Jordan the purpose of `Array.from` is to iterate over the string, and the point of iteration instead of splitting is to have automagically codepoints. This, unless I've misunderstood Mathias presentation (might be)
So, here there is a different problem: there are code-points that do not represent real visual representation ... or maybe, the real problem, is about broken `Array.from` polyfill? I wouldn't be surprise in such case ;-) On Thu, Apr 2, 2015 at 1:22 AM, Jordan Harband <[email protected]> wrote: > Unfortunately we don't have a String#codepoints or something that would > return the number of code points as opposed to the number of characters > (that "length" returns) - something like that imo would greatly simplify > explaining the differences to people. > > For the time being, I've been explaining that some characters are actually > made up of two, and the [image: 💩] character (it's a fun example to use) > is an example of two characters combining to make one "code point". It's > not a quick or trivial thing to explain but people do seem to grasp it > eventually. > > On Wed, Apr 1, 2015 at 4:09 PM, Andrea Giammarchi < > [email protected]> wrote: > >> and now I also gonna hope that `Array.from(foo).length // 2` wasn't by >> accident, instead of `bar` ... >> >> On Thu, Apr 2, 2015 at 1:07 AM, Andrea Giammarchi < >> [email protected]> wrote: >> >>> ```js >>> foo.length; // 2 >>> Array.from(foo).length // 1 >>> >>> bar.length; // 2 >>> Array.from(bar).length // 2 >>> ``` >>> >>> I know already everything you wrote ... now, how to explain to JS users >>> out there and how to solve? >>> >>> On Thu, Apr 2, 2015 at 1:04 AM, Boris Zbarsky <[email protected]> wrote: >>> >>>> On 4/1/15 6:56 PM, Andrea Giammarchi wrote: >>>> >>>>> Why is that >>>>> >>>> >>>> Because those are different things. The first is a single Unicode >>>> character that happens to be represented by 2 UTF-16 code units. The >>>> second is a pair of Unicode characters that are each represented by one >>>> UTF-16 code unit, but also happen to form a single grapheme cluster >>>> (because one of them is a combining character). To complicate things >>>> further, there is also a single Unicode character that represents that same >>>> grapheme cluster.... >>>> >>>> String length shows the number of UTF-16 code units. >>>> >>>> Array.from works on Unicode characters. That explains the foo.length >>>> and Array.from(foo).length results. >>>> >>>> and how to solve? >>>>> >>>> >>>> Can you clearly explain what problem you are trying to solve? >>>> >>>> -Boris >>>> >>>> _______________________________________________ >>>> 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 >> >> >
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