How is it needed for Map/Set? Those use SameValueZero, and don't have a sorting method.
On Sun, Sep 18, 2016 at 10:32 PM, Park Hyeonu <[email protected]> wrote: > Well, this proposal is not for check equality. Its purpose is to compare > two object that which object is `greater`. > > I'm sure this feature is already implemented for every modern js engines, > as it's needed to implement Map/Set. But we don't have js interface for it > yet. Thus proposal is to expose this functionality to userland application. > > 2016. 9. 19. 오후 2:26에 "Jordan Harband" <[email protected]>님이 작성: > > This may have already been proposed as https://github.com/sebmarkb >> age/ecmascript-shallow-equal - if so, you'll want to post your comments >> there. >> >> On Sun, Sep 18, 2016 at 10:10 PM, Park Hyeonu <[email protected]> wrote: >> >>> tl;dr - deterministic function that compares arbitrary objects >>> >>> I know now we have `Map` and `Set`, but sometimes we need more low level >>> ones. Especially for library developers. >>> >>> For the case, say, I want to implement a map whose key can be a >>> arbitrary number of objects. Currently this can only implemented as nested >>> map whose structure is `keylen -> key1 -> key2 -> ... -> value`. Not really >>> elegant. But if we have `Object.compare()`, `(key1, key2, ...) -> value` is >>> possible. >>> >>> As its intended purpose is to be used with custom map/set, I don't think >>> we should define how this function works in spec. Just guaranteed to be >>> deterministic in each runtime is enough. >>> >>> For detail, this function follows `(left: any, right: any) => number` >>> form. When `Object.is(left, right)` is true, `Object.compare(left, right)` >>> must return `0`. Otherwise, the result must be deterministic, means >>> whenever(in same runtime) we call this function with same arguments it >>> should return same value(or at least, always greater than/lesser 0). >>> >>> Seems good? >>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >>
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