implemented labels and goto parsing

examples/for.l

@@ -0,0 +1,21 @@
+import std::io;
+
+i32 main()
+{
+	[u32] list = [1, 2, 3, 4, 5];
+
+	// iterative loop
+	loop (0.., list) |i, v| {
+		printf("%d\n", i);
+	}
+
+	// conditional loop
+	loop a == 3 {
+
+	}
+
+	// infinite loop
+	loop {
+
+	}
+}

lc.c

@@ -76,6 +76,12 @@ void print_ast(ast_node *node, int depth) {
 			printf("Access: %.*s\n", (int)node->expr.access.member_len, node->expr.access.member);
 			print_ast(node->expr.access.expr, depth + 1);
 			break;
+		case NODE_LABEL:
+			printf("Label: %.*s\n", (int)node->expr.label.name_len, node->expr.label.name);
+			break;
+		case NODE_GOTO:
+			printf("Goto: %.*s\n", (int)node->expr.label.name_len, node->expr.label.name);
+			break;
 		case NODE_BINARY:
 			printf("BinaryOp (%s)\n", get_op_str(node->expr.binary.operator));
 			print_ast(node->expr.binary.left, depth + 1);
@@ -126,9 +132,6 @@ void print_ast(ast_node *node, int depth) {
 		case NODE_IF:
 			printf("IfStmt (Fields missing in struct)\n");
 			break;
-		case NODE_WHILE:
-			printf("WhileStmt (Fields missing in struct)\n");
-			break;
 		case NODE_VAR_DECL:
 			printf("VarDecl (Fields missing in struct)\n");
 			break;
@@ -136,7 +139,8 @@ void print_ast(ast_node *node, int depth) {
 			printf("FunctionDef (Fields missing in struct)\n");
 			break;
 		case NODE_RETURN:
-			printf("Return (Fields missing in struct)\n");
+			printf("Return:\n");
+			print_ast(node->expr.ret.value, depth + 1);
 			break;
 		default:
 			printf("Unknown Node Type: %d\n", node->type);

lexer.c

@@ -394,8 +394,7 @@ lexer *lexer_init(char *source, usize size, arena *arena)
 	trie_insert(keywords, lex->allocator, "struct", TOKEN_STRUCT);
 	trie_insert(keywords, lex->allocator, "enum", TOKEN_ENUM);
 	trie_insert(keywords, lex->allocator, "union", TOKEN_UNION);
-	trie_insert(keywords, lex->allocator, "while", TOKEN_WHILE);
+	trie_insert(keywords, lex->allocator, "loop", TOKEN_LOOP);
-	trie_insert(keywords, lex->allocator, "for", TOKEN_FOR);
 	trie_insert(keywords, lex->allocator, "goto", TOKEN_GOTO);
 	trie_insert(keywords, lex->allocator, "if", TOKEN_IF);
 	trie_insert(keywords, lex->allocator, "else", TOKEN_ELSE);

lexer.h

@@ -57,9 +57,8 @@ typedef enum {
 	TOKEN_STRING,
 	TOKEN_CHAR,
 
-	TOKEN_WHILE,
-	TOKEN_FOR,
 	TOKEN_GOTO,
+	TOKEN_LOOP,
 	TOKEN_IF,
 	TOKEN_ELSE,
 	TOKEN_SWITCH,

parser.c

@@ -66,8 +66,7 @@ static void parser_sync(parser *p)
 			case TOKEN_STRUCT:
 			case TOKEN_ENUM:
 			case TOKEN_IF:
-			case TOKEN_WHILE:
+			case TOKEN_LOOP:
-			case TOKEN_FOR:
 			case TOKEN_DO:
 			case TOKEN_RETURN:
 			case TOKEN_SWITCH:
@@ -380,7 +379,7 @@ static ast_node *parse_statement(parser *p)
 {
 	if (match(p, TOKEN_BREAK)) {
 		if (!match(p, TOKEN_SEMICOLON)) {
-			error(p, "expected `;`.");
+			error(p, "expected `;` after `break`.");
 			return NULL;
 		}
 		ast_node *node = arena_alloc(p->allocator, sizeof(ast_node));
@@ -390,7 +389,7 @@ static ast_node *parse_statement(parser *p)
 		ast_node *expr = parse_expression(p);
 
 		if (!expr) {
-			error(p, "expected expression.");
+			error(p, "expected expression after `return`.");
 			return NULL;
 		}
 		if (!match(p, TOKEN_SEMICOLON)) {
@@ -402,13 +401,38 @@ static ast_node *parse_statement(parser *p)
 		node->type = NODE_RETURN;
 		node->expr.ret.value = expr;
 		return node;
+	} else if (match_peek(p, TOKEN_IDENTIFIER) && p->tokens->next && p->tokens->next->type == TOKEN_COLON) {
+		/* In this case, this is a label. */
+		ast_node *node = arena_alloc(p->allocator, sizeof(ast_node));
+		node->type = NODE_LABEL;
+		node->expr.label.name = p->tokens->lexeme;
+		node->expr.label.name_len = p->tokens->lexeme_len;
+		advance(p);
+		/* Consume `:` */
+		advance(p);
+		return node;
+	} else if (match(p, TOKEN_GOTO)) {
+		if (!match_peek(p, TOKEN_IDENTIFIER)) {
+			error(p, "expected label identifier after `goto`.");
+			return NULL;
+		}
+		ast_node *node = arena_alloc(p->allocator, sizeof(ast_node));
+		node->type = NODE_GOTO;
+		node->expr.label.name = p->tokens->lexeme;
+		node->expr.label.name_len = p->tokens->lexeme_len;
+		advance(p);
+		if (!match(p, TOKEN_SEMICOLON)) {
+			error(p, "expected `;` after `goto`.");
+			return NULL;
+		}
+		return node;
 	} else  {
 		ast_node *expr = parse_expression(p);
 		if (!expr) {
 			return NULL;
 		}
 		if (!match(p, TOKEN_SEMICOLON)) {
-			error(p, "expected `;`.");
+			error(p, "expected `;` after expression.");
 			return NULL;
 		}
 		return expr;

parser.h

@@ -75,9 +75,10 @@ typedef enum {
 	NODE_POSTFIX,
 	NODE_BREAK,
 	NODE_RETURN,
-	NODE_SWITCH,
+	NODE_LABEL,
-	NODE_FOR,
+	NODE_GOTO,
 	NODE_DO,
+	NODE_FOR,
 	NODE_WHILE,
 	NODE_IF,
 	NODE_COMPOUND,
@@ -87,13 +88,17 @@ typedef enum {
 	NODE_VAR_DECL,
 	NODE_FUNCTION,
 	NODE_TERNARY,
-	NODE_GOTO,
+	NODE_SWITCH,
 	NODE_UNIT,
 } node_type;
 
 typedef struct _ast_node {
 	node_type type;
 	union {
+		struct {
+			char *name;
+			usize name_len;
+		} label; // both label and goto
 		struct {
 			struct _ast_node *left;
 			struct _ast_node *right;

test.c

@@ -1 +1,3 @@
-x[3];
+test:
+goto test;
+return 5;