On Aug 30, 2013, at 10:13 AM, David Herman <[email protected]> wrote:
> On Aug 30, 2013, at 9:39 AM, Allen Wirfs-Brock <[email protected]> wrote: > >> I think the right-way to think about structs is as an record structure with >> no properties fixed behavior provided by a "wrapper". Very similar to the >> ES primitives except that structs can be mutable. The way to associate >> properties with structs is to encapsulate them in an object, preferably via >> a class definition. If we go that route we can reach the point where ES >> classes have fixed-shape internal state defined as-if by a struct. > > I might give a slightly different angle on this, and describe structs as > objects with a fixed template for their own properties. They are still > objects, they still inherit from prototypes. But they have a predefined set > of own properties. > >> Typed Arrays are a different beast that already exist in the real world. I >> don't see any need for consistency between Typed Arrays and struct types. >> Consistency between Typed Arrays and Array is more important. > > Mostly agreed, except I'd just refine that to say there's no need for > consistency *in this dimension*. It would be a shame if typed arrays weren't > generalized by the typed objects API in general, and I worked hard to make > the pieces fit together. That nuance aside, the fact that, in practice, > arrays are patched with additional properties (in fact, IIRC the ES6 template > strings API adds properties to arrays) suggests that non-extensibility would > be a real incompatibility between arrays and typed arrays. So I'm cool with > making typed arrays -- but not structs -- extensible. I think of TypedArrays as being Arrays of structs with a fixed type/shape - the Array itself is a regular object with regular property characteristics, whereas the individual elements are all value types . For example, say i have a struct type S, and make a regular Array filled with S. Aside from the poor performance, this is now essentially what a typed array of structs is. What is the reason for making the fast version of an array of structs lose the features of a regular array filled with structs? --Oliver > > Dave > > _______________________________________________ > 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
