On Nov 16, 2015, at 0:18 , Jordan Harband <[email protected]> wrote: > 1) The primary use cases in my opinion are monospaced command line output, or > preformatted text output in a webpage.
These both make assumptions about font rendering: One glyph per Unicode character, each glyph the same width. ECMAScript is used in a wide range of applications where these assumptions do not hold, and baking them into API causes problems. I think API that primarily is intended for, and limited to, these use cases should be part of libraries for these use cases. > 2) ECMAScript only has two concepts: code units, and code points - it does > not handle grapheme clusters, and if it were to add support for this, these > proposed methods could be adapted to handle them in the same way as all of > the pre-existing string methods. The issue of code units versus code points > has been resolved in > https://github.com/tc39/proposal-string-pad-left-right/issues/5 to the > satisfaction of the designated spec reviewers and the spec editor. The conclusion on issue 5 apparently is: 1) Some other programming languages provide functions that are partially broken, so ECMAScript can do the same. 2) Supporting a correct solution “would greatly complicate the algorithm”. In the two years that I attended TC39 meetings (2011-2013), such arguments were rarely made, and I don’t think they ever ended the discussion. Careful analysis of use cases and in particular of edge cases was the norm. > 3) The naming is set in stone - `reduceRight` sets a clear precedent that > "right" is "the length minus one", and has no relationship to the visual > direction, and based on `trimLeft` and `trimRight`, which are already > implemented in basically all browsers Thus, in ECMAScript, "left" is not > considered a visual direction but rather a synonym for "start" and "index 0". > The naming is also mentioned here: > https://github.com/tc39/proposal-string-pad-left-right#naming A stage 1 proposal isn’t set in stone. As Claude pointed out, reduceRight is not a good precedent because arrays have no visual order. The content of strings is commonly associated with a visual order, and that visual order is often not the same as the logical order. > 4) Per your second question and > https://github.com/tc39/proposal-string-pad-left-right/issues/5, this is > intentionally not a concern of this proposal. Per 2) above, it is. _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
