(analyzer, node->token, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  for (size_t i = 0; i < extern_node->ext.fns_count; i++)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, extern_node->ext.fns[i]);
+    if (res.error)
+      return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+}

src/compiler/analyzer/an_externfn.c

@@ -0,0 +1,79 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+// Analyze external function definition
+fzl_an_res_t analyze_externfn(fzl_analyzer_t *analyzer, fzl_node_t *externfn)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!externfn || externfn->type != FZL_NODETYPE_EXTERN_FN)
+  {
+    an_push_error(analyzer, NULL, "node is not an external function");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_UNNECESSARY);
+
+  for (size_t i = 0; i < externfn->ext_fn.args_count; i++)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, externfn->ext_fn.args[i]);
+    if (res.error)
+      return (fzl_an_res_t){.error = true};
+  }
+
+  if (externfn->ext_fn.type->type == FZL_TOKTYPE_NAME)
+  {
+    fzl_sym_t sym;
+    bool found = false;
+    for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+    {
+      if ((found = fzl_symt_get(analyzer->symbols[i],
+                                (char *)externfn->ext_fn.type->value, &sym)))
+        break;
+    }
+
+    if (!found)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "cannot find '%s' used as return type",
+               (char *)externfn->ext_fn.type->value);
+      an_push_error(analyzer, externfn->ext_fn.type, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  fzl_symtable_res_t wrres =
+      fzl_symt_put(analyzer->symbols[0], externfn,
+                   (char *)externfn->ext_fn.name, FZL_TYPE_EXTERN_FN, 0);
+  if (wrres != FZL_SYMTABLE_RESULT_OK)
+  {
+    if (wrres == FZL_SYMTABLE_RESULT_EXISTS)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "symbol '%s' already has been declared", externfn->ext_fn.name);
+      an_push_error(analyzer, externfn->token, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+    else
+    {
+      snprintf(an_problem, sizeof(an_problem), "cannot store symbol '%s'",
+               externfn->ext_fn.name);
+    }
+
+    an_push_error(analyzer, externfn->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  an_fin_ctx(analyzer);
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_EXTERN_FN, .classname = NULL};
+}

src/compiler/analyzer/an_field.c

@@ -0,0 +1,90 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+// Analyze field access
+fzl_an_res_t analyze_field(fzl_analyzer_t *analyzer, fzl_node_t *field)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!field || field->type != FZL_NODETYPE_FIELD)
+  {
+    an_push_error(analyzer, NULL, "node is not field access");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t parent = analyze_common(analyzer, field->memb.parent);
+  if (parent.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (parent.type != FZL_TYPE_OBJECT || parent.classname == NULL)
+  {
+    snprintf(an_problem, sizeof(an_problem), "access to non-object value (%s)",
+             an_typetostr(parent.type, parent.classname));
+    an_push_error(analyzer, field->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *field_name = field->memb.field->token->value;
+  fzl_sym_t sym;
+  bool sym_found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((sym_found =
+             fzl_symt_get(analyzer->symbols[i], parent.classname, &sym)))
+      break;
+  }
+
+  if (!sym_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "class '%s' not found",
+             parent.classname);
+    an_push_error(analyzer, field->parent->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_node_t *field_node = NULL;
+  for (size_t i = 0; i < sym.node->class.fields_count; i++)
+  {
+    if (strcmp(sym.node->class.fields[i]->var.identifier->token->value,
+               field_name) == 0)
+    {
+      field_node = sym.node->class.fields[i];
+      break;
+    }
+  }
+
+  if (field_node == NULL)
+  {
+    snprintf(an_problem, sizeof(an_problem), "field '%s.%s' does not exists",
+             parent.classname, field_name);
+    an_push_error(analyzer, field->memb.field->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  bool type_found = false;
+  fzl_type_t field_type =
+      an_toktotype(analyzer, field_node->var.type, &type_found);
+
+  if (!type_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+             (char *)field_node->var.type->value);
+    an_push_error(analyzer, field_node->var.type, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *classname = NULL;
+  if (field_type == FZL_TYPE_OBJECT)
+    classname = field_node->var.type->value;
+
+  return (fzl_an_res_t){
+      .error = false, .type = field_type, .classname = classname};
+}

src/compiler/analyzer/an_function.c

@@ -0,0 +1,139 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+fzl_an_res_t analyze_function(fzl_analyzer_t *analyzer, fzl_node_t *fn_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!fn_node || fn_node->type != FZL_NODETYPE_FUNCTION)
+  {
+    an_push_error(analyzer, NULL, "node is not a function");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_ctx_t *fnctx = an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_FUNCTION);
+  fnctx->fn           = fn_node;
+
+  for (size_t i = 0; i < fn_node->fn.args_count; i++)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, fn_node->fn.args[i]);
+    if (res.error)
+      return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_ctx_t *ctx = analyzer->ctx;
+  while (ctx != NULL)
+  {
+    if (ctx->type == FZL_AN_CTX_TYPE_CLASS)
+      break;
+
+    ctx = ctx->parent;
+  }
+
+  bool type_found    = false;
+  fzl_type_t rettype = an_toktotype(analyzer, fn_node->fn.type, &type_found);
+  char *classname    = NULL;
+
+  if (!type_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+             (char *)fn_node->fn.type->value);
+    an_push_error(analyzer, fn_node->fn.type, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (rettype == FZL_TYPE_OBJECT)
+    classname = (char *)fn_node->fn.type->value;
+
+  if (ctx != NULL && ctx->type == FZL_AN_CTX_TYPE_CLASS)
+  {
+    for (size_t i = 0; i < fn_node->fn.args_count; i++)
+    {
+      fzl_node_t *decl = fn_node->fn.args[i];
+      if (decl->type != FZL_NODETYPE_DECLARATION)
+      {
+        an_push_error(analyzer, decl->token, "argument must be a declaration");
+        an_fin_ctx(analyzer);
+        return (fzl_an_res_t){.error = true};
+      }
+
+      char *argname = (char *)decl->var.identifier->token->value;
+      if (strcmp(argname, "this") == 0 && i > 0)
+      {
+        an_push_error(analyzer, decl->token,
+                      "manual declaration of 'this' is not allowed in methods");
+        an_fin_ctx(analyzer);
+        return (fzl_an_res_t){.error = true};
+      }
+    }
+
+    size_t classname_len  = strlen(ctx->classname);
+    size_t methodname_len = strlen((char *)fn_node->fn.name->value);
+    char *methodname      = malloc(classname_len + methodname_len + 2);
+
+    strcpy(methodname, ctx->classname);
+    methodname[classname_len] = '_';
+    strcpy(methodname + classname_len + 1, fn_node->fn.name->value);
+    methodname[classname_len + methodname_len + 1] = 0;
+
+    analyzer->alloc_names[analyzer->alloc_names_top++] = methodname;
+
+    fzl_symtable_res_t putres =
+        fzl_symt_put(analyzer->symbols[ctx->symbols_level - 1], fn_node,
+                     methodname, rettype, 0);
+    if (putres != FZL_SYMTABLE_RESULT_OK)
+    {
+      if (putres == FZL_SYMTABLE_RESULT_EXISTS)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "method '%s.%s' already has been declared", classname,
+                 (char *)fn_node->fn.name->value);
+        an_push_error(analyzer, fn_node->token, an_problem);
+      }
+      else
+        an_push_error(analyzer, fn_node->token, "failed to store method");
+
+      free(analyzer->alloc_names[--analyzer->alloc_names_top]);
+      an_fin_ctx(analyzer);
+      return (fzl_an_res_t){.error = true};
+    }
+    fzl_symt_setobjclass(analyzer->symbols[ctx->symbols_level - 1], methodname,
+                         classname);
+  }
+  else
+  {
+    fzl_symtable_res_t putres =
+        fzl_symt_put(analyzer->symbols[analyzer->symbols_top - 2], fn_node,
+                     (char *)fn_node->fn.name->value, rettype, 0);
+    if (putres != FZL_SYMTABLE_RESULT_OK)
+    {
+      if (putres == FZL_SYMTABLE_RESULT_EXISTS)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "function '%s' already has been declared",
+                 (char *)fn_node->fn.name->value);
+        an_push_error(analyzer, fn_node->token, an_problem);
+      }
+      else
+        an_push_error(analyzer, fn_node->token, "failed to store function");
+
+      free(analyzer->alloc_names[--analyzer->alloc_names_top]);
+      an_fin_ctx(analyzer);
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  fzl_an_res_t body_res = analyze_common(analyzer, fn_node->fn.body);
+  an_fin_ctx(analyzer);
+
+  return (fzl_an_res_t){
+      .error = body_res.error, .type = rettype, .classname = classname};
+}

src/compiler/analyzer/an_identifier.c

@@ -0,0 +1,38 @@
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdio.h>
+
+// Analyze identifier
+fzl_an_res_t analyze_identifier(fzl_analyzer_t *analyzer, fzl_node_t *id)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!id || id->type != FZL_NODETYPE_IDENTIFIER)
+  {
+    an_push_error(analyzer, NULL, "node is not an identifier");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *symname = id->token->value;
+  fzl_sym_t sym;
+  bool sym_found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((sym_found = fzl_symt_get(analyzer->symbols[i], symname, &sym)))
+      break;
+  }
+
+  if (!sym_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "cannot find symbol '%s'",
+             symname);
+    an_push_error(analyzer, id->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = sym.type, .classname = sym.classname};
+}

