On Tue, Oct 29, 2013 at 10:08 AM, Brendan Eich <[email protected]> wrote:
> Tristan Zajonc wrote: > >> >> It's true that in JS today, comparing an object to a non-object, >> valueOf or toString on the object can be used to make == results vary. >> >> However, I'm proposing value objects with declarative syntax to >> solve several problems: >> >> 1. Backward compatibility, so == uses cannot change unexpectedly >> on extant code, or grow performance hair in existing engines >> facing existing code. >> >> 2. Solve the cross-frame problem where loading the same value >> class declaration results in the same typeof and other results for >> operations on values instantiated from equivalent declarations >> (details still being worked out). >> >> 3. Facilitate functional programming, both for user benefit and >> for engines, which can better optimize based on immutable values >> (including stack allocation). >> >> >> On 3, I think mutability is a required option for matrix libraries. >> While immutable matrix APIs are interesting, I do not believe anybody has >> successfully implemented a flexible high performance immutable matrix >> library in any language. I think the key user demand is porting basic >> MATLAB like numeric code to JS, which wouldn't be possible with an >> immutable library. >> > > The Haskell folks will disagree with you, but I'll let them speak for > themselves. > > My point here is only that I don't think JS should adjudicate this debate in the context of operators. It seems like this discussion should happen if a Matrix type is added to the core of JS. Having operators would encourage the development of cow paths. > Item 2 is important but hard to get right in the face of mutable objects > and prototype chains. > > I don't understand this issue well enough to comment. > > Can value objects / immutability be separated from operator overloading? >> > > Almost certainly. I'm starting with value objects because in design, > leaving things out (without necessarily being future-hostile to extension) > is generally better than trying to do include too much. > > The value class syntax (operator multimethods) that I showed at JSConf.eu > could easily be class syntax, as you surmised. Got it. I'm a fan of the syntax and dispatch mechanism.
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
