Add switch case statement

parsing.cpp

@@ -234,6 +234,37 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0){
         scope->stmts.add(ast_pass(token));
       }
 
+      else if(token_match_keyword(keyword_switch)){
+        Ast_Switch *result = MAKE_AST(Ast_Switch, AST_SWITCH, token, AST_STMT);
+        result->value = parse_expr();
+        result->cases = {scratch};
+
+        token_expect(OPEN_SCOPE);
+        do{
+          if(token_match_keyword(keyword_default)){
+            result->default_scope = parse_stmt_scope();
+            continue;
+          }
+
+          Ast_Switch_Case *switch_case = MAKE_AST(Ast_Switch_Case, AST_SWITCH_CASE, token_get(), AST_STMT);
+          if(token_match_pound(pctx->intern("fallthrough"_s)))
+            switch_case->fallthrough = true;
+
+          switch_case->labels = {scratch};
+          do{
+            switch_case->labels.add(parse_expr());
+          }while(token_match(TK_Comma));
+          switch_case->labels = switch_case->labels.tight_copy(pctx->perm);
+
+          switch_case->scope = parse_stmt_scope();
+          result->cases.add(switch_case);
+        }while(token_match(SAME_SCOPE));
+        token_expect(CLOSE_SCOPE);
+        result->cases = result->cases.tight_copy(pctx->perm);
+
+        scope->stmts.add(result);
+      }
+
       else if(token_match_keyword(keyword_assert)){
         token_expect(TK_OpenParen);
         Ast_Expr *expr = parse_expr();