src/compiler/analyzer/an_loop.c

@@ -0,0 +1,465 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+// Init block analysis result
+typedef struct
+{
+  bool has_var;
+  char *name;
+  fzl_type_t type;
+  char *classname;
+} init_analysis;
+
+// Check init block
+init_analysis check_init(fzl_analyzer_t *analyzer, fzl_node_t *init)
+{
+  if (!analyzer || !init)
+    return (init_analysis){.has_var = false};
+
+  if (init->type == FZL_NODETYPE_IDENTIFIER)
+  {
+    char *name = init->token->value;
+
+    fzl_sym_t sym;
+    bool sym_found = false;
+    for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+    {
+      if ((sym_found = fzl_symt_get(analyzer->symbols[i], name, &sym)))
+        break;
+    }
+
+    if (!sym_found)
+      return (init_analysis){.has_var = false};
+
+    char *classname = NULL;
+    if (sym.type == FZL_TYPE_OBJECT)
+      classname = sym.classname;
+
+    return (init_analysis){.has_var   = true,
+                           .name      = name,
+                           .type      = sym.type,
+                           .classname = classname};
+  }
+  else if (init->type == FZL_NODETYPE_DECLARATION)
+  {
+    char *name = init->var.identifier->token->value;
+
+    bool type_found = false;
+    fzl_type_t type = an_toktotype(analyzer, init->var.type, &type_found);
+    char *classname = NULL;
+
+    if (!type_found)
+    {
+      snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+               (char *)init->var.type->value);
+    }
+
+    if (type == FZL_TYPE_OBJECT)
+      classname = init->var.type->value;
+
+    return (init_analysis){
+        .has_var = true, .name = name, .type = type, .classname = classname};
+  }
+  else if (init->type == FZL_NODETYPE_ASSIGN)
+  {
+    return (init_analysis)check_init(analyzer, init->binary_op.left);
+  }
+
+  return (init_analysis){.has_var = false};
+}
+
+// Condition block analysis result type
+typedef enum
+{
+  COND_TYPE_CONST_TRUE,  // `true` is used as condition
+  COND_TYPE_CONST_FALSE, // `false` is used as condition
+  COND_TYPE_VAR_LESS,    // until variable value is less
+  COND_TYPE_VAR_GREATER, // until variable value is greater
+  COND_TYPE_UNKNOWN,     // cannot determine in compilation time
+} cond_type;
+
+// Condition block analysis result
+typedef struct
+{
+  cond_type type;
+  bool result_bool;
+  char *varname;
+  fzl_type_t vartype;
+  char *classname;
+} cond_analysis;
+
+// Check condition block
+cond_analysis check_condition(fzl_analyzer_t *analyzer, fzl_node_t *cond,
+                              bool report)
+{
+  if (!cond)
+    return (cond_analysis){.type = COND_TYPE_UNKNOWN, .result_bool = false};
+
+  switch (cond->type)
+  {
+    case FZL_NODETYPE_LITERAL:
+      if (cond->token->type == FZL_TOKTYPE_STR_LITERAL)
+      {
+        if (report)
+          an_push_warning(analyzer, cond->token,
+                          "string literal is used as condition");
+        return (cond_analysis){.type = COND_TYPE_UNKNOWN, .result_bool = false};
+      }
+      else if (cond->token->type == FZL_TOKTYPE_NULL_LITERAL)
+      {
+        if (report)
+          an_push_warning(analyzer, cond->token,
+                          "null literal is used as condition");
+        return (cond_analysis){.type = COND_TYPE_UNKNOWN, .result_bool = false};
+      }
+      else if (cond->token->type == FZL_TOKTYPE_BOOL_LITERAL)
+      {
+        if (strcmp(cond->token->value, "true") == 0)
+          return (cond_analysis){.type        = COND_TYPE_CONST_TRUE,
+                                 .result_bool = true};
+        else
+          return (cond_analysis){.type        = COND_TYPE_CONST_FALSE,
+                                 .result_bool = true};
+      }
+      else if (cond->token->type == FZL_TOKTYPE_NUM_LITERAL)
+      {
+        if (strcmp(cond->token->value, "0") == 0)
+          return (cond_analysis){.type        = COND_TYPE_CONST_FALSE,
+                                 .result_bool = false};
+        else
+          return (cond_analysis){.type        = COND_TYPE_CONST_TRUE,
+                                 .result_bool = false};
+      }
+      break;
+
+    case FZL_NODETYPE_LESS:
+    case FZL_NODETYPE_LESS_EQUAL:
+    {
+      fzl_node_t *comp_left    = cond->binary_op.left;
+      cond_analysis left_check = check_condition(analyzer, comp_left, false);
+      if (left_check.varname != NULL)
+        return (cond_analysis){.type        = COND_TYPE_VAR_LESS,
+                               .result_bool = true,
+                               .varname     = left_check.varname,
+                               .vartype     = left_check.vartype,
+                               .classname   = left_check.classname};
+
+      fzl_node_t *comp_right    = cond->binary_op.right;
+      cond_analysis right_check = check_condition(analyzer, comp_right, false);
+      if (right_check.varname != NULL)
+        return (cond_analysis){.type        = COND_TYPE_VAR_GREATER,
+                               .result_bool = true,
+                               .varname     = right_check.varname,
+                               .vartype     = right_check.vartype,
+                               .classname   = right_check.classname};
+
+      return (cond_analysis){.type = COND_TYPE_UNKNOWN};
+    }
+
+    case FZL_NODETYPE_GREATER:
+    case FZL_NODETYPE_GREATER_EQUAL:
+    {
+      fzl_node_t *comp_left    = cond->binary_op.left;
+      cond_analysis left_check = check_condition(analyzer, comp_left, false);
+      if (left_check.varname != NULL)
+        return (cond_analysis){.type        = COND_TYPE_VAR_GREATER,
+                               .result_bool = true,
+                               .varname     = left_check.varname,
+                               .vartype     = left_check.vartype,
+                               .classname   = left_check.classname};
+
+      fzl_node_t *comp_right    = cond->binary_op.right;
+      cond_analysis right_check = check_condition(analyzer, comp_right, false);
+      if (right_check.varname != NULL)
+        return (cond_analysis){.type        = COND_TYPE_VAR_LESS,
+                               .result_bool = true,
+                               .varname     = right_check.varname,
+                               .vartype     = right_check.vartype,
+                               .classname   = right_check.classname};
+
+      return (cond_analysis){.type = COND_TYPE_UNKNOWN};
+    }
+
+    case FZL_NODETYPE_IDENTIFIER:
+    {
+      char *name = cond->token->value;
+      fzl_sym_t sym;
+      bool sym_found = false;
+      for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+      {
+        if ((sym_found = fzl_symt_get(analyzer->symbols[i], name, &sym)))
+          break;
+      }
+
+      if (!sym_found)
+        return (cond_analysis){.type = COND_TYPE_UNKNOWN, .varname = NULL};
+
+      return (cond_analysis){.type      = COND_TYPE_UNKNOWN,
+                             .varname   = name,
+                             .vartype   = sym.type,
+                             .classname = sym.classname};
+    }
+
+    default:
+      break;
+  }
+
+  fzl_an_res_t custom_res = analyze_common(analyzer, cond);
+  if (custom_res.type == FZL_TYPE_BOOL)
+    return (cond_analysis){.type = COND_TYPE_UNKNOWN, .result_bool = true};
+
+  return (cond_analysis){.type = COND_TYPE_UNKNOWN, .result_bool = false};
+}
+
+// Step block change direction
+typedef enum
+{
+  STEP_DIR_TYPE_INCREASE,
+  STEP_DIR_TYPE_DECREASE,
+  STEP_DIR_TYPE_STALL,
+  STEP_DIR_UNKNOWN,
+} step_dir_type;
+
+// Step block analysis
+typedef struct
+{
+  bool changing;
+  char *changing_var;
+  step_dir_type dir;
+} step_analysis;
+
+// Check step block
+step_analysis check_step(fzl_node_t *step)
+{
+  if (!step)
+    return (step_analysis){.changing = false};
+
+  if (step->type == FZL_NODETYPE_ASSIGN)
+  {
+    if (step->binary_op.left->type != FZL_NODETYPE_IDENTIFIER)
+      return (step_analysis){
+          .changing = true, .changing_var = "-", .dir = STEP_DIR_UNKNOWN};
+
+    int dir           = 0;
+    fzl_node_t *right = step->binary_op.right;
+    fzl_node_t *num   = NULL;
+    char *varname     = NULL;
+    if (right->binary_op.left->type != FZL_NODETYPE_IDENTIFIER)
+    {
+      num = right->binary_op.left;
+      if (right->binary_op.right->type == FZL_NODETYPE_IDENTIFIER)
+        varname = right->binary_op.right->token->value;
+    }
+    else
+    {
+      num = right->binary_op.right;
+      if (right->binary_op.left->type == FZL_NODETYPE_IDENTIFIER)
+        varname = right->binary_op.left->token->value;
+    }
+
+    if (right->type == FZL_NODETYPE_ADD || right->type == FZL_NODETYPE_MUL ||
+        right->type == FZL_NODETYPE_POW)
+      dir = 1;
+    else if (right->type == FZL_NODETYPE_SUB ||
+             right->type == FZL_NODETYPE_DIV || right->type == FZL_NODETYPE_MOD)
+      dir = -1;
+
+    if (num && num->type == FZL_NODETYPE_UNARY_MINUS)
+      dir *= -1;
+
+    step_dir_type dirtype = varname == NULL ? STEP_DIR_UNKNOWN
+                            : dir > 0       ? STEP_DIR_TYPE_INCREASE
+                            : dir < 0       ? STEP_DIR_TYPE_DECREASE
+                                            : STEP_DIR_TYPE_STALL;
+
+    return (step_analysis){.changing     = varname != NULL && dir != 0,
+                           .changing_var = varname,
+                           .dir          = dirtype};
+  }
+
+  return (step_analysis){.changing = false, .dir = STEP_DIR_UNKNOWN};
+}
+
+// Body analysis result
+typedef struct
+{
+  bool has_exit;
+} body_analysis;
+
+body_analysis check_body(fzl_node_t *body, bool nested_loop)
+{
+  body_analysis result = {.has_exit = false};
+  switch (body->type)
+  {
+    case FZL_NODETYPE_RETURN:
+      result.has_exit = true;
+      break;
+
+    case FZL_NODETYPE_BREAK:
+      if (!nested_loop)
+        result.has_exit = true;
+      break;
+
+    case FZL_NODETYPE_LOOP:
+      if (body->loop.body)
+      {
+        body_analysis res = check_body(body->loop.body, true);
+        if (res.has_exit)
+          result.has_exit = true;
+      }
+      break;
+
+    case FZL_NODETYPE_CONDITIONAL:
+      if (check_body(body->cond.true_block, nested_loop).has_exit)
+      {
+        result.has_exit = true;
+        break;
+      }
+      break;
+
+    case FZL_NODETYPE_BLOCK:
+      for (size_t i = 0; i < body->list.entry_count; i++)
+      {
+        body_analysis res = check_body(body->list.entries[i], nested_loop);
+        if (res.has_exit)
+        {
+          result.has_exit = true;
+          break;
+        }
+      }
+      break;
+
+    default:
+      break;
+  }
+
+  return result;
+}
+
+// Analyze loop
+fzl_an_res_t analyze_loop(fzl_analyzer_t *analyzer, fzl_node_t *loop_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!loop_node || loop_node->type != FZL_NODETYPE_LOOP)
+  {
+    an_push_error(analyzer, NULL, "node is not typeof LOOP");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_LOOP);
+
+  init_analysis init_data = {
+      .has_var = false, .type = FZL_TYPE_NULL, .name = NULL, .classname = NULL};
+  if (loop_node->loop.init)
+  {
+    fzl_an_res_t init_res = analyze_common(analyzer, loop_node->loop.init);
+    if (init_res.error)
+      return (fzl_an_res_t){.error = true};
+
+    init_data = check_init(analyzer, loop_node->loop.init);
+  }
+
+  cond_analysis cond_data = {.type      = COND_TYPE_CONST_TRUE,
+                             .varname   = NULL,
+                             .vartype   = FZL_TYPE_NULL,
+                             .classname = NULL};
+  if (loop_node->loop.cond)
+  {
+    fzl_an_res_t cond_res = analyze_common(analyzer, loop_node->loop.cond);
+    if (cond_res.error)
+      return (fzl_an_res_t){.error = true};
+
+    cond_data = check_condition(analyzer, loop_node->loop.cond, true);
+
+    if (!cond_data.result_bool && cond_data.type != COND_TYPE_UNKNOWN)
+      an_push_warning(analyzer, loop_node->loop.cond->token,
+                      "resulting type is not boolean");
+
+    if (cond_data.type == COND_TYPE_CONST_FALSE)
+      an_push_warning(analyzer, loop_node->loop.cond->token,
+                      "loop will never execute");
+
+    if (init_data.name && cond_data.varname &&
+        strcmp(init_data.name, cond_data.varname) != 0)
+    {
+      snprintf(an_problem, sizeof(an_problem),
+               "'%s' is used in condition but '%s' is declared. Maybe there is "
+               "mistake?",
+               cond_data.varname, init_data.name);
+      an_push_warning(analyzer, loop_node->loop.cond->token, an_problem);
+    }
+  }
+
+  step_analysis step_data = {
+      .changing = false, .changing_var = NULL, .dir = STEP_DIR_UNKNOWN};
+  if (loop_node->loop.step)
+  {
+    fzl_an_res_t step_res = analyze_common(analyzer, loop_node->loop.step);
+    if (step_res.error)
+      return (fzl_an_res_t){.error = true};
+
+    step_data = check_step(loop_node->loop.step);
+
+    if (step_data.dir != STEP_DIR_UNKNOWN)
+    {
+      if (step_data.changing_var && cond_data.varname &&
+          strcmp(step_data.changing_var, cond_data.varname) != 0)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "changing '%s' but condition checking '%s'",
+                 step_data.changing_var, cond_data.varname);
+        an_push_warning(analyzer, loop_node->loop.step->token, an_problem);
+      }
+
+      if (cond_data.type == COND_TYPE_VAR_GREATER &&
+          step_data.dir == STEP_DIR_TYPE_INCREASE)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "'%s' is increasing while condition is 'greater than'",
+                 step_data.changing_var);
+        an_push_warning(analyzer, loop_node->loop.step->token, an_problem);
+      }
+      else if (cond_data.type == COND_TYPE_VAR_LESS &&
+               step_data.dir == STEP_DIR_TYPE_DECREASE)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "'%s' is decreasing while condition is 'less than'",
+                 step_data.changing_var);
+        an_push_warning(analyzer, loop_node->loop.step->token, an_problem);
+      }
+      else if ((cond_data.type == COND_TYPE_VAR_LESS ||
+                cond_data.type == COND_TYPE_VAR_GREATER) &&
+               step_data.dir == STEP_DIR_TYPE_STALL)
+      {
+        snprintf(an_problem, sizeof(an_problem), "'%s' is stalled",
+                 cond_data.varname);
+        an_push_warning(analyzer, loop_node->loop.step->token, an_problem);
+      }
+    }
+  }
+
+  body_analysis body_data = {.has_exit = false};
+  if (cond_data.type != COND_TYPE_CONST_FALSE)
+  {
+    fzl_an_res_t body_res = analyze_common(analyzer, loop_node->loop.body);
+    if (body_res.error)
+      return (fzl_an_res_t){.error = true};
+
+    body_data = check_body(loop_node->loop.body, false);
+    if (cond_data.type == COND_TYPE_CONST_TRUE && !body_data.has_exit)
+      an_push_warning(analyzer, loop_node->token, "possibly infinite loop");
+  }
+
+  an_fin_ctx(analyzer);
+
+  return (fzl_an_res_t){.error = false, .type = FZL_TYPE_NULL};
+}

src/compiler/analyzer/an_ref.c

@@ -0,0 +1,39 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Analyze reference
+fzl_an_res_t analyze_ref(fzl_analyzer_t *analyzer, fzl_node_t *ref_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!ref_node || ref_node->type != FZL_NODETYPE_REFERENCE)
+  {
+    an_push_error(analyzer, NULL, "node is not a reference");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  char *refto = (char *)ref_node->token->value;
+  fzl_sym_t sym;
+  bool found = false;
+  for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+  {
+    if ((found = fzl_symt_get(analyzer->symbols[i], refto, &sym)))
+      break;
+  }
+
+  if (!found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "cannot find name '%s'", refto);
+    an_push_error(analyzer, ref_node->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_HANDLE, .classname = refto};
+}

src/compiler/analyzer/an_return.c

@@ -0,0 +1,113 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Analyze return statement
+fzl_an_res_t analyze_return(fzl_analyzer_t *analyzer, fzl_node_t *ret_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!ret_node || ret_node->type != FZL_NODETYPE_RETURN)
+  {
+    an_push_error(analyzer, NULL, "node is not a return statement");
+    return (fzl_an_res_t){.error = false};
+  }
+
+  fzl_an_ctx_t *fnctx = analyzer->ctx;
+  while (fnctx != NULL)
+  {
+    if (fnctx->type == FZL_AN_CTX_TYPE_FUNCTION)
+      break;
+
+    fnctx = fnctx->parent;
+  }
+
+  fzl_an_ctx_t *classctx = analyzer->ctx;
+  while (classctx != NULL)
+  {
+    if (classctx && classctx->type == FZL_AN_CTX_TYPE_CLASS)
+      break;
+
+    classctx = classctx->parent;
+  }
+
+  bool is_in_method =
+      classctx != NULL && classctx->type == FZL_AN_CTX_TYPE_CLASS;
+
+  if (!fnctx || fnctx->type != FZL_AN_CTX_TYPE_FUNCTION)
+  {
+    an_push_error(analyzer, ret_node->token,
+                  "cannot use 'return' outside the function");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  bool type_found    = false;
+  fzl_type_t rettype = an_toktotype(analyzer, fnctx->fn->fn.type, &type_found);
+  char *classname    = NULL;
+
+  if (!type_found)
+  {
+    snprintf(an_problem, sizeof(an_problem), "symbol '%s' not found",
+             (char *)fnctx->fn->fn.type->value);
+    an_push_error(analyzer, fnctx->fn->fn.type, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (rettype == FZL_TYPE_OBJECT)
+    classname = (char *)fnctx->fn->fn.type->value;
+
+  char *rettype_str = an_typetostr(rettype, classname);
+  if (rettype != FZL_TYPE_NULL)
+  {
+    if (ret_node->ret.value == NULL)
+    {
+      if (is_in_method)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "cannot return null as method '%s.%s' have return type '%s'",
+                 classctx->classname, (char *)fnctx->fn->fn.name->value,
+                 rettype_str);
+      }
+      else
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "cannot return null as function '%s' have return type '%s'",
+                 (char *)fnctx->fn->fn.name->value, rettype_str);
+      }
+      an_push_error(analyzer, ret_node->token, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+
+    fzl_an_res_t ret_res = analyze_common(analyzer, ret_node->ret.value);
+    if (ret_res.error)
+      return (fzl_an_res_t){.error = true};
+
+    if (!an_is_compatible(ret_res.type, rettype, ret_res.classname, classname))
+    {
+      if (is_in_method)
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "method '%s.%s' is expecting return type '%s', got '%s'",
+                 classctx->classname, (char *)fnctx->fn->fn.name->value,
+                 rettype_str, an_typetostr(ret_res.type, ret_res.classname));
+      }
+      else
+      {
+        snprintf(an_problem, sizeof(an_problem),
+                 "function '%s' is expecting return type '%s', got '%s'",
+                 (char *)fnctx->fn->fn.name->value, rettype_str,
+                 an_typetostr(ret_res.type, ret_res.classname));
+      }
+      an_push_error(analyzer, ret_node->token, an_problem);
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = rettype, .classname = classname};
+}

