From 4c5ffb35d50d514e3df4788e7cf38245c0127883 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Sat, 2 Mar 2019 23:01:51 +0100
Subject: Add variable declaration without assignment

---
 src/parser.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

(limited to 'src')

diff --git a/src/parser.c b/src/parser.c
index 7588bda..6ea8d1d 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -72,8 +72,9 @@ static CHECK_RESULT int parser_parse_body_loop(Parser *self, Buffer *body_list,
 /*
 LHS = 'const'|'var' IDENTIFIER
 */
-static CHECK_RESULT int parser_parse_lhs(Parser *self, LhsExpr **result) {
+static CHECK_RESULT int parser_parse_lhs(Parser *self, LhsExpr **result, bool *assignment) {
     bool isConst;
+    bool match;
     BufferView var_name;
     *result = NULL;
 
@@ -90,6 +91,23 @@ static CHECK_RESULT int parser_parse_lhs(Parser *self, LhsExpr **result) {
     amal_log_debug("var name: %.*s", (int)var_name.size, var_name.data);
     return_if_error(scoped_allocator_alloc(self->allocator, sizeof(LhsExpr), (void**)result));
     lhsexpr_init(*result, isConst, var_name);
+
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_EQUALS, &match));
+    if(match) {
+        *assignment = bool_true;
+        return PARSER_OK;
+    }
+    
+    *assignment = bool_false;
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_SEMICOLON, &match));
+    if(match && isConst) {
+        self->error = tokenizer_create_error(&self->tokenizer, "const variable declaration requires assignment (expected '=', got ';')");
+        return PARSER_UNEXPECTED_TOKEN;
+    }
+    if(!match) {
+        self->error = tokenizer_create_error(&self->tokenizer, "Expected '=' or ';'");
+        return PARSER_UNEXPECTED_TOKEN;
+    }
     return PARSER_OK;
 }
 
@@ -273,29 +291,18 @@ BODY =  LHS ';' |
 Note: Semicolon is not required for closures, structs and tables
 */
 int parser_parse_body(Parser *self, Ast *ast) {
-    bool match;
+    bool assignment;
     LhsExpr *lhs_expr;
     Ast rhs_expr;
     rhs_expr = ast_none();
 
-    return_if_error(parser_parse_lhs(self, &lhs_expr));
-    if(lhs_expr) {
-        return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_EQUALS, &match));
-        if(match)
-            goto rhs;
-        
-        return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_SEMICOLON, &match));
-        if(!match) {
-            self->error = tokenizer_create_error(&self->tokenizer, "Expected '=' or ';'");
-            return PARSER_UNEXPECTED_TOKEN;
-        }
-
+    return_if_error(parser_parse_lhs(self, &lhs_expr, &assignment));
+    if(!assignment) {
         ast->type = AST_LHS;
         ast->value.lhs_expr = lhs_expr;
         return PARSER_OK;
     }
     
-    rhs:
     return_if_error(parser_parse_rhs_start(self, &rhs_expr));
     if(lhs_expr) {
         lhs_expr->rhs_expr = rhs_expr;
-- 
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