feat: implement format strings

src/compiler/fzl_reader.c

@@ -251,11 +251,83 @@ void skip_comment(fzl_reader_t *reader)
   }
 }
 
+// Parse string format
+fzl_token_t *parse_fmtstring_part(fzl_reader_t *reader)
+{
+  size_t p  = reader->position;
+  char *src = reader->source;
+
+  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 (src[p] == '{')
+  {
+    move(reader, 1);
+    fzl_token_t *id = parse_name(reader);
+
+    if (id == NULL || src[reader->position] != '}')
+    {
+      snprintf(last_err, sizeof(last_err),
+               "'%s':%zu:%zu => failed to parse format string", l.filename,
+               l.line, l.col);
+      fzl_freetoken(id);
+      return NULL;
+    }
+
+    move(reader, 1);
+    return id;
+  }
+
+  if (src[p] == '"')
+  {
+    move(reader, 1);
+
+    return fzl_mktoken(FZL_TOKTYPE_STR_FORMAT_END, l.line, l.col, NULL, 0,
+                       l.filename);
+  }
+
+  size_t size = 0;
+  size_t lpos = p;
+
+  do
+  {
+    if (src[lpos + 1] == '"')
+      break;
+
+    size++;
+    lpos++;
+  } while (lpos < reader->size && reader->source[lpos] != '{' &&
+           reader->source[lpos] != '"');
+
+  ok = fzl_linked_getpos(reader->linked, reader->position, &l);
+  if (!ok)
+  {
+    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
+    return NULL;
+  }
+
+  char *value = malloc(size);
+  memcpy(value, reader->source + reader->position, size);
+  fzl_token_t *tok = fzl_mktoken(FZL_TOKTYPE_STR_LITERAL, l.line, l.col, value,
+                                 size, l.filename);
+  free(value);
+  move(reader, size);
+
+  return tok;
+}
+
 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;
@@ -268,7 +340,13 @@ int fzl_read(fzl_reader_t *reader)
       continue;
     }
 
-    if (curr == '\'' || curr == '"')
+    if (is_format_str)
+    {
+      token = parse_fmtstring_part(reader);
+      if (token && token->type == FZL_TOKTYPE_STR_FORMAT_END)
+        is_format_str = false;
+    }
+    else if (curr == '\'' || curr == '"')
       token = parse_string_literal(reader);
     else if (curr == '/' && reader->source[p + 1] == '/')
     {
@@ -321,6 +399,12 @@ int fzl_read(fzl_reader_t *reader)
       token = add_single(reader, FZL_TOKTYPE_PERCENT);
     else if (curr == '=')
       token = add_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);