src/compiler/analyzer/an_strfmt.c

@@ -0,0 +1,39 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stddef.h>
+
+// Analyze format string
+fzl_an_res_t analyze_strfmt(fzl_analyzer_t *analyzer, fzl_node_t *strfmt_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!strfmt_node || strfmt_node->type != FZL_NODETYPE_FMT_STRING)
+  {
+    an_push_error(analyzer, NULL, "node is not format string");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  for (size_t i = 0; i < strfmt_node->list.entry_count; i++)
+  {
+    fzl_node_t *node = strfmt_node->list.entries[i];
+
+    if (node->type != FZL_NODETYPE_LITERAL &&
+        node->type != FZL_NODETYPE_IDENTIFIER)
+    {
+      an_push_error(
+          analyzer, node->token,
+          "format string can only contain string literals and identifiers");
+      return (fzl_an_res_t){.error = true};
+    }
+
+    fzl_an_res_t node_res = analyze_common(analyzer, node);
+    if (node_res.error)
+      return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_STRING, .classname = NULL};
+}

src/compiler/analyzer/an_struct.c

@@ -0,0 +1,56 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+// Analyze structure definition
+fzl_an_res_t analyze_struct(fzl_analyzer_t *analyzer, fzl_node_t *struct_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!struct_node || struct_node->type != FZL_NODETYPE_STRUCT)
+  {
+    an_push_error(analyzer, NULL, "node is not a structure");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_UNNECESSARY);
+
+  if (struct_node->structure.entries_count < 1)
+  {
+    an_push_warning(analyzer, struct_node->token, "empty structure");
+    return (fzl_an_res_t){.error = false};
+  }
+
+  for (size_t i = 0; i < struct_node->structure.entries_count; i++)
+  {
+    fzl_node_t *entry = struct_node->structure.entries[i];
+    if (entry->type != FZL_NODETYPE_DECLARATION &&
+        entry->type != FZL_NODETYPE_IDENTIFIER)
+    {
+      an_push_error(
+          analyzer, entry->token,
+          "structure can contain only declarations and another structures");
+      return (fzl_an_res_t){.error = true};
+    }
+
+    fzl_an_res_t res = analyze_common(analyzer, entry);
+    if (res.error)
+      return (fzl_an_res_t){.error = true};
+
+    if (res.type == FZL_TYPE_OBJECT)
+    {
+      an_push_error(analyzer, entry->token,
+                    "cannot store object inside struct");
+      return (fzl_an_res_t){.error = true};
+    }
+  }
+
+  an_fin_ctx(analyzer);
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_STRUCT, .classname = NULL};
+}

src/compiler/analyzer/an_typedef.c

@@ -0,0 +1,57 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdio.h>
+
+// Analyze type definition
+fzl_an_res_t analyze_typedef(fzl_analyzer_t *analyzer, fzl_node_t *td_node)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!td_node || td_node->type != FZL_NODETYPE_TYPEDEF)
+  {
+    an_push_error(analyzer, NULL, "node is not a type definition");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t res = analyze_common(analyzer, td_node->typedefinition.type);
+  if (res.error)
+    return (fzl_an_res_t){.error = true};
+
+  fzl_nodetype_t type = td_node->typedefinition.type->type;
+  if (type != FZL_NODETYPE_ALIAS && type != FZL_NODETYPE_STRUCT &&
+      type != FZL_NODETYPE_HANDLE && type != FZL_NODETYPE_REFERENCE)
+  {
+    an_push_error(
+        analyzer, td_node->token,
+        "only alias, structure, reference and handle are allowed in type "
+        "definition value");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_symtable_res_t putres =
+      fzl_symt_put(analyzer->symbols[0], td_node,
+                   td_node->typedefinition.typename, res.type, 0);
+  if (putres != FZL_SYMTABLE_RESULT_OK)
+  {
+    if (putres == FZL_SYMTABLE_RESULT_EXISTS)
+      snprintf(an_problem, sizeof(an_problem),
+               "symbol '%s' already has been declared",
+               td_node->typedefinition.typename);
+    else
+      snprintf(an_problem, sizeof(an_problem), "cannot store symbol '%s'",
+               td_node->typedefinition.typename);
+
+    an_push_error(analyzer, td_node->token, an_problem);
+    return (fzl_an_res_t){.error = true};
+  }
+
+  if (res.type == FZL_TYPE_STRUCT || res.type == FZL_TYPE_HANDLE)
+    fzl_symt_setobjclass(analyzer->symbols[0], td_node->typedefinition.typename,
+                         td_node->typedefinition.typename);
+
+  return (fzl_an_res_t){.error = false, .type = res.type, .classname = NULL};
+}

src/compiler/analyzer/an_unarycond.c

@@ -0,0 +1,31 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+
+// Analyze unary condition
+fzl_an_res_t analyze_unarycond(fzl_analyzer_t *analyzer, fzl_node_t *unary)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!unary || unary->type != FZL_NODETYPE_NOT)
+  {
+    an_push_error(analyzer, NULL, "node is not an unary condition operator");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t operand_res = analyze_common(analyzer, unary->unary_op.operand);
+  if (operand_res.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (operand_res.type != FZL_TYPE_BOOL && operand_res.type < FZL_TYPE_INT8)
+  {
+    an_push_error(analyzer, unary->unary_op.operand->token,
+                  "unary condition only support bool and integer types");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+}

src/compiler/analyzer/an_unarymath.c

@@ -0,0 +1,33 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/analyzer.h>
+#include <stdbool.h>
+
+// Analyze unary arithmetic
+fzl_an_res_t analyze_unarymath(fzl_analyzer_t *analyzer, fzl_node_t *unary)
+{
+  if (!analyzer)
+    return (fzl_an_res_t){.error = true};
+
+  if (!unary || (unary->type != FZL_NODETYPE_UNARY_MINUS &&
+                 unary->type != FZL_NODETYPE_UNARY_PLUS))
+  {
+    an_push_error(analyzer, NULL, "node is not an unary math operator");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  fzl_an_res_t operand_res = analyze_common(analyzer, unary->unary_op.operand);
+  if (operand_res.error)
+    return (fzl_an_res_t){.error = true};
+
+  if (operand_res.type < FZL_TYPE_INT8)
+  {
+    an_push_error(analyzer, unary->unary_op.operand->token,
+                  "unary operator only support integer types");
+    return (fzl_an_res_t){.error = true};
+  }
+
+  return (fzl_an_res_t){
+      .error = false, .type = operand_res.type, .classname = NULL};
+}

src/compiler/analyzer/context.c

@@ -0,0 +1,47 @@
+#include <compiler/fzl_analyzer.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Nest context
+fzl_an_ctx_t *an_nest_ctx(fzl_analyzer_t *analyzer, fzl_an_ctx_type_t type)
+{
+  if (!analyzer)
+    return NULL;
+
+  fzl_an_ctx_t *ctx = malloc(sizeof(fzl_an_ctx_t));
+  if (!ctx)
+    return NULL;
+
+  memset(ctx, 0, sizeof(fzl_an_ctx_t));
+
+  ctx->type = type;
+  if (analyzer->ctx != NULL)
+    ctx->parent = analyzer->ctx;
+  else
+    ctx->parent = NULL;
+
+  ctx->symbols                               = fzl_mksymt();
+  ctx->symbols_level                         = analyzer->symbols_top;
+  analyzer->ctx                              = ctx;
+  analyzer->symbols[analyzer->symbols_top++] = ctx->symbols;
+
+  return ctx;
+}
+
+// Close context and return parent
+fzl_an_ctx_t *an_fin_ctx(fzl_analyzer_t *analyzer)
+{
+  if (!analyzer || analyzer->ctx == NULL)
+    return NULL;
+
+  fzl_an_ctx_t *current = analyzer->ctx;
+  fzl_an_ctx_t *parent  = current->parent;
+  analyzer->ctx         = parent;
+
+  free(current);
+  fzl_freesymt(analyzer->symbols[--analyzer->symbols_top]);
+
+  return parent;
+}

src/compiler/analyzer/utility.c

@@ -0,0 +1,160 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+// Check compatibility between A and B types (and classnames)
+bool an_is_compatible(fzl_type_t a, fzl_type_t b, char *ac, char *bc)
+{
+  if (a == b)
+    return true;
+
+  if (a == FZL_TYPE_OBJECT && b == FZL_TYPE_OBJECT)
+  {
+    if (strcmp(ac, "null") == 0 || strcmp(bc, "null") == 0)
+      return true;
+
+    return strcmp(ac, bc) == 0;
+  }
+
+  if (a >= FZL_TYPE_INT8 && b >= FZL_TYPE_INT8)
+    return true;
+
+  return false;
+}
+
+// Convert type to string
+char *an_typetostr(fzl_type_t type, char *classname)
+{
+  if (classname)
+    return classname;
+
+  switch (type)
+  {
+    case FZL_TYPE_NULL:
+      return "null";
+
+    case FZL_TYPE_BOOL:
+      return "boolean";
+
+    case FZL_TYPE_STRING:
+      return "string";
+
+    case FZL_TYPE_CHAR:
+      return "char";
+
+    case FZL_TYPE_INT8:
+      return "i8";
+
+    case FZL_TYPE_INT16:
+      return "i16";
+
+    case FZL_TYPE_INT32:
+      return "i32";
+
+    case FZL_TYPE_INT64:
+      return "i64";
+
+    case FZL_TYPE_UINT8:
+      return "u8";
+
+    case FZL_TYPE_UINT16:
+      return "u16";
+
+    case FZL_TYPE_UINT32:
+      return "u32";
+
+    case FZL_TYPE_UINT64:
+      return "u64";
+
+    case FZL_TYPE_INT:
+      return "int";
+
+    case FZL_TYPE_UINT:
+      return "uint";
+
+    default:
+      return "<unknown>";
+  }
+}
+
+// Convert type token to type
+fzl_type_t an_toktotype(fzl_analyzer_t *analyzer, fzl_token_t *tok,
+                        bool *sym_found)
+{
+  if (!tok)
+    return FZL_TYPE_NULL;
+
+  if (tok->type == FZL_TOKTYPE_NAME)
+  {
+    fzl_sym_t sym;
+    bool found = false;
+    for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
+    {
+      if ((found = fzl_symt_get(analyzer->symbols[i], tok->value, &sym)))
+        break;
+    }
+
+    if (sym_found)
+      *sym_found = found;
+
+    if (found && sym.node->type == FZL_NODETYPE_CLASS)
+      return FZL_TYPE_OBJECT;
+
+    if (found && sym.node->type != FZL_NODETYPE_CLASS &&
+        sym.node->type != FZL_NODETYPE_TYPEDEF)
+    {
+      snprintf(an_problem, sizeof(an_problem), "cannot use '%s' as type",
+               sym.name);
+      an_push_error(analyzer, sym.node->token, an_problem);
+      return FZL_TYPE_NULL;
+    }
+
+    return (found || (tok->value && strcmp(tok->value, "null") == 0))
+               ? sym.type
+               : FZL_TYPE_NULL;
+  }
+
+  if (sym_found)
+    *sym_found = true;
+
+  if (strcmp(tok->value, "null") == 0)
+    return FZL_TYPE_NULL;
+
+  if (strcmp((char *)tok->value, "i8") == 0)
+    return FZL_TYPE_INT8;
+  if (strcmp((char *)tok->value, "i16") == 0)
+    return FZL_TYPE_INT16;
+  if (strcmp((char *)tok->value, "i32") == 0)
+    return FZL_TYPE_INT32;
+  if (strcmp((char *)tok->value, "i64") == 0)
+    return FZL_TYPE_INT64;
+
+  if (strcmp((char *)tok->value, "u8") == 0)
+    return FZL_TYPE_UINT8;
+  if (strcmp((char *)tok->value, "u16") == 0)
+    return FZL_TYPE_UINT16;
+  if (strcmp((char *)tok->value, "u32") == 0)
+    return FZL_TYPE_UINT32;
+  if (strcmp((char *)tok->value, "u64") == 0)
+    return FZL_TYPE_UINT64;
+
+  if (strcmp((char *)tok->value, "int") == 0)
+    return FZL_TYPE_INT;
+  if (strcmp((char *)tok->value, "uint") == 0)
+    return FZL_TYPE_UINT;
+
+  if (strcmp((char *)tok->value, "bool") == 0)
+    return FZL_TYPE_BOOL;
+  if (strcmp((char *)tok->value, "str") == 0)
+    return FZL_TYPE_STRING;
+  if (strcmp((char *)tok->value, "char") == 0)
+    return FZL_TYPE_CHAR;
+
+  return FZL_TYPE_NULL;
+}

