feat+fix: make compiler STRONGAAA

- FEAT: add source code length field in `fzl_reader_t` struct
- FIX: check name, lpair (lparen) and rpair (rparen) when lexing call
- FIX: check string literal termination
- FIX: increment position even on empty string to prevent infinite
lexing loop
- FIX: add string terminator in `fzl_mktoken` when allocating space for
string value
- FIX: add check for errors in recursevly called `walk`
- FIX: change source code holder from stack-stored `char[8192]` to
dynamically allocated with actual file size holder
- FIX: correct constant hasing util to hash actual string value instead
of link

src/compiler/fzl_parser.c

@@ -1,3 +1,4 @@
+#include "compiler/fzl_token.h"
 #include <compiler/fzl_parser.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -92,7 +93,12 @@ fzl_node_t *parse_expression(fzl_parser_t *parser, int precedence);
 fzl_node_t *parse_call(fzl_parser_t *parser)
 {
   fzl_token_t *tok = consume(parser); // <NAME>
-  consume(parser);                    // (
+  if (tok->type != FZL_TOKTYPE_NAME)
+    return NULL;
+
+  fzl_token_t *lpair = consume(parser); // (
+  if (lpair->type != FZL_TOKTYPE_LPAIR)
+    return NULL;
 
   fzl_node_t *node = fzl_mknode(FZL_NODETYPE_CALL, tok);
   node->list.entry_count = 0;
@@ -132,7 +138,10 @@ fzl_node_t *parse_call(fzl_parser_t *parser)
     }
   }
 
-  consume(parser);
+  fzl_token_t *rpair = consume(parser);
+  if (rpair->type != FZL_TOKTYPE_RPAIR)
+    return NULL;
+
   return node;
 }