From c40e5c2d0f7ee9e8ebaa76e504453b1d3b7ebba6 Mon Sep 17 00:00:00 2001
From: matteo <matteo.flebus@epita.fr>
Date: Wed, 28 Jan 2026 19:16:48 +0100
Subject: [PATCH] feat(parser): helper static function

---
 src/parser/grammar_basic.c | 42 +++++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/src/parser/grammar_basic.c b/src/parser/grammar_basic.c
index fb1b12d..17e006f 100644
--- a/src/parser/grammar_basic.c
+++ b/src/parser/grammar_basic.c
@@ -169,7 +169,7 @@ struct ast *parse_command(struct lexer_context *ctx)
     }
 }
 
-/* @brief: frees command_elements and redirections lists
+/* @brief: frees command_elements and redirections lists (helper func)
  * @return: NULL
  */
 static void *err_simple_command(struct list *command_elements,
@@ -293,6 +293,17 @@ struct ast *parse_shell_command(struct lexer_context *ctx)
     return parse_if_rule(ctx);
 }
 
+/* @brief: frees all the arguments. (helper func)
+ * @return: NULL.
+ */
+static void *err_if_rule(struct ast **cond, struct ast **then_clause, struct ast **else_clause)
+{
+    ast_free(cond);
+    ast_free(then_clause);
+    ast_free(else_clause);
+    return NULL;
+}
+
 struct ast *parse_if_rule(struct lexer_context *ctx)
 {
     // If keyword
@@ -311,38 +322,34 @@ struct ast *parse_if_rule(struct lexer_context *ctx)
     token = POP_TOKEN();
     if (token->type != TOKEN_THEN)
     {
-        ast_free(&condition_content);
         perror("Expected the 'then' keyword but token has different type");
-        return NULL;
+        return err_if_rule(&condition_content, NULL, NULL);
     }
 
     // Then content
     struct ast *then_content = parse_compound_list(ctx);
     if (then_content == NULL)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, NULL);
     }
 
+    struct ast *else_content = NULL;
     // Eventual else/elif clause(s)
-    struct ast *else_content = parse_else_clause(ctx);
-    if (else_content == NULL)
+    if (is_first(*token, RULE_ELSE_CLAUSE))
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        return NULL;
+        else_content = parse_else_clause(ctx);
+        if (else_content == NULL)
+        {
+            return err_if_rule(&condition_content, &then_content, NULL);
+        }
     }
 
     // Fi keyword
     token = POP_TOKEN();
     if (token->type != TOKEN_FI)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        ast_free(&else_content);
         perror("Expected the 'fi' keyword but token has different type");
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, &else_content);
     }
 
     // Result
@@ -350,11 +357,8 @@ struct ast *parse_if_rule(struct lexer_context *ctx)
         ast_create_if(condition_content, then_content, else_content);
     if (result == NULL)
     {
-        ast_free(&condition_content);
-        ast_free(&then_content);
-        ast_free(&else_content);
         perror("Internal error: could not create a new AST (AST_IF)");
-        return NULL;
+        return err_if_rule(&condition_content, &then_content, &else_content);
     }
 
     return result;