src/compiler/fzl_analyzer.c

@@ -0,0 +1,119 @@
+#include <compiler/fzl_analyzer.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/analyzer.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char aerrors[256][256];
+size_t aerrors_top;
+
+char awarnings[256][256];
+size_t awarnings_top;
+
+char an_problem[256];
+
+fzl_analyzer_t *fzl_mkanalyzer(fzl_node_t *node)
+{
+  if (!node)
+    return NULL;
+
+  fzl_analyzer_t *analyzer = malloc(sizeof(fzl_analyzer_t));
+  if (!analyzer)
+    return NULL;
+
+  analyzer->root            = node;
+  analyzer->warnings_top    = 0;
+  analyzer->errors_top      = 0;
+  analyzer->symbols_top     = 0;
+  analyzer->alloc_names_top = 0;
+
+  memset(analyzer->errors, 0, sizeof(analyzer->errors));
+  memset(analyzer->warnings, 0, sizeof(analyzer->warnings));
+  memset(analyzer->symbols, 0, sizeof(analyzer->symbols));
+  memset(analyzer->alloc_names, 0, sizeof(analyzer->alloc_names));
+
+  memset(aerrors, 0, sizeof(aerrors));
+  memset(awarnings, 0, sizeof(awarnings));
+
+  return analyzer;
+}
+
+bool an_push_error(fzl_analyzer_t *analyzer, fzl_token_t *tok, char *error)
+{
+  if (analyzer->errors_top >= 256 || !analyzer || !error)
+    return false;
+
+  size_t ei = aerrors_top++;
+  if (tok != NULL)
+    snprintf(aerrors[ei], sizeof(aerrors[ei]), "'%s':%zu:%zu => %s",
+             tok->filename, tok->ln, tok->cn, error);
+  else
+    snprintf(aerrors[ei], sizeof(aerrors[ei]), "<unknown location> => %s",
+             error);
+
+  analyzer->errors[analyzer->errors_top++] = aerrors[ei];
+  return true;
+}
+
+bool an_push_warning(fzl_analyzer_t *analyzer, fzl_token_t *tok, char *warning)
+{
+  if (analyzer->warnings_top >= 256 || !analyzer || !warning)
+    return false;
+
+  size_t wi = awarnings_top++;
+  if (tok != NULL)
+    snprintf(awarnings[wi], sizeof(awarnings[wi]), "'%s':%zu:%zu => %s",
+             tok->filename, tok->ln, tok->cn, warning);
+  else
+    snprintf(awarnings[wi], sizeof(awarnings[wi]), "<unknown location> => %s",
+             warning);
+
+  analyzer->warnings[analyzer->warnings_top++] = awarnings[wi];
+  return true;
+}
+
+void fzl_analyze(fzl_analyzer_t *analyzer)
+{
+  if (!analyzer)
+    return;
+
+  if (an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_UNNECESSARY) == NULL)
+  {
+    an_push_error(analyzer, NULL, "failed to make global context");
+    return;
+  }
+
+  fzl_node_t *current = analyzer->root;
+  while (current != NULL)
+  {
+    fzl_an_res_t res = analyze_common(analyzer, current);
+    if (res.error)
+      break;
+
+    current = current->next;
+  }
+
+  for (ssize_t i = analyzer->symbols_top; i > 0; i--)
+    an_fin_ctx(analyzer);
+}
+
+void fzl_freeanalyzer(fzl_analyzer_t *analyzer)
+{
+  if (!analyzer)
+    return;
+
+  if (analyzer->alloc_names_top > 0)
+    for (ssize_t i = analyzer->alloc_names_top - 1; i >= 0; i--)
+      free(analyzer->alloc_names[i]);
+
+  memset(analyzer->errors, 0, sizeof(analyzer->errors));
+  memset(analyzer->warnings, 0, sizeof(analyzer->warnings));
+  memset(analyzer->symbols, 0, sizeof(analyzer->symbols));
+  memset(analyzer->alloc_names, 0, sizeof(analyzer->alloc_names));
+  free(analyzer);
+}

src/compiler/fzl_debug.c

@@ -27,10 +27,93 @@ void print_node(fzl_node_t *node, int level)
   if (!node)
     return;
 
+  print_level(levelbuf, level);
   strcpy(printbuf, levelbuf);
 
   switch (node->type)
   {
+    case FZL_NODETYPE_EXTERN:
+      printf("%s Extern bindings to library '%s':\n", levelbuf,
+             node->ext.libname);
+      printf("-%s Types:\n", levelbuf);
+      for (size_t i = 0; i < node->ext.typedefs_count; i++)
+        print_node(node->ext.typedefs[i], level + 2);
+      printf("-%s Functions:\n", levelbuf);
+      for (size_t i = 0; i < node->ext.fns_count; i++)
+        print_node(node->ext.fns[i], level + 2);
+      break;
+
+    case FZL_NODETYPE_EXTERN_FN:
+      printf("%s External function '%s' (original name %s), rettype '%s':\n",
+             levelbuf, node->ext_fn.name, node->ext_fn.original_name,
+             (char *)node->ext_fn.type->value);
+      printf("-%s Arguments:\n", levelbuf);
+      for (size_t i = 0; i < node->ext_fn.args_count; i++)
+        print_node(node->ext_fn.args[i], level + 2);
+      break;
+
+    case FZL_NODETYPE_REFERENCE:
+      printf("%s Reference (pointer type) to '%s'\n", levelbuf,
+             (char *)node->token->value);
+      break;
+
+    case FZL_NODETYPE_STRUCT:
+      printf("%s Structure '%s' (original name %s):\n", levelbuf,
+             (char *)node->token->value, node->structure.original_name);
+      for (size_t i = 0; i < node->structure.entries_count; i++)
+        print_node(node->structure.entries[i], level + 1);
+      break;
+
+    case FZL_NODETYPE_ALIAS:
+      printf("%s Type alias to '%s'\n", levelbuf, (char *)node->token->value);
+      break;
+
+    case FZL_NODETYPE_HANDLE:
+      printf("%s Opaque pointer (handle)\n", levelbuf);
+      break;
+
+    case FZL_NODETYPE_TYPEDEF:
+      printf("%s Type definition '%s':\n", levelbuf,
+             node->typedefinition.typename);
+      print_node(node->typedefinition.type, level + 1);
+      break;
+
+    case FZL_NODETYPE_UNARY_MINUS:
+      printf("%s Unary '-':\n", levelbuf);
+      print_node(node->unary_op.operand, level + 1);
+      break;
+
+    case FZL_NODETYPE_UNARY_PLUS:
+      printf("%s Unary '+':\n", levelbuf);
+      print_node(node->unary_op.operand, level + 1);
+      break;
+
+    case FZL_NODETYPE_BREAK:
+      printf("%s Break\n", levelbuf);
+      break;
+
+    case FZL_NODETYPE_FMT_STRING:
+      printf("%s Format string:\n", levelbuf);
+      for (size_t i = 0; i < node->list.entry_count; i++)
+        print_node(node->list.entries[i], level + 1);
+      break;
+
+    case FZL_NODETYPE_LOOP:
+      printf("%s Loop:\n", levelbuf);
+      printf("-%s Init:\n", levelbuf);
+      if (node->loop.init)
+        print_node(node->loop.init, level + 2);
+      printf("-%s Condition:\n", levelbuf);
+      if (node->loop.cond)
+        print_node(node->loop.cond, level + 2);
+      printf("-%s Step:\n", levelbuf);
+      if (node->loop.step)
+        print_node(node->loop.step, level + 2);
+      printf("-%s Body:\n", levelbuf);
+      if (node->loop.body)
+        print_node(node->loop.body, level + 2);
+      break;
+
     case FZL_NODETYPE_CONSTRUCT:
       printf("%s Construct class '%s':\n", levelbuf,
              (char *)node->construct.name->token->value);
@@ -156,9 +239,6 @@ void print_node(fzl_node_t *node, int level)
     case FZL_NODETYPE_IDENTIFIER:
       printf("%s Identifier ('%s')\n", levelbuf, (char *)node->token->value);
       break;
-
-    default:
-      printf("%s Secure node\n", levelbuf);
   }
 }
 

src/compiler/fzl_gen.c

@@ -0,0 +1,107 @@
+#include <common/fzl_opcodes.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/gen.h>
+#include <compiler/utils/fzl_const_pool.h>
+#include <compiler/utils/fzl_ctable.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+fzl_gen_t *fzl_mkgen(fzl_node_t *root)
+{
+  if (!root)
+    return NULL;
+
+  fzl_gen_t *gen = malloc(sizeof(fzl_gen_t));
+  if (!gen)
+    return NULL;
+
+  memset(gen, 0, sizeof(fzl_gen_t));
+
+  gen->root   = root;
+  gen->consts = fzl_mkconstpool();
+  if (!gen->consts)
+  {
+    free(gen);
+    return NULL;
+  }
+
+  gen->ops_remainder = 2;
+  gen->ops           = malloc(gen->ops_remainder * sizeof(size_t));
+
+  gen->ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_UNECCESSARY, NULL);
+  if (!gen->ctx)
+  {
+    fzl_consts_pool_free(gen->consts);
+    free(gen->ops);
+    free(gen);
+    return NULL;
+  }
+
+  return gen;
+}
+
+bool fzl_gen_run(fzl_gen_t *gen)
+{
+  if (!gen)
+    return false;
+
+  gen_op(gen, FZL_OPCODE_MK_ENVTABLE);
+
+  fzl_node_t *current = gen->root;
+  while (current != NULL)
+  {
+    if (gen_common(gen, current).error)
+      return false;
+
+    current = current->next;
+  }
+
+  gen_op(gen, FZL_OPCODE_RM_ENVTABLE);
+
+  return true;
+}
+
+void fzl_freegen(fzl_gen_t *gen)
+{
+  if (!gen)
+    return;
+
+  if (gen->consts)
+    fzl_consts_pool_free(gen->consts);
+
+  if (gen->ops)
+    free(gen->ops);
+
+  while (gen->ctx != NULL)
+    gen_fin_ctx(gen);
+
+  if (gen->syms_top > 0)
+    for (ssize_t i = gen->syms_top - 1; i >= 0; i--)
+      fzl_freesymt(gen->syms[i]);
+
+  if (gen->classes_count > 0)
+    for (ssize_t i = gen->classes_count - 1; i >= 0; i--)
+      fzl_freectable(gen->classes[i]);
+
+  for (size_t i = 0; i < gen->extern_types_count; i++)
+  {
+    fzl_extern_type_t *type = &gen->extern_types[i];
+    if (type->kind == FZL_EXTERN_KIND_STRUCT)
+      if (type->structure.fields)
+        free(type->structure.fields);
+  }
+
+  for (size_t i = 0; i < gen->extern_fns_count; i++)
+  {
+    fzl_extern_fn_t *fn = &gen->extern_fns[i];
+    if (fn->args)
+      free(fn->args);
+  }
+
+  free(gen);
+}

src/compiler/fzl_reader.c

@@ -1,6 +1,7 @@
-#include "compiler/fzl_token.h"
-#include "compiler/utils/fzl_linked.h"
 #include <compiler/fzl_reader.h>
+#include <compiler/fzl_token.h>
+#include <compiler/internals/reader.h>
+#include <compiler/utils/fzl_linked.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -8,7 +9,7 @@
 #include <string.h>
 
 // Last error from reader
-static char last_err[256] = {0};
+char last_err[256];
 
 fzl_reader_t *fzl_mkreader(fzl_linked_t *linked)
 {
@@ -24,300 +25,99 @@ fzl_reader_t *fzl_mkreader(fzl_linked_t *linked)
   reader->size         = linked->total_sz;
   reader->position     = 0;
 
