Change Details

Steps to Reproduce: At https://th.wikipedia.org/wiki/Special:Abusefilter/test, paste the following code: ``` a := []; a[] := 0 ``` and then click the "Test" button Actual Results: An internal error occurs: ``` [XbkMfApAICoAAHOmRuQAAAAL] 2019-10-30 04:07:24: การยกเว้นข้อผิดพลาดร้ายแรงของประเภท "TypeError" ``` Expected Results: I think the semantics of `<e1>[] := <e2>` should be, mutating `<e1>`

Steps to Reproduce: At https://th.wikipedia.org/wiki/Special:Abusefilter/test, paste the following code: ``` a := []; a[] := 0 ``` and then click the "Test" button Actual Results: An internal error occurs: ``` [XbkMfApAICoAAHOmRuQAAAAL] 2019-10-30 04:07:24: การยกเว้นข้อผิดพลาดร้ายแรงของประเภท "TypeError" ``` Expected Results: I think the semantics of `<e1>[] := <e2>` should be, mutating `<e1>` to append `<e2>`, and the whole expression evaluates to `<e2>`.

Steps to Reproduce: At https://th.wikipedia.org/wiki/Special:Abusefilter/test, paste the following code: ``` a := []; a[] := 0 ``` and then click the "Test" button Actual Results: An internal error occurs: ``` [XbkMfApAICoAAHOmRuQAAAAL] 2019-10-30 04:07:24: การยกเว้นข้อผิดพลาดร้ายแรงของประเภท "TypeError" ``` Expected Results: I think the semantics of `<e1>[] := <e2>` should be, mutating `<e1>` to append `<e2>`, and the whole expression evaluates to `<e2>`.