On Tue, Jun 1, 2010 at 6:29 PM, Sam Ruby <[email protected]> wrote: > On 06/01/2010 09:15 PM, Waldemar Horwat wrote: >> I assume that the proposal is that: >> >> const TA = >> Array.newTypedArray(fixed_length, >> Object.newStructType({x:"u32", y:"u32", z:"u32", >> r:"u8", g:"u8", b:"u8", a:"u8"})); >> let a = new TA(...); >> >> b = a[i]; >> a[i].x += 1; >> >> Now b.x also reflects the new value of a[i].x; i.e. b is an alias, not a >> mutable copy. > > That's a valid choice, but one that can't be applied 100% consistently. For > example, wouldn't the following create a mutable copy? > > a[0] = b;
The way this works in js-ctypes is that b = a[i]; causes b to be a struct object that aliases part of the array a; and a[0] = b; copies an element from a[i] to a[0]. Neither creates a mutable copy in a new buffer. > I'll also assume that all aliases will pin the entire array for the purposes > of garbage collection. This is how js-ctypes does it. > I'll still maintain that the choice that ECMA 334 takes, namely > that the assignment to b in the example above, makes a mutable > copy is a valid choice. I would expect a[0].x = 3; to modify a[0], not a temporary copy of a[0]. How do you propose to make that work in ES? -j js-ctypes: https://wiki.mozilla.org/Jsctypes/api _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
