On May 16, 2011, at 2:19 PM, Mark Davis ☕ wrote:
> I'm quite sympathetic to the goal, but the proposal does represent a
> significant breaking change. The problem, as Shawn points out, is with
> indexing. Before, the strings were defined as UTF16.
Not by the ECMAScript specification
>
> Take a sample string "\ud800\udc00\u0061" = "\u{10000}\u{61}". Right now, the
> 'a' (the \u{61}) is at offset 2. If the proposal were accepted, the 'a' would
> be at offset 1.
It the string is written as \ud800\udc00\u0061" the 'a' will be at offset 1,
even in the new proposal. It would only be at offset 1 if it was written as
"\u+010000\u+000061" (using the literal notation from the proposal).
> This will definitely cause breakage in existing code;
How does this break existing code. Existing code can not say
"\u+010000\u+000061". As I've pointed out elsewhere on this thread existing
libraries that do UTF-16 encoding/decoding must continue to do so even under
this new proposal.
> characters are in different positions than they were, even characters that
> are not supplemental ones. All it takes is one supplemental character before
> the current position and the offsets will be off for the rest of the string.
Allen
_______________________________________________
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
