From 664affc6d36506cc1ad0d2af53f918e8a0d79525 Mon Sep 17 00:00:00 2001
From: Lorenzo Torres <lorenzo@sagittarius-a.org>
Date: Wed, 3 Dec 2025 09:59:09 +0100
Subject: [PATCH] implemented structure parsing

---
 lc.c     |  8 +++++
 parser.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 parser.h | 13 ++++++--
 test.c   |  5 ++-
 4 files changed, 119 insertions(+), 4 deletions(-)

diff --git a/lc.c b/lc.c
index 5557c7a..b643372 100644
--- a/lc.c
+++ b/lc.c
@@ -134,6 +134,14 @@ void print_ast(ast_node *node, int depth) {
 				current = current->expr.unit_node.next;
 			}
 			break;
+		case NODE_STRUCT:
+			printf("Struct: %.*s\n", (int)node->expr.structure.name_len, node->expr.structure.name);
+			member *m = node->expr.structure.members;
+			while (m) {
+				print_ast(m->type, depth + 1);
+				m = m->next;
+			}
+			break;
 		case NODE_IF:
 			printf("IfStmt (Fields missing in struct)\n");
 			break;
diff --git a/parser.c b/parser.c
index 3d4b247..660c86e 100644
--- a/parser.c
+++ b/parser.c
@@ -676,6 +676,99 @@ static ast_node *parse_while(parser *p)
 	return node;
 }
 
+static ast_node *parse_struct(parser *p);
+static member *parse_member(parser *p)
+{
+	ast_node *type = NULL;
+	
+	if (match(p, TOKEN_STRUCT)) {
+		type = parse_struct(p);
+	}
+	if (!type) {
+		type = parse_factor(p);
+		if (!type) {
+			error(p, "expected struct definition or identifier.");
+			return NULL;
+		}
+		if (type->type != NODE_IDENTIFIER) {
+			error(p, "expected struct definition or identifier.");
+			return NULL;
+		}
+	}
+
+
+	if (!match_peek(p, TOKEN_IDENTIFIER)) {
+		error(p, "expected identifier.");
+		return NULL;
+	}
+
+	member *m = arena_alloc(p->allocator, sizeof(member));
+	m->type = type;
+	m->name = peek(p)->lexeme;
+	m->name_len = peek(p)->lexeme_len;
+	advance(p);
+
+
+	return m;
+}
+
+static ast_node *parse_struct(parser *p)
+{
+	ast_node *structure = arena_alloc(p->allocator, sizeof(ast_node));
+	structure->type = NODE_STRUCT;
+	if (match_peek(p, TOKEN_IDENTIFIER)) {
+		/* Named structure */
+		structure->expr.structure.name = peek(p)->lexeme;
+		structure->expr.structure.name_len = peek(p)->lexeme_len;
+		advance(p);
+	} else if (!match_peek(p, TOKEN_LCURLY)) {
+		error(p, "expected identifier or `{`.");
+		return NULL;
+	} else {
+		structure->expr.structure.name = NULL;
+		structure->expr.structure.name_len = 0;
+	}
+
+	if (!match(p, TOKEN_LCURLY)) {
+		error(p, "expected `{`.");
+		return NULL;
+	}
+
+	member *prev = parse_member(p);
+	member *head = prev;
+	structure->expr.structure.members = head;
+	if (!prev) {
+		error(p, "invalid struct definition. Structs should contain at least 1 member.");
+		return NULL;
+	}
+	if (!match(p, TOKEN_COMMA)) {
+		if (!match(p, TOKEN_RCURLY)) {
+			error(p, "expected `,`.");
+			return NULL;
+		} else {
+			return structure;
+		}
+	}
+	while (!match(p, TOKEN_RCURLY)) {
+		member *current = parse_member(p);
+		if (!current) {
+			error(p, "expected member definition.");
+			return NULL;
+		}
+		prev->next = current;
+		if (!match(p, TOKEN_COMMA)) {
+			if (!match_peek(p, TOKEN_RCURLY)) {
+				error(p, "expected `,`.");
+				return NULL;
+			}
+		}
+
+		prev = current;
+	}
+
+	return structure;
+}
+
 static ast_node *parse_statement(parser *p)
 {
 	if (match(p, TOKEN_BREAK))
@@ -802,6 +895,10 @@ static ast_node *parse_statement(parser *p)
 
 		return node;
 	}
+	else if (match(p, TOKEN_STRUCT))
+	{
+		return parse_struct(p);
+	}
 	else
 	{
 		ast_node *expr = parse_expression(p);
diff --git a/parser.h b/parser.h
index 57068e7..2fa02b8 100644
--- a/parser.h
+++ b/parser.h
@@ -4,6 +4,8 @@
 #include "lexer.h"
 #include "utils.h"
 
+struct _ast_node;
+
 typedef enum {
 	OP_PLUS, // +
 	OP_MINUS, // -
@@ -49,11 +51,11 @@ typedef enum {
 	LAYOUT_EXTERN
 } struct_layout;
 
-typedef struct {
-	char *type_name;
-	usize type_len;
+typedef struct _member {
+	struct _ast_node *type;
 	char *name;
 	usize name_len;
+	struct _member *next;
 } member;
 
 typedef struct {
@@ -177,6 +179,11 @@ typedef struct _ast_node {
 			char *type;
 			usize type_len;
 		} var_decl;
+		struct {
+			member *members;
+			char *name;
+			usize name_len;
+		} structure;
 	} expr;
 } ast_node;
 
diff --git a/test.c b/test.c
index 0064f08..544384a 100644
--- a/test.c
+++ b/test.c
@@ -1 +1,4 @@
-u32 a = 3;
+struct {
+	struct { u32 x, u32 y } a,
+	u32 b,
+}