+  memset(last_err, 0, sizeof(last_err));
+
   return reader;
 }
 
-// --- Read zone ---
-
-// Move cursor forward
-// @deprecated
-static size_t move(fzl_reader_t *reader, size_t len)
-{
-  if (!reader)
-    return 0;
-
-  return reader->position += len;
-}
-
-// Try parse name
-fzl_token_t *parse_name(fzl_reader_t *reader)
-{
-  size_t lpos = reader->position;
-  size_t size = 0;
-
-  do
-  {
-    lpos++;
-    size++;
-  } while ((reader->source[lpos] >= 'A' && reader->source[lpos] <= 'Z') ||
-           (reader->source[lpos] >= 'a' && reader->source[lpos] <= 'z') ||
-           (reader->source[lpos] >= '0' && reader->source[lpos] <= '9') ||
-           (reader->source[lpos] == '_'));
-
-  char *value = malloc(size + 1);
-  memcpy(value, reader->source + reader->position, size);
-  value[size] = '\0';
-
-  size_t start = reader->position;
-  move(reader, size);
-
-  fzl_token_t *tok;
-  fzl_file_loc l;
-  bool ok = fzl_linked_getpos(reader->linked, start, &l);
-  if (!ok)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
-    return NULL;
-  }
-
-  if (strcmp(value, "class") == 0)
-    tok =
-        fzl_mktoken(FZL_TOKTYPE_CLASS, l.line, l.col, value, size, l.filename);
-  else if (strcmp(value, "new") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_NEW, l.line, l.col, value, size, l.filename);
-  else if (strcmp(value, "fn") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_FUNCTION, l.line, l.col, value, size,
-                      l.filename);
-  else if (strcmp(value, "return") == 0)
-    tok =
-        fzl_mktoken(FZL_TOKTYPE_RETURN, l.line, l.col, value, size, l.filename);
-  else if (strcmp(value, "if") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_IF, l.line, l.col, value, size, l.filename);
-  else if (strcmp(value, "else") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_ELSE, l.line, l.col, value, size, l.filename);
-  else if (strcmp(value, "true") == 0 || strcmp(value, "false") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_BOOL_LITERAL, l.line, l.col, value, size,
-                      l.filename);
-  else if (strcmp(value, "null") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_NULL_LITERAL, l.line, l.col, value, size,
-                      l.filename);
-  else if (strcmp(value, "str") == 0 || strcmp(value, "char") == 0 ||
-           strcmp(value, "bool") == 0 || strcmp(value, "uint") == 0 ||
-           strcmp(value, "int") == 0 || strcmp(value, "i8") == 0 ||
-           strcmp(value, "i16") == 0 || strcmp(value, "i32") == 0 ||
-           strcmp(value, "i64") == 0 || strcmp(value, "u8") == 0 ||
-           strcmp(value, "u16") == 0 || strcmp(value, "u32") == 0 ||
-           strcmp(value, "u64") == 0)
-    tok = fzl_mktoken(FZL_TOKTYPE_TYPE, l.line, l.col, value, size, l.filename);
-  else
-    tok = fzl_mktoken(FZL_TOKTYPE_NAME, l.line, l.col, value, size, l.filename);
-  free(value);
-
-  return tok;
-}
-
-// Try parse string literal
-fzl_token_t *parse_string_literal(fzl_reader_t *reader)
-{
-  size_t lpos = reader->position;
-  size_t size = 0;
-
-  if (reader->source[lpos] != '\'' && reader->source[lpos] != '"')
-    return NULL;
-
-  char open_symbol  = reader->source[lpos];
-  char close_symbol = '\0';
-
-  do
-  {
-    lpos++;
-    size++;
-
-    if (reader->source[lpos] == open_symbol)
-      close_symbol = open_symbol;
-
-  } while (reader->source[lpos] != open_symbol && lpos < reader->size);
-  size++;
-
-  fzl_file_loc l;
-  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
-  if (!ok)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
-    return NULL;
-  }
-
-  if (close_symbol != open_symbol)
-  {
-    snprintf(last_err, sizeof(last_err), "'%s': unterminated string at %ld:%ld",
-             l.filename, l.line, l.col);
-    return NULL;
-  }
-
-  if (size == 2)
-  {
-    fzl_token_t *tok =
-        fzl_mktoken(FZL_TOKTYPE_STR_LITERAL, l.line, l.col, "", 0, l.filename);
-    move(reader, 2);
-    return tok;
-  }
-
-  char *value = malloc(size - 2);
-  memcpy(value, reader->source + reader->position + 1, size - 2);
-  fzl_token_t *tok = fzl_mktoken(FZL_TOKTYPE_STR_LITERAL, l.line, l.col, value,
-                                 size - 2, l.filename);
-  free(value);
-  move(reader, size);
-
-  return tok;
-}
-
-// Parse numeric literal
-fzl_token_t *parse_number(fzl_reader_t *reader)
-{
-  if (!reader)
-    return NULL;
-
-  size_t size = 0;
-  size_t lpos = reader->position;
-
-  do
-  {
-    size++;
-    lpos++;
-  } while ((reader->source[lpos] >= '0' && reader->source[lpos] <= '9') &&
-           lpos < reader->size);
-
-  char *value = malloc(size * sizeof(char) + 1);
-  memcpy(value, reader->source + reader->position, size);
-  value[size] = '\0';
-
-  fzl_file_loc l;
-  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
-  if (!ok)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
-    return NULL;
-  }
-
-  fzl_token_t *tok = fzl_mktoken(FZL_TOKTYPE_NUM_LITERAL, l.line, l.col, value,
-                                 size, l.filename);
-  free(value);
-
-  if (!tok)
-    return NULL;
-
-  move(reader, size);
-  return tok;
-}
-
-// Add single-char token
-fzl_token_t *add_single(fzl_reader_t *reader, fzl_toktype_t type)
-{
-  fzl_file_loc l;
-  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
-  if (!ok)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
-    return NULL;
-  }
-
-  move(reader, 1);
-  return fzl_mktoken(type, l.line, l.col, "", 0, l.filename);
-}
-
-// Add double-char token
-fzl_token_t *add_double(fzl_reader_t *reader, fzl_toktype_t type)
-{
-  fzl_file_loc l;
-  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
-  if (!ok)
-  {
-    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
-    return NULL;
-  }
-
-  move(reader, 2);
-  return fzl_mktoken(type, l.line, l.col, "", 0, l.filename);
-}
-
-// Skip symbols until '\n' or EOF
-void skip_comment(fzl_reader_t *reader)
-{
-  move(reader, 2);
-
-  while (reader->position < reader->size)
-  {
-    if (reader->source[reader->position++] == '\n')
-      break;
-  }
-}
-
 int fzl_read(fzl_reader_t *reader)
 {
   if (reader->position >= reader->size)
     return 0;
 
+  bool is_format_str = false;
+
   do
   {
     size_t p = reader->position;
     fzl_token_t *token;
     char curr = reader->source[p];
 
-    if (curr == '\n' || curr == ' ' || curr == '\r')
+    if (is_format_str)
+    {
+      token = rd_fmtstr(reader);
+      if (token && token->type == FZL_TOKTYPE_STR_FORMAT_END)
+        is_format_str = false;
+    }
+    else if (curr == '\n' || curr == ' ' || curr == '\r')
     {
       move(reader, 1);
       continue;
     }
-
+    else if (curr == '\'' || curr == '"')
-    if (curr == '\'' || curr == '"')
+      token = rd_string_literal(reader);
-      token = parse_string_literal(reader);
     else if (curr == '/' && reader->source[p + 1] == '/')
     {
-      skip_comment(reader);
+      rd_comment(reader);
       continue;
     }
     else if (curr == '=' && reader->source[p + 1] == '=')
-      token = add_double(reader, FZL_TOKTYPE_EQEQ);
+      token = rd_double(reader, FZL_TOKTYPE_EQEQ);
     else if (curr == '>' && reader->source[p + 1] == '=')
-      token = add_double(reader, FZL_TOKTYPE_REQ);
+      token = rd_double(reader, FZL_TOKTYPE_REQ);
     else if (curr == '<' && reader->source[p + 1] == '=')
-      token = add_double(reader, FZL_TOKTYPE_LEQ);
+      token = rd_double(reader, FZL_TOKTYPE_LEQ);
     else if (curr == '!' && reader->source[p + 1] == '=')
-      token = add_double(reader, FZL_TOKTYPE_NEQ);
+      token = rd_double(reader, FZL_TOKTYPE_NEQ);
     else if (curr == '|' && reader->source[p + 1] == '|')
-      token = add_double(reader, FZL_TOKTYPE_DVBAR);
+      token = rd_double(reader, FZL_TOKTYPE_DVBAR);
     else if (curr == '&' && reader->source[p + 1] == '&')
-      token = add_double(reader, FZL_TOKTYPE_DAMPERSAND);
+      token = rd_double(reader, FZL_TOKTYPE_DAMPERSAND);
     else if (curr == '>')
-      token = add_single(reader, FZL_TOKTYPE_RANGLE);
+      token = rd_single(reader, FZL_TOKTYPE_RANGLE);
     else if (curr == '<')
-      token = add_single(reader, FZL_TOKTYPE_LANGLE);
+      token = rd_single(reader, FZL_TOKTYPE_LANGLE);
     else if (curr == '!')
-      token = add_single(reader, FZL_TOKTYPE_NOT);
+      token = rd_single(reader, FZL_TOKTYPE_NOT);
     else if (curr == ';')
-      token = add_single(reader, FZL_TOKTYPE_SEMICOLON);
+      token = rd_single(reader, FZL_TOKTYPE_SEMICOLON);
     else if (curr == '{')
-      token = add_single(reader, FZL_TOKTYPE_LBRACE);
+      token = rd_single(reader, FZL_TOKTYPE_LBRACE);
     else if (curr == '}')
-      token = add_single(reader, FZL_TOKTYPE_RBRACE);
+      token = rd_single(reader, FZL_TOKTYPE_RBRACE);
     else if (curr == '(')
-      token = add_single(reader, FZL_TOKTYPE_LPAREN);
+      token = rd_single(reader, FZL_TOKTYPE_LPAREN);
     else if (curr == ')')
-      token = add_single(reader, FZL_TOKTYPE_RPAREN);
+      token = rd_single(reader, FZL_TOKTYPE_RPAREN);
     else if (curr == ',')
-      token = add_single(reader, FZL_TOKTYPE_COMMA);
+      token = rd_single(reader, FZL_TOKTYPE_COMMA);
     else if (curr == '.')
-      token = add_single(reader, FZL_TOKTYPE_DOT);
+      token = rd_single(reader, FZL_TOKTYPE_DOT);
     else if (curr == '*')
-      token = add_single(reader, FZL_TOKTYPE_STAR);
+      token = rd_single(reader, FZL_TOKTYPE_STAR);
     else if (curr == '/')
-      token = add_single(reader, FZL_TOKTYPE_SLASH);
+      token = rd_single(reader, FZL_TOKTYPE_SLASH);
     else if (curr == '+')
-      token = add_single(reader, FZL_TOKTYPE_PLUS);
+      token = rd_single(reader, FZL_TOKTYPE_PLUS);
     else if (curr == '-')
-      token = add_single(reader, FZL_TOKTYPE_MINUS);
+      token = rd_single(reader, FZL_TOKTYPE_MINUS);
     else if (curr == '^')
-      token = add_single(reader, FZL_TOKTYPE_CARET);
+      token = rd_single(reader, FZL_TOKTYPE_CARET);
     else if (curr == '%')
-      token = add_single(reader, FZL_TOKTYPE_PERCENT);
+      token = rd_single(reader, FZL_TOKTYPE_PERCENT);
     else if (curr == '=')
-      token = add_single(reader, FZL_TOKTYPE_EQ);
+      token = rd_single(reader, FZL_TOKTYPE_EQ);
+    else if (curr == '$' && reader->source[p + 1] == '"')
+    {
+      move(reader, 2);
+      is_format_str = true;
+      token = fzl_mktoken(FZL_TOKTYPE_STR_FORMAT_START, 0, 0, NULL, 0, "");
+    }
     else if ((curr >= 'A' && curr <= 'Z') || (curr >= 'a' && curr <= 'z') ||
              curr == '_')
-      token = parse_name(reader);
+      token = rd_name(reader);
     else if (curr >= '0' && curr <= '9')
-      token = parse_number(reader);
+      token = rd_number(reader);
     else
     {
       fzl_file_loc l;
@@ -363,8 +163,6 @@ int fzl_read(fzl_reader_t *reader)
   return 0;
 }
 
-// --- Read zone end ---
-
 char *fzl_reader_geterror() { return last_err; }
 
 void free_node_and_next(fzl_reader_ll_t *node)

src/compiler/fzl_token.c

@@ -30,7 +30,11 @@ fzl_token_t *fzl_mktoken(const fzl_toktype_t type, size_t line, size_t col,
 // Free allocated token
 void fzl_freetoken(fzl_token_t *tok)
 {
-  if (tok->store_value)
+  if (!tok)
+    return;
+
+  if (tok->store_value && tok->value)
     free(tok->value);
+
   free(tok);
 }

src/compiler/fzl_writer.c

@@ -1,4 +1,6 @@
+#include <compiler/fzl_gen.h>
 #include <compiler/fzl_writer.h>
+#include <compiler/internals/writer.h>
 #include <compiler/utils/fzl_const_pool.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -11,52 +13,82 @@ char wrlast_err[256];
 fzl_writer_t *fzl_mkwriter(const char *filepath)
 {
   if (strlen(filepath) < 1)
-    return NULL;
+    return nullptr;
 
   fzl_writer_t *writer = malloc(sizeof(fzl_writer_t));
   if (!writer)
-    return NULL;
+    return nullptr;
 
   writer->filepath = filepath;
 
   return writer;
 }
 
-int fzl_write(fzl_writer_t *writer, fzl_walker_t *walker)
+int fzl_write(fzl_writer_t *writer, fzl_gen_t *gen)
 {
-  if (!writer || !walker)
+  if (!writer || !gen)
     return -1;
 
-  FILE *fp = fopen(writer->filepath, "wb");
+  FILE *fd = fopen(writer->filepath, "wb");
-  if (!fp)
+  if (!fd)
   {
     snprintf(wrlast_err, sizeof(wrlast_err), "failed to open '%s' to write",
              writer->filepath);
     return -1;
   }
 
-  const char hdr[5] = {'F', 'Z', 'L', 0x0, 0x1};
+  constexpr char hdr[5] = {'F', 'Z', 'L', 0x0, 0x2};
-  fwrite(hdr, sizeof(char), 5, fp);
+  fwrite(hdr, sizeof(char), 5, fd);
-  fwrite(&walker->consts->size, sizeof(size_t), 1, fp);
+  fwrite(&gen->consts->size, sizeof(uint16_t), 1, fd);
-  fwrite(&walker->op_count, sizeof(size_t), 1, fp);
+  fwrite(&gen->extern_libs_count, sizeof(uint16_t), 1, fd);
+  fwrite(&gen->extern_types_count, sizeof(uint16_t), 1, fd);
+  fwrite(&gen->extern_fns_count, sizeof(uint16_t), 1, fd);
+  fwrite(&gen->ops_count, sizeof(size_t), 1, fd);
 
-  for (size_t i = 0; i < walker->consts->size; i++)
+  bool result = wr_consts(fd, gen->consts);
+  if (!result)
   {
-    fzl_const_t c = walker->consts->array[i];
+    snprintf(wrlast_err, sizeof(wrlast_err), "failed to write constants table");
-    fwrite(&c.type, sizeof(fzl_consttype_t), 1, fp);
+    fclose(fd);
-
+    return -1;
-    if (c.type == FZL_CONSTTYPE_STRING)
-    {
-      size_t strlen = c.as.string.length;
-      fwrite(&c.as.string.length, sizeof(size_t), 1, fp);
-      fwrite(c.as.string.chars, sizeof(char), strlen, fp);
-    }
   }
 
-  if (walker->op_count > 0)
+  result = wr_extern_libs(fd, gen->extern_libs, gen->extern_libs_count);
-    fwrite(walker->ops, sizeof(uint64_t), walker->op_count, fp);
+  if (!result)
+  {
+    snprintf(wrlast_err, sizeof(wrlast_err),
+             "failed to write external lib names");
+    fclose(fd);
+    return -1;
+  }
 
