Is object identity the inverse of hash? So myObj == identity(hash(myObj))? Then weakly keyed or mapped tables are obviously possible, even though they'll have to be manually cleared of expired values.
Unfortunately, while this may support encoding weak mappings, I suspect a feature like that is used more often in frameworks than application code, so there might be a big penalty. ActionScript 3 introduced a Dictionary object that performs weak mappings -- perhaps that can be used to find a concrete comparison point. i don't know how this is distinct from 'ephemeron' tables, so I might be missing something. - Leo On Jul 3, 2010, at 12:00 PM, [email protected] wrote: > Send es-discuss mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://mail.mozilla.org/listinfo/es-discuss > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of es-discuss digest..." > Today's Topics: > > 1. Re: We need to name "EphemeronTable" (was: Do we need an > experimental extension naming convention?) (Brendan Eich) > 2. Re: We need to name "EphemeronTable" (was: Do we need an > experimental extension naming convention?) (P T Withington) > > From: Brendan Eich <[email protected]> > Date: July 2, 2010 10:01:26 PM PDT > To: Mark S. Miller <[email protected]> > Cc: "[email protected]" <[email protected]>, Erik Arvidsson > <[email protected]> > Subject: Re: We need to name "EphemeronTable" (was: Do we need an > experimental extension naming convention?) > > > On Jul 2, 2010, at 7:45 PM, Mark S. Miller wrote: > >> I'm also in favour of a regular Map and Set. Also a dense List (i.e., what >> we might have otherwise called an Array :(.) However, the history of oo >> class libraries shows collection libraries to be a tarpit, so I'm unwilling >> to take the lead on this issue. If someone else would like to, so long as >> they keep it bloody simple (i.e., not like Java, Smalltalk, or STL), that'd >> be great. Even the E collections >> <http://erights.org/elang/collect/tables.html> >> <http://erights.org/javadoc/org/erights/e/elib/tables/EMap.html>, where I >> could make them as simple as I wished, got way too complicated -- more >> complicated than I would find acceptable. >> >> Great designers of extraordinarily simple expressive APIs, please step >> forward! > > Ideally TC39 should not standardize or design anything not already proven and > popular (if not dominant) in the field. The problem is no one can make > practicaly O(1) collections without Object.hashcode and Object.identity. > > Say we add hashcode and identity. Then we'll have to wait a while, Could we > bootstrap Set, Map, and WeakMap and call it enough? I think so. > > "Dense List" could be added but implementations are optimizing for dense > arrays already. I think this one is too close to Array to be worth it, but > without a detailed design that's just my gut reaction. FWIW. > > /be > > > > From: P T Withington <[email protected]> > Date: July 3, 2010 4:47:50 AM PDT > To: Brendan Eich <[email protected]> > Cc: "Mark S. Miller" <[email protected]>, Erik Arvidsson > <[email protected]>, "[email protected]" <[email protected]> > Subject: Re: We need to name "EphemeronTable" (was: Do we need an > experimental extension naming convention?) > > > Coming late to the party: 'alias' might be intuitive (from it's dictionary > definition and use in filesystems as a non-preserving way to give an > alternate name). > > On 2010-07-03, at 00:57, Brendan Eich wrote: > >> On Jul 2, 2010, at 8:58 PM, David Herman wrote: >> >>>> Cool. I'm warming to WeakMap as well. Do we have any objections to WeakMap? >>> >>> +1 >>> >>> I <3 WeakMap. >> >> The Force is strong with WeakMap! ;-) >> >> +1 or more >> >> /be >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss > > > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss
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