From 132f4f3a539c012f4345d8c5a97947c524be3ba0 Mon Sep 17 00:00:00 2001
From: matteo <matteo.flebus@epita.fr>
Date: Sat, 31 Jan 2026 13:24:44 +0100
Subject: [PATCH] feat(parser + ast): function parsing support

---
 src/parser/grammar_advanced.c | 51 ++++++++++++++++++++++++++++++++---
 src/parser/grammar_advanced.h |  2 +-
 src/parser/grammar_basic.c    |  1 -
 src/utils/ast/ast_function.c  |  2 +-
 src/utils/ast/ast_function.h  |  9 ++++---
 5 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/src/parser/grammar_advanced.c b/src/parser/grammar_advanced.c
index 22e3b9b..9968ba6 100644
--- a/src/parser/grammar_advanced.c
+++ b/src/parser/grammar_advanced.c
@@ -149,12 +149,55 @@ struct ast *parse_prefix(struct lexer_context *ctx)
     }
 }
 
-// TODO NOT IMPLEMENTED
 struct ast *parse_funcdec(struct lexer_context *ctx)
 {
-    (void)ctx;
-    perror("Error: usage of a not implemented function (parse_funcdec)");
-    return NULL;
+    struct token *token = PEEK_TOKEN();
+    struct ast *value = NULL;
+    char *func_name = NULL;
+
+    if (token->type != TOKEN_WORD)
+    {
+        return NULL;
+    }
+
+    // word -> func name
+    POP_TOKEN();
+    func_name = strdup(token->data);
+
+    // (
+    token = PEEK_TOKEN();
+    if (token->type != TOKEN_LEFT_PAREN)
+    {
+        free(func_name);
+        return NULL;
+    }
+    POP_TOKEN();
+
+    // )
+    token = PEEK_TOKEN();
+    if (token->type != TOKEN_RIGHT_PAREN)
+    {
+        free(func_name);
+        return NULL;
+    }
+    POP_TOKEN();
+    token = PEEK_TOKEN();
+
+    // { \n }
+    while (token->type == TOKEN_NEWLINE)
+    {
+        POP_TOKEN();
+        token = PEEK_TOKEN();
+    }
+
+    // shell_command -> value
+    value = parse_shell_command(ctx);
+    if (value == NULL)
+    {
+        free(name);
+        return NULL;
+    }
+    return ast_create_function(name, value);
 }
 
 struct ast *parse_for(struct lexer_context *ctx)
diff --git a/src/parser/grammar_advanced.h b/src/parser/grammar_advanced.h
index 2b9cc63..1b074ad 100644
--- a/src/parser/grammar_advanced.h
+++ b/src/parser/grammar_advanced.h
@@ -26,7 +26,7 @@ struct ast *parse_prefix(struct lexer_context *ctx);
 
 /*
  * @brief parses a funcdec rule
- * @warning NOT IMPLEMENTED
+ * @warning Work in progress
  *
  * @code funcdec = WORD '(' ')' {'\n'} shell_command ;
  *
diff --git a/src/parser/grammar_basic.c b/src/parser/grammar_basic.c
index df103fc..d86abb6 100644
--- a/src/parser/grammar_basic.c
+++ b/src/parser/grammar_basic.c
@@ -223,7 +223,6 @@ struct ast *parse_command(struct lexer_context *ctx)
     {
         result = parse_shell_command(ctx);
     }
-    // WARNING funcdec seems to require a LL(2) parser
     else if (is_first(*token, RULE_FUNCDEC))
     {
         result = parse_funcdec(ctx);
diff --git a/src/utils/ast/ast_function.c b/src/utils/ast/ast_function.c
index edd53e0..b0356c1 100644
--- a/src/utils/ast/ast_function.c
+++ b/src/utils/ast/ast_function.c
@@ -23,7 +23,7 @@ struct ast *ast_create_function(char *name, struct ast *value)
     if (!function_data)
         return NULL;
 
-    function_data->name = strdup(name);
+    function_data->name = name;
     function_data->value = value;
 
     return ast_create(AST_FUNCTION, function_data);
diff --git a/src/utils/ast/ast_function.h b/src/utils/ast/ast_function.h
index 9294295..f6171dc 100644
--- a/src/utils/ast/ast_function.h
+++ b/src/utils/ast/ast_function.h
@@ -9,18 +9,19 @@ struct ast_function
 
 
 /**
- * Checks if the given AST node is an ast_function
+ * @brief: Checks if the given AST node is an ast_function
  */
 bool ast_is_function(struct ast *node);
 
 /**
- * Retrieves the function data from the given AST node.
- * Assumes that the node is of type AST_function.
+ * @brief: Retrieves the function data from the given AST node.
+ *         Assumes that the node is of type AST_function.
  */
 struct ast_function *ast_get_function(struct ast *node);
 
 /**
- * Creates a new AST node representing an AST_function
+ * @brief: Creates a new AST node representing an AST_function
+ * @warning: name must be already allocated.
  */
 struct ast *ast_create_function(char *name, struct ast *value);
 /*