-  fclose(fp);
+  result = wr_extern_types(fd, gen->extern_types, gen->extern_types_count);
+  if (!result)
+  {
+    snprintf(wrlast_err, sizeof(wrlast_err),
+             "failed to write extern lib types");
+    fclose(fd);
+    return -1;
+  }
+
+  result = wr_extern_fns(fd, gen->extern_fns, gen->extern_fns_count);
+  if (!result)
+  {
+    snprintf(wrlast_err, sizeof(wrlast_err),
+             "failed to write extern lib functions");
+    fclose(fd);
+    return -1;
+  }
+
+  result = wr_ops(fd, gen->ops, gen->ops_count);
+  if (!result)
+  {
+    snprintf(wrlast_err, sizeof(wrlast_err), "failed to write opcodes");
+    fclose(fd);
+    return -1;
+  }
+
+  fclose(fd);
 
   return 0;
 }

src/compiler/generator/context.c

@@ -0,0 +1,84 @@
+#include "compiler/fzl_parser.h"
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Nest context
+fzl_gen_ctx_t *gen_ctx(fzl_gen_t *gen, fzl_gen_ctx_type_t type,
+                       fzl_node_t *node)
+{
+  if (!gen)
+    return NULL;
+
+  fzl_gen_ctx_t *ctx = malloc(sizeof(fzl_gen_ctx_t));
+  if (!ctx)
+    return NULL;
+
+  memset(ctx, 0, sizeof(fzl_gen_ctx_t));
+  ctx->type = type;
+
+  if (ctx->type != FZL_GEN_CTX_TYPE_CLASS)
+  {
+    fzl_symtable_t *symt = fzl_mksymt();
+    if (!symt)
+    {
+      free(ctx);
+      return NULL;
+    }
+
+    gen->syms[gen->syms_top++] = symt;
+  }
+
+  size_t level          = 0;
+  fzl_gen_ctx_t *parent = gen->ctx;
+  while (parent != NULL)
+  {
+    level++;
+    parent = parent->parent;
+  }
+
+  ctx->level  = level;
+  ctx->parent = gen->ctx;
+
+  if (type == FZL_GEN_CTX_TYPE_FUNCTION)
+  {
+    if (node->type == FZL_NODETYPE_FUNCTION ||
+        node->type == FZL_NODETYPE_EXTERN_FN)
+      ctx->function = node;
+    else
+    {
+      fzl_freesymt(gen->syms[--gen->syms_top]);
+      free(ctx);
+      return NULL;
+    }
+  }
+
+  gen->ctx = ctx;
+
+  return gen->ctx;
+}
+
+fzl_gen_ctx_t *gen_fin_ctx(fzl_gen_t *gen)
+{
+  if (!gen)
+    return NULL;
+
+  fzl_gen_ctx_t *ctx = gen->ctx;
+  if (!ctx)
+    return NULL;
+
+  if (ctx->type != FZL_GEN_CTX_TYPE_CLASS)
+  {
+    fzl_symtable_t *sym = gen->syms[--gen->syms_top];
+    if (sym)
+      fzl_freesymt(sym);
+  }
+
+  gen->ctx = ctx->parent;
+  free(ctx);
+
+  return gen->ctx;
+}

src/compiler/generator/gen_alias.c

@@ -0,0 +1,31 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+char alias_typecn[256];
+
+// Type aliasing
+gen_res_t gen_alias(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_type_t type;
+  memset(alias_typecn, 0, sizeof(alias_typecn));
+
+  bool resolved = gen_resolve_type(gen, node->token, &type, alias_typecn);
+  if (!resolved)
+    return gen_error;
+
+  ssize_t slot = gen_resolve_extern_type(gen, alias_typecn);
+  if (slot == -1)
+    type_buf.alias_target =
+        (fzl_extern_type_ref_t){.is_primitive = true, .primitive = type};
+  else
+    type_buf.alias_target =
+        (fzl_extern_type_ref_t){.is_primitive = false, .type_slot = slot};
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_assign.c

@@ -0,0 +1,122 @@
+#include <compiler/fzl_gen.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/gen.h>
+#include <string.h>
+
+// Assignment to declaration
+gen_res_t assign_declaration(fzl_gen_t *gen, fzl_node_t *node)
+{
+  gen_res_t rres = gen_common(gen, node->binary_op.right);
+  if (rres.error)
+    return gen_error;
+
+  gen_res_t lres = gen_common(gen, node->binary_op.left);
+  if (lres.error)
+    return gen_error;
+
+  if (!gen_is_types_compatible(rres.type, lres.type, rres.classname,
+                               lres.classname))
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_WRITE);
+
+  return (gen_res_t){
+      .error = false, .type = rres.type, .classname = rres.classname};
+}
+
+// Assignment to identifier
+gen_res_t assign_id(fzl_gen_t *gen, fzl_node_t *node)
+{
+  gen_res_t rres = gen_common(gen, node->binary_op.right);
+  if (rres.error)
+    return gen_error;
+
+  char *name = (char *)node->binary_op.left->token->value;
+  fzl_sym_t sym;
+  bool found = false;
+  ssize_t i  = gen->syms_top - 1;
+  for (; i >= 0; i--)
+    if ((found = fzl_symt_get(gen->syms[i], name, &sym)))
+      break;
+
+  if (!found)
+    return gen_error;
+
+  if (!gen_is_types_compatible(sym.type, rres.type, sym.classname,
+                               rres.classname))
+    return gen_error;
+
+  if (!sym.slot_set)
+    return gen_error;
+
+  size_t depth = gen->syms_top - 1 - i;
+  gen_op(gen, FZL_OPCODE_STORE_LOCAL);
+  gen_word(gen, depth);
+  gen_word(gen, sym.slot);
+
+  return (gen_res_t){
+      .error = false, .type = rres.type, .classname = rres.classname};
+}
+
+// Assignment to field
+gen_res_t assign_field(fzl_gen_t *gen, fzl_node_t *node)
+{
+  gen_res_t rres = gen_common(gen, node->binary_op.right);
+  if (rres.error)
+    return gen_error;
+
+  fzl_node_t *field_node = node->binary_op.left;
+  gen_res_t obj_res      = gen_common(gen, field_node->memb.parent);
+  if (obj_res.error)
+    return gen_error;
+
+  fzl_ctable_t *ct = NULL;
+  for (size_t i = 0; i < gen->classes_count; i++)
+  {
+    if (strcmp(obj_res.classname, gen->classes[i]->name) == 0)
+    {
+      ct = gen->classes[i];
+      break;
+    }
+  }
+
+  if (!ct)
+    return gen_error;
+
+  fzl_ctable_field_t *ctf = NULL;
+  for (size_t i = 0; i < ct->fields_count; i++)
+  {
+    if (strcmp(field_node->memb.field->token->value, ct->fields[i].name) == 0)
+    {
+      ctf = &ct->fields[i];
+      break;
+    }
+  }
+
+  if (!ctf)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_SET_FIELD);
+  gen_word(gen, ctf->slot_index);
+
+  return (gen_res_t){
+      .error = false, .type = rres.type, .classname = rres.classname};
+}
+
+// Assignment
+gen_res_t gen_assign(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  if (node->binary_op.left->type == FZL_NODETYPE_DECLARATION)
+    return assign_declaration(gen, node);
+
+  if (node->binary_op.left->type == FZL_NODETYPE_IDENTIFIER)
+    return assign_id(gen, node);
+
+  if (node->binary_op.left->type == FZL_NODETYPE_FIELD)
+    return assign_field(gen, node);
+
+  return gen_error;
+}

src/compiler/generator/gen_block.c

@@ -0,0 +1,27 @@
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+
+// Block definition
+gen_res_t gen_block(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_gen_ctx_t *ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_UNECCESSARY, node);
+  if (!ctx)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_MK_ENVTABLE);
+  if (node->list.entry_count > 0)
+    for (size_t i = 0; i < node->list.entry_count; i++)
+      if (gen_common(gen, node->list.entries[i]).error)
+        return gen_error;
+
+  ctx = gen_fin_ctx(gen);
+  if (!ctx)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_RM_ENVTABLE);
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_break.c

@@ -0,0 +1,33 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Break keyword
+gen_res_t gen_break(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_gen_ctx_t *ctx = gen->ctx;
+  while (ctx != NULL)
+  {
+    if (ctx && ctx->type == FZL_GEN_CTX_TYPE_LOOP)
+      break;
+
+    ctx = ctx->parent;
+  }
+
+  if (!ctx || ctx->type != FZL_GEN_CTX_TYPE_LOOP)
+    return gen_error;
+
+  for (size_t i = gen->syms_top - 1; i > ctx->level + 1; i--)
+    gen_op(gen, FZL_OPCODE_RM_ENVTABLE);
+
+  gen_op(gen, FZL_OPCODE_JMP);
+  ctx->loop.breaks[ctx->loop.breaks_count++] = gen->ops_count;
+  gen_word(gen, 0);
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_call.c

@@ -0,0 +1,230 @@
+#include <common/fzl_builtins.h>
+#include <common/fzl_extern.h>
+#include <common/fzl_opcodes.h>
+#include <common/fzl_types.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Call definition
+// NOTE: split by call type (builtin/declared/extern)
+gen_res_t gen_call(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  // `printline(x)` builtin function
+  if (strcmp(node->token->value, "printline") == 0)
+  {
+    if (node->call.args_count > 0)
+      for (size_t i = 0; i < node->call.args_count; i++)
+        if (gen_common(gen, node->call.args[i]).error)
+          return gen_error;
+
+    gen_op(gen, FZL_OPCODE_CALL_BUILTIN);
+    gen_word(gen, FZL_BUILTIN_PRINTLINE);
+    if (node->call.args_count < 1)
+      return gen_error;
+
+    return gen_ok_null;
+  }
+
+  // `exit(x?)` builtin function
+  if (strcmp(node->token->value, "exit") == 0)
+  {
+    if (node->call.args_count > 0)
+    {
+      for (size_t i = 0; i < node->call.args_count; i++)
+        if (gen_common(gen, node->call.args[i]).error)
+          return gen_error;
+
+      gen_op(gen, FZL_OPCODE_CALL_BUILTIN);
+      gen_word(gen, FZL_BUILTIN_EXIT);
+      if (node->call.args_count < 1)
+        return gen_error;
+    }
+
+    return gen_ok_null;
+  }
+
+  if (node->call.callee->type == FZL_NODETYPE_IDENTIFIER)
+  {
+    if (node->call.args_count > 0)
+      for (size_t i = 0; i < node->call.args_count; i++)
+        if (gen_common(gen, node->call.args[i]).error)
+          return gen_error;
+
+    char *name = (char *)node->token->value;
+    fzl_sym_t sym;
+    bool found = gen_resolve_name(gen, name, &sym);
+    if (!found)
+      return gen_error;
+
+    if (sym.node->type == FZL_NODETYPE_EXTERN_FN)
+    {
+      size_t fn_n         = 0;
+      fzl_extern_fn_t *fn = NULL;
+      for (size_t i = 0; i < gen->extern_fns_count; i++)
+      {
+        if (strcmp(gen->extern_fns[i].used_name, name) == 0)
+        {
+          fn   = &gen->extern_fns[i];
+          fn_n = i;
+          break;
+        }
+      }
+
+      if (!fn)
+        return gen_error;
+
+      fzl_type_t rettype;
+      char *rettypecn = NULL;
+
+      if (!fn->has_return)
+      {
+        rettype = FZL_TYPE_NULL;
+      }
+      else if (fn->ret_type.is_primitive)
+      {
+        rettype = fn->ret_type.primitive;
+      }
+      else
+      {
+        fzl_extern_type_t *type = &gen->extern_types[fn->ret_type.type_slot];
+        switch (type->kind)
+        {
+          case FZL_EXTERN_KIND_REF:
+            rettype   = FZL_TYPE_HANDLE;
+            rettypecn = type->name;
+            break;
+
+          case FZL_EXTERN_KIND_STRUCT:
+            rettype   = FZL_TYPE_STRUCT;
+            rettypecn = type->name;
+            break;
+
+          case FZL_EXTERN_KIND_HANDLE:
+            rettype   = FZL_TYPE_HANDLE;
+            rettypecn = type->name;
+            break;
+
+          case FZL_EXTERN_KIND_ALIAS:
+            if (type->alias_target.is_primitive)
+            {
+              rettype = type->alias_target.primitive;
+            }
+            else
+            {
+              fzl_extern_type_t *aliased =
+                  &gen->extern_types[type->alias_target.type_slot];
+              switch (aliased->kind)
+              {
+                case FZL_EXTERN_KIND_ALIAS:
+                  return gen_error;
+
+                case FZL_EXTERN_KIND_HANDLE:
+                  rettype   = FZL_TYPE_HANDLE;
+                  rettypecn = aliased->name;
+                  break;
+
+                case FZL_EXTERN_KIND_STRUCT:
+                  rettype   = FZL_TYPE_STRUCT;
+                  rettypecn = aliased->name;
+                  break;
+
+                case FZL_EXTERN_KIND_REF:
+                  rettype   = FZL_TYPE_HANDLE;
+                  rettypecn = aliased->name;
+                  break;
+
+                default:
+                  return gen_error;
+              }
+            }
+            break;
+
+          default:
+            return gen_error;
+        }
+      }
+
+      gen_op(gen, FZL_OPCODE_CALL_EXTERN);
+      gen_word(gen, fn_n);
+
+      return (gen_res_t){
+          .error = false, .type = rettype, .classname = rettypecn};
+    }
+    else
+    {
+      if (!sym.ip)
+        return gen_error;
+
+      gen_op(gen, FZL_OPCODE_CALL);
+      gen_word(gen, sym.ip);
+
+      return (gen_res_t){
+          .error = false, .type = sym.type, .classname = sym.classname};
+    }
+  }
+
+  if (node->call.callee->type == FZL_NODETYPE_FIELD)
+  {
+    fzl_node_t *parent_node = node->call.callee->memb.parent;
+    fzl_node_t *method_node = node->call.callee->memb.field;
+
+    gen_res_t parent_res = gen_common(gen, parent_node);
+    if (parent_res.error)
+      return gen_error;
+
+    if (parent_res.type != FZL_TYPE_OBJECT || !parent_res.classname)
+      return gen_error;
+
+    char *classname   = parent_res.classname;
+    bool class_exists = false;
+    for (size_t i = 0; i < gen->classes_count; i++)
+    {
+      if (strcmp(classname, gen->classes[i]->name) == 0)
+      {
+        class_exists = true;
+        break;
+      }
+    }
+
+    if (!class_exists)
+      return gen_error;
+
+    size_t classlen  = strlen(classname);
+    size_t fnlen     = strlen(method_node->token->value);
+    char *methodname = malloc(classlen + fnlen + 2);
+    strcpy(methodname, classname);
+    strcpy((methodname + classlen + 1), method_node->token->value);
+    methodname[classlen]             = '_';
+    methodname[classlen + fnlen + 1] = 0;
+
+    fzl_sym_t fn_sym;
+    bool found_method = false;
+    for (ssize_t i = gen->syms_top - 1; i >= 0; i--)
+      if ((found_method = fzl_symt_get(gen->syms[i], methodname, &fn_sym)))
+        break;
+
+    free(methodname);
+    if (!found_method)
+      return gen_error;
+
+    if (node->call.args_count > 0)
+      for (size_t i = 0; i < node->call.args_count; i++)
+        if (gen_common(gen, node->call.args[i]).error)
+          return gen_error;
+
+    gen_op(gen, FZL_OPCODE_CALL);
+    gen_word(gen, fn_sym.ip);
+
+    return (gen_res_t){
+        .error = false, .type = fn_sym.type, .classname = fn_sym.classname};
+  }
+
+  return gen_error;
+}

