Response inline On Sun, Dec 6, 2015 at 12:19 AM, Boris Zbarsky <[email protected]> wrote: > On 12/5/15 8:44 AM, Coroutines wrote: >> >> What I want is to be able to view a String through a typed array >> without duplicating the memory/contents of that string. > > > The big problem with this is that the actual in-memory representations of > strings and arraybuffers can be quite different in implementations right > now. > > For example, strings typically have a complicated representation that > involves multiple fragments, ropes, etc, to make string concatenation fast. > Not only that, but to save memory in various engines some strings that only > contain values less than 256 are stored with underlying 8-bit units, not > 16-bit ones. There has also been talk of using something like UTF-8 for the > internal string representation in some engines, to reduce the impedance > mismatch with engine consumers (like a browser rendering engine).
AFAIK most engines already do this. > > Arraybuffers, on the other hand, are typically an actual contiguous chunk of > memory to make access fast. And of course they just exposed whatever bytes > they contain. And V8, if I understand correctly, uses effectively a linked tree (closer to a web) of single-character pairs for their strings. This is not at all contiguous, but makes string slicing and building very cheap to do. The only realistic way to have a string stored in an ArrayBuffer is to have it encoded like a C string (er... `char*`). > > -Boris > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss -- Isiah Meadows _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
