Thank you for renaming padLeft/padRight to padStart/padEnd. On the treatment of code units, I was hoping to find more detail in the meeting minutes, but haven’t seen those yet. The native encoding of strings in the language, with the exception of a few parts that we haven’t been able to fix in EcmaScript 2015, is UTF-16, in which some characters take one code unit and others two code units. The current padStart/padEnd proposal doesn’t take that into consideration – it truncates at code unit boundaries rather than code point boundaries, and thus perpetuates problems stemming from obsolete assumptions about Unicode from 1995.
For background on the Unicode problems in pre-2015 EcmaScript see: https://mathiasbynens.be/notes/javascript-unicode and the proposed solution that got integrated into EcmaScript 2015: http://norbertlindenberg.com/2012/05/ecmascript-supplementary-characters/ Thanks, Norbert > On Nov 17, 2015, at 13:07 , Jordan Harband <[email protected]> wrote: > > In the TC39 meeting today, we discussed these concerns and decided to rename > the proposal from padLeft/padRight to padStart/padEnd > (https://github.com/tc39/proposal-string-pad-start-end/commit/35f1ef676f692bfc1099f9ed7c123bd2146f9294) > - and correspondingly, to investigate providing trimStart/trimEnd (alongside > the legacy trimLeft/trimRight). The consensus remained the same around > treatment of code units - which is that, like every other string method, they > should conform to the native encoding of strings in the language. > > As such, the proposal has now been approved for stage 3 in the TC39 process. > > Thanks everyone for providing your input! > > - Jordan > > On Mon, Nov 16, 2015 at 10:59 AM, Mohsen Azimi <[email protected]> wrote: > I might be late to this but please don't use "left" and "right" for referring > to start and end of a string. In right to left languages it's confusing. As > someone who writes right-to-left we have enough of those "left" and "rights" > based on English writing direction. CSS made this mistake but corrected it in > later specs. Original box model (margin and padding) used left and right but > newer flex box spec uses start and end. Because we made a mistake in the past > we don't have to repeat it. > > Thanks, > Mohsen Azimi > > On Mon, Nov 16, 2015 at 10:44 AM Claude Pache <[email protected]> wrote: > > > Le 16 nov. 2015 à 14:01, Alexander Jones <[email protected]> a écrit : > > > > I see about as little use case for this as `String.prototype.blink`. > > Date/hours is better solved with zero padding formatting, not just padding > > out the already stringified number (think negative values -000042). Same > > applies to filenames for lexicographical sort. Fixed length fields in wire > > protocols already need to be converted to bytes first before padding, which > > makes the use of this feature impossible. > > Sure, in all those cases I could have used `sprintf` instead of `str_pad`. > However, the equivalent of neither one is natively available in JS. > > I could write a tagged template that does the equivalent of `sprintf`.... And > `.padLeft^H^H^H^HStart` and `.padEnd` would be nice to have for writing more > easily such a template,... oh well... :-/ > > —Claude > > > > > > > On Monday, 16 November 2015, Claude Pache <[email protected]> wrote: > > Here are my typical use cases (found by scanning uses of "str_pad" in my > > PHP codebase): > > > > * transferring data through a protocol that uses fix-length fields; > > * formatting things like date/hours, e.g. "08:00" for "8am"; > > * generating filenames of fixed length, so that they sort correctly, e.g. > > "foo-00042.txt"; > > * generating codes of fixed length (e.g. barcodes). > > > > In all those cases, the set of characters is typically limited to ASCII or > > ISO-8559-1. > > Moreover, the filler string consists always of one ASCII character (usually > > " " or "0"). > > > > —Claude > > > > _______________________________________________ > > 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 > > _______________________________________________ > 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 _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