src/compiler/generator/gen_class.c

@@ -0,0 +1,79 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char class_typecn[256];
+
+// Class definition
+gen_res_t gen_class(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_gen_ctx_t *ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_CLASS, node);
+  if (!ctx)
+    return gen_error;
+
+  gen->classes[gen->classes_count] = fzl_mkctable(node->class.name->value);
+  fzl_ctable_t *class              = gen->classes[gen->classes_count++];
+  class->name                      = (char *)node->class.name->value;
+
+  for (size_t i = 0; i < node->class.fields_count; i++)
+  {
+    if (class->fields_remainder <= class->fields_count)
+    {
+      class->fields_remainder *= 2;
+      class->fields = realloc(class->fields, class->fields_remainder *
+                                                 sizeof(fzl_ctable_field_t));
+    }
+
+    fzl_type_t type;
+    memset(class_typecn, 0, sizeof(class_typecn));
+
+    bool resolved = gen_resolve_type(gen, node->class.fields[i]->var.type,
+                                     &type, class_typecn);
+    if (!resolved)
+      return gen_error;
+
+    class->fields[class->fields_count] = (fzl_ctable_field_t){
+        .name       = node->class.fields[i]->var.identifier->token->value,
+        .type       = type,
+        .slot_index = class->fields_count++};
+  }
+
+  for (size_t i = 0; i < node->class.methods_count; i++)
+  {
+    fzl_node_t *fn = node->class.methods[i];
+
+    size_t classname_len = strlen(class->name);
+    size_t fnname_len    = strlen(fn->fn.name->value);
+    char *method_name    = malloc(classname_len + fnname_len + 2);
+
+    strcpy(method_name, class->name);
+    method_name[classname_len] = '_';
+    strcpy((method_name + classname_len + 1), fn->fn.name->value);
+    method_name[classname_len + fnname_len + 1] = 0;
+
+    if (fn->fn.name->value)
+      free(fn->fn.name->value);
+
+    fn->fn.name->value = method_name;
+    if (gen_common(gen, fn).error)
+    {
+      free(method_name);
+      fn->fn.name->value = NULL;
+      return gen_error;
+    }
+  }
+
+  ctx = gen_fin_ctx(gen);
+  if (!ctx)
+    return gen_error;
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_common.c

@@ -0,0 +1,154 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+typedef gen_res_t (*gen_handle_fn)(fzl_gen_t *, fzl_node_t *);
+
+char *null_name = "<null>";
+
+gen_res_t gen_error = (gen_res_t){.error = true};
+gen_res_t gen_ok_null =
+    (gen_res_t){.error = false, .type = FZL_TYPE_NULL, .classname = NULL};
+
+// Common generator entry point
+gen_res_t gen_common(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_handle_fn res = NULL;
+  switch (node->type)
+  {
+    case FZL_NODETYPE_ASSIGN:
+      res = gen_assign;
+      break;
+
+    case FZL_NODETYPE_DECLARATION:
+      res = gen_declaration;
+      break;
+
+    case FZL_NODETYPE_NOT:
+      res = gen_unary_logical;
+      break;
+
+    case FZL_NODETYPE_EQUAL:
+    case FZL_NODETYPE_NEQUAL:
+    case FZL_NODETYPE_LESS:
+    case FZL_NODETYPE_LESS_EQUAL:
+    case FZL_NODETYPE_GREATER:
+    case FZL_NODETYPE_GREATER_EQUAL:
+      res = gen_compare;
+      break;
+
+    case FZL_NODETYPE_OR:
+    case FZL_NODETYPE_AND:
+      res = gen_logical;
+      break;
+
+    case FZL_NODETYPE_UNARY_PLUS:
+    case FZL_NODETYPE_UNARY_MINUS:
+      res = gen_unary_math;
+      break;
+
+    case FZL_NODETYPE_ADD:
+    case FZL_NODETYPE_SUB:
+    case FZL_NODETYPE_MUL:
+    case FZL_NODETYPE_DIV:
+    case FZL_NODETYPE_POW:
+    case FZL_NODETYPE_MOD:
+      res = gen_math;
+      break;
+
+    case FZL_NODETYPE_BREAK:
+      res = gen_break;
+      break;
+
+    case FZL_NODETYPE_LOOP:
+      res = gen_loop;
+      break;
+
+    case FZL_NODETYPE_CONSTRUCT:
+      res = gen_construct;
+      break;
+
+    case FZL_NODETYPE_FIELD:
+      res = gen_field;
+      break;
+
+    case FZL_NODETYPE_CLASS:
+      res = gen_class;
+      break;
+
+    case FZL_NODETYPE_CALL:
+      res = gen_call;
+      break;
+
+    case FZL_NODETYPE_RETURN:
+      res = gen_return;
+      break;
+
+    case FZL_NODETYPE_FUNCTION:
+      res = gen_fn;
+      break;
+
+    case FZL_NODETYPE_CONDITIONAL:
+      res = gen_condition;
+      break;
+
+    case FZL_NODETYPE_IDENTIFIER:
+      res = gen_identifier;
+      break;
+
+    case FZL_NODETYPE_FMT_STRING:
+      res = gen_fmtstr;
+      break;
+
+    case FZL_NODETYPE_LITERAL:
+      res = gen_literal;
+      break;
+
+    case FZL_NODETYPE_BLOCK:
+      res = gen_block;
+      break;
+
+    case FZL_NODETYPE_EXTERN:
+      res = gen_extern;
+      break;
+
+    case FZL_NODETYPE_TYPEDEF:
+      res = gen_typedef;
+      break;
+
+    case FZL_NODETYPE_HANDLE:
+      res = gen_handle;
+      break;
+
+    case FZL_NODETYPE_ALIAS:
+      res = gen_alias;
+      break;
+
+    case FZL_NODETYPE_STRUCT:
+      res = gen_struct;
+      break;
+
+    case FZL_NODETYPE_REFERENCE:
+      res = gen_reference;
+      break;
+
+    case FZL_NODETYPE_EXTERN_FN:
+      res = gen_externfn;
+      break;
+  }
+
+  if (!res)
+  {
+    printf("Bruh, you, suka, go fix the generator blyat (%s:%d)\n", __FILE__,
+           __LINE__);
+    return gen_error;
+  }
+
+  return res(gen, node);
+}

src/compiler/generator/gen_compare.c

@@ -0,0 +1,83 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdio.h>
+
+// Comparison operations
+gen_res_t gen_compare(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_res_t left = gen_common(gen, node->binary_op.left);
+  if (left.error)
+    return left;
+
+  gen_res_t right = gen_common(gen, node->binary_op.right);
+  if (right.error)
+    return right;
+
+  if (!gen_is_types_compatible(left.type, right.type, left.classname,
+                               right.classname))
+    return gen_error;
+
+  if (left.type == FZL_TYPE_STRING && right.type == FZL_TYPE_STRING)
+  {
+    switch (node->type)
+    {
+      case FZL_NODETYPE_EQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_EQ_STR);
+        break;
+
+      case FZL_NODETYPE_NEQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_NEQ_STR);
+        break;
+
+      default:
+        return gen_error;
+    }
+  }
+  else if (left.type == FZL_TYPE_OBJECT && right.type == FZL_TYPE_OBJECT)
+  {
+    switch (node->type)
+    {
+      case FZL_NODETYPE_EQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_EQ_OBJ);
+        break;
+
+      case FZL_NODETYPE_NEQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_NEQ_OBJ);
+        break;
+
+      default:
+        return gen_error;
+    }
+  }
+  else
+  {
+    switch (node->type)
+    {
+      case FZL_NODETYPE_EQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_EQ);
+        break;
+      case FZL_NODETYPE_NEQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_NEQ);
+        break;
+      case FZL_NODETYPE_LESS:
+        gen_op(gen, FZL_OPCODE_CMP_LT);
+        break;
+      case FZL_NODETYPE_LESS_EQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_LTEQ);
+        break;
+      case FZL_NODETYPE_GREATER:
+        gen_op(gen, FZL_OPCODE_CMP_GT);
+        break;
+      case FZL_NODETYPE_GREATER_EQUAL:
+        gen_op(gen, FZL_OPCODE_CMP_GTEQ);
+        break;
+      default:
+        break;
+    }
+  }
+
+  return (gen_res_t){.error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+}

src/compiler/generator/gen_condition.c

@@ -0,0 +1,37 @@
+#include <compiler/internals/gen.h>
+
+// Conditional operation
+gen_res_t gen_condition(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_res_t cres = gen_common(gen, node->cond.condition);
+  if (cres.error)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_JZ);
+
+  size_t jz_if = gen->ops_count;
+  gen_word(gen, (uint64_t)0);
+
+  gen_res_t tblock_res = gen_common(gen, node->cond.true_block);
+  if (tblock_res.error)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_JMP);
+  size_t jmp_else = gen->ops_count;
+  gen_word(gen, (uint64_t)0);
+
+  gen->ops[jz_if] = gen->ops_count;
+
+  if (node->cond.else_block)
+  {
+    gen_res_t fblock_res = gen_common(gen, node->cond.else_block);
+    if (fblock_res.error)
+      return gen_error;
+  }
+
+  gen->ops[jmp_else] = gen->ops_count;
+  return gen_ok_null;
+}

src/compiler/generator/gen_construct.c

@@ -0,0 +1,30 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <string.h>
+
+// Object constructing
+gen_res_t gen_construct(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_node_t *classname = node->construct.name;
+  fzl_ctable_t *ct      = NULL;
+  for (size_t i = 0; i < gen->classes_count; i++)
+  {
+    if (strcmp((char *)classname->token->value, gen->classes[i]->name) == 0)
+    {
+      ct = gen->classes[i];
+      break;
+    }
+  }
+  if (!ct)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_ALLOC_OBJECT);
+  gen_word(gen, ct->fields_count);
+
+  return (gen_res_t){
+      .error = false, .type = FZL_TYPE_OBJECT, .classname = ct->name};
+}

src/compiler/generator/gen_declaration.c

@@ -0,0 +1,61 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <string.h>
+
+char dec_typecn[256];
+
+// Variable (or argument) declaration
+gen_res_t gen_declaration(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  char *name = (char *)node->var.identifier->token->value;
+  fzl_type_t type;
+  memset(dec_typecn, 0, sizeof(dec_typecn));
+
+  bool resolved = gen_resolve_type(gen, node->var.type, &type, dec_typecn);
+  if (!resolved)
+    return gen_error;
+
+  fzl_ctable_t *ct = NULL;
+  if (type == FZL_TYPE_OBJECT)
+  {
+    for (size_t i = 0; i < gen->classes_count; i++)
+    {
+      if (strcmp(node->var.type->value, gen->classes[i]->name) == 0)
+      {
+        ct = gen->classes[i];
+        break;
+      }
+    }
+  }
+
+  fzl_symtable_res_t res =
+      fzl_symt_put(gen->syms[gen->syms_top - 1], node, name, type, 0);
+
+  if (ct)
+    fzl_symt_setobjclass(gen->syms[gen->syms_top - 1], name, ct->name);
+
+  if (res != FZL_SYMTABLE_RESULT_OK)
+    return gen_error;
+
+  if (fzl_symt_setslot(gen->syms[gen->syms_top - 1], name) < 0)
+    return gen_error;
+
+  fzl_token_t *id_tok = node->var.identifier->token;
+  size_t const_n =
+      gen_add_const(gen, (fzl_const_t){.type             = FZL_CONSTTYPE_STRING,
+                                       .as.string.chars  = id_tok->value,
+                                       .as.string.length = id_tok->value_sz});
+
+  gen_op(gen, FZL_OPCODE_LOADCONST);
+  gen_word(gen, const_n);
+
+  gen_op(gen, FZL_OPCODE_STORE);
+  gen_op(gen, FZL_OPCODE_LOADCONST);
+  gen_word(gen, const_n);
+
+  return (gen_res_t){.error = false, .type = type, .classname = dec_typecn};
+}

src/compiler/generator/gen_extern.c

@@ -0,0 +1,26 @@
+#include <common/fzl_extern.h>
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Extern block
+gen_res_t gen_extern(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen->extern_libs[gen->extern_libs_count++] =
+      (fzl_extern_lib_t){.name = (char *)node->ext.libname};
+
+  for (size_t i = 0; i < node->ext.typedefs_count; i++)
+    if (gen_common(gen, node->ext.typedefs[i]).error)
+      return gen_error;
+
+  for (size_t i = 0; i < node->ext.fns_count; i++)
+    if (gen_common(gen, node->ext.fns[i]).error)
+      return gen_error;
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_externfn.c

