add declaration with function support

src/parser/declaration/declaration.c

@@ -2,11 +2,12 @@
 #include "../../lexer/token.h"
 #include "../../memory.h"
 #include "../parser.h"
+#include "../literals/literals.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-ParsedValue *parse_declaration(char *file, DArray *parsed, DArray *tokens,
+ParsedValue *parse_declaration(char *file, DArray *tokens,
                               size_t *index) {
   (*index)++;
   error_if_finished(file, tokens, index);
@@ -14,6 +15,8 @@ ParsedValue *parse_declaration(char *file, DArray *parsed, DArray *tokens,
 
   ParsedValue * parsedValue = malloc(sizeof(ParsedValue));
   ParsedDeclaration * declaration = malloc(sizeof(ParsedDeclaration));
+  declaration->is_function = false;
+  declaration->from = parse_null();
   parsedValue->data = declaration;
   parsedValue->type = AST_DECLARATION;
 
@@ -23,8 +26,51 @@ ParsedValue *parse_declaration(char *file, DArray *parsed, DArray *tokens,
     exit(EXIT_FAILURE);
   }
   declaration->name = strcpy(checked_malloc(sizeof(token->value)), token->value);
+
   (*index)++;
-  if ((*index) >= tokens->size) return parsedValue;
+  if ((*index) >= tokens->size) {
+    return parsedValue;
+  }
   token = darray_get(tokens, *index);
+  if (token->type == TOKEN_LPAREN) {
+    declaration->is_function = true;
+    declaration->parameters = checked_malloc(sizeof(DArray));
+    darray_init(declaration->parameters, sizeof(char*));
+    (*index)++;
+    error_if_finished(file, tokens, index);
+    while(true) {
+      token = darray_get(tokens, *index);
+      if (token->type != TOKEN_IDENTIFIER) {
+        fprintf(stderr, "%s:%u:%u error: parameter names need to start with a letter or _, only use letters, digits, or _, and can't be keywords.\n",
+            file, token->line, token->column);
+        exit(EXIT_FAILURE);
+      }
+      darray_push(declaration->parameters, strcpy(checked_malloc(sizeof(token->value)), token->value));
+      (*index)++;
+      error_if_finished(file, tokens, index);
+      token = darray_get(tokens, *index);
+      if (token->type == TOKEN_RPAREN) {
+        (*index)++;
+        error_if_finished(file, tokens, index);
+        token = darray_get(tokens, *index);
+        break;
+      } else if (token->type != TOKEN_COMMA) {
+        fprintf(stderr, "%s:%u:%u error: expected comma\n",
+            file, token->line, token->column);
+        exit(EXIT_FAILURE);
+      }
+      (*index)++;
+      error_if_finished(file, tokens, index);
+    }
+  }
+  if (token->type != TOKEN_ASSIGN) return parsedValue;
+
+  (*index)++;
+  error_if_finished(file, tokens, index);
+  
+  free(declaration->from);
+
+  declaration->from = parse_token(file, tokens, index, true);
+
   return parsedValue;
 }