#1464 — 13.5 Class Definitions, Static Semantics: remove Identifier name restriction (eval, arguments)

bug_id: 1464
creation_ts: 2013-05-02 08:51:00 -0700
short_desc: 13.5 Class Definitions, Static Semantics: remove Identifier name restriction (eval, arguments)
delta_ts: 2013-08-23 08:22:33 -0700
product: Draft for 6th Edition
component: technical issue
version: Rev 14: March 8, 2013 Draft
rep_platform: All
op_sys: All
bug_status: RESOLVED
resolution: FIXED
priority: Normal
bug_severity: enhancement
everconfirmed: true
reporter: Rick Waldron
assigned_to: Allen Wirfs-Brock
cc: ["andrebargull", "waldron.rick"]

commentid: 3701
comment_count: 0
who: Rick Waldron
bug_when: 2013-05-02 08:51:29 -0700

Based on the discovery and discussion here: https://github.com/jshint/jshint/pull/1048/files#r4055231

Remove:

- It is a Syntax Error if BoundNames of BindingIdentifier contains either ″eval″ or ″arguments″

commentid: 3827
comment_count: 1
who: Allen Wirfs-Brock
bug_when: 2013-05-13 12:51:00 -0700

Do we really want to allow binding of "eval" and "arguments" using class, let, and const? We would totally outlaw all declarations of those names (like we do in strict mode) except that we have to allow them in non-strict var/function/catch for legacy compatibility. But here we are talking about new declaration forms so there is no legacy to be compatible with.

Is there an actual record of a discussion on this issue somewhere? I don't see it addressed in the jshint class issue.

commentid: 3828
comment_count: 2
who: Rick Waldron
bug_when: 2013-05-13 12:53:17 -0700

I dont know why github hides older discussion, but here's the direct link:

https://github.com/jshint/jshint/pull/1048#discussion_r4055231

commentid: 3832
comment_count: 3
who: Allen Wirfs-Brock
bug_when: 2013-05-13 13:50:30 -0700

Thanks, got it.

The explicit restriction for ClassDeclaration is already gone from the draft and the same restrictions apply there as to any other use of BindingIdentifier (which is illegal in strict code)

I still think there is an argument for never allowing the "eval" and "arguments" in new declaration form, even for non-strict code. Do you recall whether we have discussed this at TC39?

commentid: 3834
comment_count: 4
who: Rick Waldron
bug_when: 2013-05-13 14:14:36 -0700

We haven't, but I would be in favor of forbidding these identifiers by default.

I wont be in London, you may speak for me on this issue.

commentid: 4963
comment_count: 5
who: André Bargull
bug_when: 2013-08-17 04:30:39 -0700

Also see bug 1729

commentid: 4983
comment_count: 6
who: Allen Wirfs-Brock
bug_when: 2013-08-19 18:02:23 -0700

fixed in rev17 editor's draft.

A class definition is always strict code so it can't create bindings named 'eval' or 'arguments'

commentid: 5081
comment_count: 7
who: Allen Wirfs-Brock
bug_when: 2013-08-23 08:22:33 -0700

fixed in rev17, August 23, 2013 draft

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#1464 — 13.5 Class Definitions, Static Semantics: remove Identifier name restriction (eval, arguments)