@@ -0,0 +1,135 @@
+#include <common/fzl_extern.h>
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/fzl_parser.h>
+#include <compiler/internals/gen.h>
+#include <compiler/utils/fzl_symtable.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char ex_argcn[256];
+char ex_retcn[256];
+
+// External function definition
+gen_res_t gen_externfn(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_gen_ctx_t *ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_FUNCTION, node);
+  if (!ctx)
+    return gen_error;
+
+  size_t args_remainder  = 2;
+  size_t args_count      = 0;
+  fzl_extern_arg_t *args = malloc(args_remainder * sizeof(fzl_extern_arg_t));
+  if (!args)
+    return gen_error;
+
+  for (size_t i = 0; i < node->ext_fn.args_count; i++)
+  {
+    fzl_node_t *argnode = node->ext_fn.args[i];
+    if (args_count >= args_remainder)
+    {
+      args_remainder *= 2;
+      fzl_extern_arg_t *newargs =
+          realloc(args, args_remainder * sizeof(fzl_extern_arg_t));
+      if (!newargs)
+      {
+        free(args);
+        return gen_error;
+      }
+
+      args = newargs;
+    }
+
+    if (argnode->type != FZL_NODETYPE_DECLARATION)
+    {
+      free(args);
+      return gen_error;
+    }
+
+    fzl_extern_arg_t *arg = &args[args_count++];
+
+    fzl_type_t argtype;
+    memset(ex_argcn, 0, sizeof(ex_argcn));
+
+    bool resolved =
+        gen_resolve_type(gen, argnode->var.type, &argtype, ex_argcn);
+    if (!resolved)
+    {
+      free(args);
+      return gen_error;
+    }
+
+    ssize_t slot = gen_resolve_extern_type(gen, ex_argcn);
+    if (slot == -1)
+      arg->type =
+          (fzl_extern_type_ref_t){.is_primitive = true, .primitive = argtype};
+    else
+      arg->type =
+          (fzl_extern_type_ref_t){.is_primitive = false, .type_slot = slot};
+
+    arg->name   = (char *)argnode->var.identifier->token->value;
+    arg->is_out = argnode->var.is_out;
+  }
+
+  ctx = gen_fin_ctx(gen);
+  if (!ctx)
+  {
+    free(args);
+    return gen_error;
+  }
+
+  fzl_type_t ret;
+  memset(ex_retcn, 0, sizeof(ex_retcn));
+
+  bool resolved = gen_resolve_type(gen, node->ext_fn.type, &ret, ex_retcn);
+  if (!resolved)
+  {
+    free(args);
+    return gen_error;
+  }
+
+  fzl_symtable_res_t res =
+      fzl_symt_put(gen->syms[0], node, node->ext_fn.name, ret, 0);
+  if (res != FZL_SYMTABLE_RESULT_OK)
+  {
+    free(args);
+    return gen_error;
+  }
+
+  if (ret == FZL_TYPE_OBJECT || ret == FZL_TYPE_STRUCT ||
+      ret == FZL_TYPE_HANDLE)
+  {
+    res = fzl_symt_setobjclass(gen->syms[0], node->ext_fn.name, ex_retcn);
+    if (res != FZL_SYMTABLE_RESULT_OK)
+    {
+      free(args);
+      return gen_error;
+    }
+  }
+
+  fzl_extern_fn_t *result = &gen->extern_fns[gen->extern_fns_count++];
+
+  ssize_t slot = gen_resolve_extern_type(gen, ex_retcn);
+  if (slot == -1)
+    result->ret_type =
+        (fzl_extern_type_ref_t){.is_primitive = true, .primitive = ret};
+  else
+    result->ret_type =
+        (fzl_extern_type_ref_t){.is_primitive = false, .type_slot = slot};
+
+  result->lib_slot    = gen->extern_libs_count - 1;
+  result->args        = args;
+  result->args_count  = args_count;
+  result->has_return  = ret != FZL_TYPE_NULL;
+  result->used_name   = node->ext_fn.name;
+  result->symbol_name = node->ext_fn.original_name ? node->ext_fn.original_name
+                                                  : node->ext_fn.name;
+
+  return gen_ok_null;
+}

src/compiler/generator/gen_field.c

@@ -0,0 +1,49 @@
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <string.h>
+
+// Field access
+gen_res_t gen_field(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_res_t parent_res = gen_common(gen, node->memb.parent);
+  if (parent_res.error)
+    return gen_error;
+
+  fzl_ctable_t *ct = NULL;
+  for (size_t i = 0; i < gen->classes_count; i++)
+  {
+    if (strcmp(parent_res.classname, gen->classes[i]->name) == 0)
+    {
+      ct = gen->classes[i];
+      break;
+    }
+  }
+
+  if (!ct)
+    return gen_error;
+
+  fzl_token_t *ftok = node->memb.field->token;
+  fzl_ctable_field_t ctf;
+  bool field_exists = false;
+  for (size_t i = 0; i < ct->fields_count; i++)
+  {
+    if (strcmp(ftok->value, ct->fields[i].name) == 0)
+    {
+      field_exists = true;
+      ctf          = ct->fields[i];
+      break;
+    }
+  }
+
+  if (!field_exists)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_GET_FIELD);
+  gen_word(gen, ctf.slot_index);
+
+  return (gen_res_t){
+      .error = false, .type = ctf.type, .classname = parent_res.classname};
+}

src/compiler/generator/gen_fmtstr.c

@@ -0,0 +1,21 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// Format string
+gen_res_t gen_fmtstr(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  for (size_t i = 0; i < node->list.entry_count; i++)
+    if (gen_common(gen, node->list.entries[i]).error)
+      return gen_error;
+
+  gen_op(gen, FZL_OPCODE_BUILD_STR);
+  gen_word(gen, node->list.entry_count);
+
+  return (gen_res_t){
+      .error = false, .type = FZL_TYPE_STRING, .classname = NULL};
+}

src/compiler/generator/gen_fn.c

@@ -0,0 +1,67 @@
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+char fn_typecn[256];
+
+// Function definition
+gen_res_t gen_fn(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_JMP);
+  size_t skip_ip = gen->ops_count;
+  gen_word(gen, (uint64_t)0);
+
+  fzl_type_t fntype;
+  memset(fn_typecn, 0, sizeof(fn_typecn));
+
+  bool resolved = gen_resolve_type(gen, node->fn.type, &fntype, fn_typecn);
+  if (!resolved)
+    return gen_error;
+
+  fzl_symtable_res_t putres =
+      fzl_symt_put(gen->syms[gen->syms_top - 1], node, node->fn.name->value,
+                   fntype, gen->ops_count);
+
+  if (putres != FZL_SYMTABLE_RESULT_OK)
+    return gen_error;
+
+  if (fntype == FZL_TYPE_OBJECT)
+  {
+    fzl_symtable_res_t updres = fzl_symt_setobjclass(
+        gen->syms[gen->syms_top - 1], node->fn.name->value, fn_typecn);
+    if (updres != FZL_SYMTABLE_RESULT_OK)
+      return gen_error;
+  }
+
+  fzl_gen_ctx_t *ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_FUNCTION, node);
+  if (!ctx)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_MK_ENVTABLE);
+
+  for (ssize_t i = node->fn.args_count - 1; i >= 0; i--)
+  {
+    if (gen_common(gen, node->fn.args[i]).error)
+      return gen_error;
+
+    gen_op(gen, FZL_OPCODE_WRITE);
+  }
+
+  if (gen_common(gen, node->fn.body).error)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_RM_ENVTABLE);
+  gen_op(gen, FZL_OPCODE_RET);
+  gen->ops[skip_ip] = gen->ops_count;
+
+  ctx = gen_fin_ctx(gen);
+  if (!ctx)
+    return gen_error;
+
+  return (gen_res_t){.error = false, .type = fntype, .classname = fn_typecn};
+}

src/compiler/generator/gen_handle.c

@@ -0,0 +1,13 @@
+#include <common/fzl_extern.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+
+// Opaque pointer
+gen_res_t gen_handle(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  type_buf.kind = FZL_EXTERN_KIND_HANDLE;
+  return gen_ok_null;
+}

src/compiler/generator/gen_identifier.c

@@ -0,0 +1,29 @@
+#include <compiler/internals/gen.h>
+
+// Identifier lookup
+gen_res_t gen_identifier(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_sym_t sym;
+  bool exists = false;
+  ssize_t i   = gen->syms_top - 1;
+  for (; i >= 0; i--)
+    if ((exists = fzl_symt_get(gen->syms[i], node->token->value, &sym)))
+      break;
+
+  if (!exists)
+    return gen_error;
+
+  if (!sym.slot_set)
+    return gen_error;
+
+  size_t depth = gen->syms_top - 1 - i;
+  gen_op(gen, FZL_OPCODE_LOAD_LOCAL);
+  gen_word(gen, depth);
+  gen_word(gen, sym.slot);
+
+  return (gen_res_t){
+      .error = false, .type = sym.type, .classname = sym.classname};
+}

src/compiler/generator/gen_literal.c

@@ -0,0 +1,59 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+gen_res_t gen_literal(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  if (node->token->type == FZL_TOKTYPE_STR_LITERAL)
+  {
+    size_t n = gen_add_const(
+        gen, (fzl_const_t){.type             = FZL_CONSTTYPE_STRING,
+                           .as.string.chars  = node->token->value,
+                           .as.string.length = node->token->value_sz});
+
+    gen_op(gen, FZL_OPCODE_LOADCONST);
+    gen_word(gen, n);
+
+    return (gen_res_t){
+        .error = false, .type = FZL_TYPE_STRING, .classname = NULL};
+  }
+
+  if (node->token->type == FZL_TOKTYPE_NUM_LITERAL)
+  {
+    gen_op(gen, FZL_OPCODE_PUSHNUM);
+
+    uint64_t num = strtol(node->token->value, NULL, 10);
+    gen_word(gen, num);
+
+    return (gen_res_t){.error = false, .type = FZL_TYPE_INT, .classname = NULL};
+  }
+
+  if (node->token->type == FZL_TOKTYPE_BOOL_LITERAL)
+  {
+    fzl_token_t *tok = node->token;
+    uint64_t val     = strcmp(tok->value, "true") == 0 ? 1 : 0;
+
+    gen_op(gen, FZL_OPCODE_PUSHBOOL);
+    gen_word(gen, val);
+
+    return (gen_res_t){
+        .error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+  }
+
+  if (node->token->type == FZL_TOKTYPE_NULL_LITERAL)
+  {
+    gen_op(gen, FZL_OPCODE_PUSHNUM);
+    gen_word(gen, 0);
+    gen_op(gen, FZL_OPCODE_DEREFERENCE);
+
+    return (gen_res_t){
+        .error = false, .type = FZL_TYPE_OBJECT, .classname = null_name};
+  }
+
+  return gen_error;
+}

src/compiler/generator/gen_logical.c

@@ -0,0 +1,29 @@
+#include <common/fzl_types.h>
+#include <compiler/internals/gen.h>
+#include <stdio.h>
+
+// Binary logical operations (and / or)
+gen_res_t gen_logical(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  gen_res_t left = gen_common(gen, node->binary_op.left);
+  if (left.error)
+    return left;
+
+  gen_res_t right = gen_common(gen, node->binary_op.right);
+  if (right.error)
+    return right;
+
+  if (!gen_is_types_compatible(left.type, right.type, left.classname,
+                               right.classname))
+    return gen_error;
+
+  if (node->type == FZL_NODETYPE_AND)
+    gen_op(gen, FZL_OPCODE_AND);
+  else
+    gen_op(gen, FZL_OPCODE_OR);
+
+  return (gen_res_t){.error = false, .type = FZL_TYPE_BOOL, .classname = NULL};
+}

src/compiler/generator/gen_loop.c

@@ -0,0 +1,63 @@
+#include <common/fzl_types.h>
+#include <compiler/fzl_gen.h>
+#include <compiler/internals/gen.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+// While or for loops
+gen_res_t gen_loop(fzl_gen_t *gen, fzl_node_t *node)
+{
+  if (!gen || !node)
+    return gen_error;
+
+  fzl_gen_ctx_t *ctx = gen_ctx(gen, FZL_GEN_CTX_TYPE_LOOP, node);
+  if (!ctx)
+    return gen_error;
+
+  gen_op(gen, FZL_OPCODE_MK_ENVTABLE);
+
+  if (node->loop.init)
+    if (gen_common(gen, node->loop.init).error)
+      return gen_error;
+
+  size_t start_ip = gen->ops_count;
+  if (node->loop.cond)
+  {
+    if (gen_common(gen, node->loop.cond).error)
+      return gen_error;
+  }
+  else
+  {
+    gen_op(gen, FZL_OPCODE_PUSHNUM);
+    gen_word(gen, 1);
+  }
+
+  gen_op(gen, FZL_OPCODE_JZ);
+  ctx->loop.breaks[ctx->loop.breaks_count++] = gen->ops_count;
+  gen_word(gen, 0);
+
+  if (gen_common(gen, node->loop.body).error)
+    return gen_error;
+
+  if (node->loop.step)
+    if (gen_common(gen, node->loop.step).error)
+      return gen_error;
+
+  gen_op(gen, FZL_OPCODE_JMP);
+  gen_word(gen, start_ip);
+
+  // backpatch `break`s
+  for (size_t i = 0; i < ctx->loop.breaks_count; i++)
+    gen->ops[ctx->loop.breaks[i]] = gen->ops_count;
+
+  gen_op(gen, FZL_OPCODE_RM_ENVTABLE);
+
+  for (size_t i = gen->syms_top - 1; i > ctx->level + 1; i--)
+    fzl_freesymt(gen->syms[--gen->syms_top]);
+
+  ctx = gen_fin_ctx(gen);
+  if (!ctx)
+    return gen_error;
+
+  return gen_ok_null;
+}