Zoltan Herczeg 3d797b8836 Implement the core of let/const statement. (#3239)
This patch implements the core part of let/const statements. Redeclarations are correctly
detected and separate contexts are correctly created for these statements. Register
optimizations are also emplyed whenever possible.

Lots of features are still missing:
 - checking the var statements in eval
 - const are treated as lets
 - single statement checks are missing
 - export declarations are exported as vars, let/const export is not supported

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com
2019-10-25 18:08:10 +02:00

43 lines
949 B
JavaScript

/* Copyright JS Foundation and other contributors, http://js.foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var a = 5;
var a = 6;
let b = 7;
assert (a === 6);
assert (this.a === 6);
assert (b === 7);
assert (this.b === undefined);
{
let c;
c = 8;
{
let c = 9;
assert (c === 9);
}
{
function c() { return 10 }
assert (c() === 10);
}
assert (c === 8);
}
assert (typeof c === "undefined");