tc39/ecma262

Removal of Object type-check from GetIterator() algorithm

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#746 创建于 2016年12月6日

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 (13 评论) (0 反应) (0 负责人)HTML (15,626 star) (1,409 fork)batch import
good first issueneeds consensusneeds specification text

描述

The If Type(iterator) is not Object, throw a TypeError exception. step is generally not implemented by engines, see https://jsfiddle.net/gj3uaw1t/ for an example. V8 does implement this step for yield*, but not other uses of GetIterator().

It would be cool if we could remove this from the spec and have common behaviour among implementations (it seems a recent version of SpiderMonkey has added the typecheck, breaking compatibility between FF and Chrome/Safari in this very unlikely situation).

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研究方向
The issue proposes removing the type check step in the GetIterator() algorithm from the ECMAScript specification. Look for the relevant section in the specification (likely in the 'ECMAScript Language: Iteration' part) and identify the exact line to delete. The comments indicate that most engines already omit this check, so the change aligns with common behavior. Ensure that the removal is consistent with the rest of the spec and update any related cross references if necessary.