`String.prototype.symbolAt()` (improved `String.prototype.charAt()`)

Brendan Eich brendan at mozilla.com
Sat Oct 19 12:11:33 PDT 2013

Allen Wirfs-Brock wrote:
> The use case that we don't support well is any sort of back wards iteration of the characters of a string. We don't current have an iterator specified to do it, nor do we have a one stop way to test whether we at looking at the trailing surrogate of a surrogate pair.

What do you mean by "one stop"? O(1)? We aren't going to mandate 
implementations make such tests (or backward iteration) that cheap.

Is there yet a real world (from the field, not a testcase) use-case for 
backward iteration?


More information about the es-discuss mailing list