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#4316 — 12.14.5 - Omitted Productions

• bug_id: 4316
• creation_ts: 2015-04-17 09:50:00 -0700
• short_desc: 12.14.5 - Omitted Productions
• delta_ts: 2015-04-17 22:15:34 -0700
• product: Draft for 7th Edition
• component: Deferred from 6th edition
• version: unspecified
• rep_platform: All
• op_sys: All
• bug_status: CONFIRMED
• priority: Normal
• bug_severity: enhancement
• everconfirmed: true
• reporter: mike
• assigned_to: Allen Wirfs-Brock
• cc: jmdyck

---

• commentid: 14284
• comment_count: 0
• who: mike
• bug_when: 2015-04-17 09:50:37 -0700

Section 12.14.5 Destructuring Assignment lists the valid productions for ArrayAssignmentPattern as:

> ArrayAssignmentPattern[Yield] :
> [ Elisionopt AssignmentRestElement[?Yield]opt ]
> [ AssignmentElementList[?Yield] ]
> [ AssignmentElementList[?Yield] , Elisionopt AssignmentRestElement[?Yield]opt ]

However, 12.14.5.2 (Runtime Semantics: DestructuringAssignmentEvaluation) lists semantics for two additional productions, namely:

> ArrayAssignmentPattern : [ ]

and

> ArrayAssignmentPattern : [ Elision ]

The grammar initially defined in 12.14.5 should be updated to include these productions.

---

• commentid: 14295
• comment_count: 1
• who: Michael Dyck
• bug_when: 2015-04-17 22:15:34 -0700

Those aren't "additional" productions, they're just two possible 'expansions' of the defining production you quoted. (Note that the first RHS has two optional symbols, and see section 5.1.5.)