Add if statements

new_parse.cpp

@@ -59,6 +59,17 @@ token_is(Token_Kind kind, S64 lookahead = 0){
   return 0;
 }
 
+function Token *
+token_is_keyword(Intern_String keyword, S64 lookahead = 0){
+  Token *token = token_get(lookahead);
+  if(token->kind == TK_Keyword){
+    if(keyword.str == token->intern_val.str){
+      return token;
+    }
+  }
+  return 0;
+}
+
 function Token *
 token_match(Token_Kind kind){
   Token *token = token_get();
@@ -182,10 +193,37 @@ parse_block(){
         if(!token_is_scope()) result->expr = parse_expr();
         stmts.add(result);
       }
+      else if(token_match_keyword(keyword_if)){
+        Array<Ast_If_Node *> if_nodes = {scratch};
+        Ast_Expr *expr = parse_expr();
+        Ast_Block *block = parse_block();
+        Ast_If_Node *if_node = ast_if_node(token, expr, block);
+        if_nodes.add(if_node);
+
+        while(token_is(SAME_SCOPE) && token_is_keyword(keyword_else, 1)){
+          token_next();
+          token = token_next();
+          if(token_match_keyword(keyword_if)){
+            Ast_Expr *expr = parse_expr();
+            Ast_Block *block = parse_block();
+            Ast_If_Node *if_node = ast_if_node(token, expr, block);
+            if_nodes.add(if_node);
+          }
+          else{
+            Ast_Block *block = parse_block();
+            Ast_If_Node *if_node = ast_if_node(token, 0, block);
+            if_nodes.add(if_node);
+            break;
+          }
+        }
+        Ast_If *result_if = ast_if(token, if_nodes);
+        stmts.add(result_if);
+
+      }
       else{
         Ast_Decl *result = parse_decl(false);
         if(result) stmts.add(result);
-        else parsing_error(token, "Unexpected token while parsing statement");
+        else parsing_error(token, "Unexpected token [%s] while parsing statement", token_kind_string(token->kind).str);
       }
     } while(token_match(SAME_SCOPE));
     token_expect(CLOSE_SCOPE);