parser: Create parser for function with return statements

This is a very limited parser implementation which parses a single
function with return type i32 and body containing a return number statement.

The parser doesn't show the 'filepath:row:col' when it fails, a future
improvement would be display it to easy find where the compilation
problem is located.

The ast_nodes are taking the token.value ownership (which is a really
bad design since not all token.value ownership has been taken causing
memory leaking) but we never free them.  For a future fix we could use a
string_view instead since we never change the original source code. The
string_view will also improve the performance a lot avoiding unnecessary
heap memory allocation.

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/pipac.c b/src/pipac.c
index f1e5865..0df4a08 100644
--- a/src/pipac.c
+++ b/src/pipac.c
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "lexer.h"
+#include "parser.h"
 
 void
 print_usage()
@@ -46,8 +47,12 @@ main(int argc, char **argv)
   lexer_init(&lexer, filepath);
 
   printf("[INFO]: %ld bytes loaded [filename='%s']\n", lexer.srclen, lexer.filepath);
+  
+  parser_t parser;
+  parser_init(&parser, &lexer);
+  ast_function_t func = parser_parse_function(&parser);
 
-  print_tokens(&lexer);
+  printf("function name='%s' and return type '%d' with value %d\n", func.name, func.return_type, func.body.number);
 
   return EXIT_SUCCESS;
 }