Ranges

Viktor Kronvall viktor.kronvall at gmail.com
Thu Nov 3 20:18:50 UTC 2016


Actually, after giving it some more thought for that case there is just
that one possibility that makes sense.

However, there are more ambiguous cases such as `String.range("AAA",
"ZZZ")` (should all letters increase at once or should the rightmost letter
be incremented first)

Also, how would range handle the arguments in inverted order? Should there
be a decreasing range or should it terminate with no elements in the
iterator?
2016年11月3日(木) 21:05 kdex <kdex at kdex.de>:

> About the code points: `String.range` should also handle surrogate pairs,
> similar to for..of does it.
> About `String.range("A", "zzz")`: Do any other possibilities even make
> sense?
>
> On Thursday, November 3, 2016 6:47:04 PM CET Viktor Kronvall wrote:
> > For `String.range` what would the expected result of
> > `String.range('A','zzz')` be?
> >
> > Is an exhaustive pattern expected?
> >
> > `['A','B','C',...'Z','a','b','c',...,'z','AA','AB',...]`
> > 2016年11月3日(木) 19:21 Michael J. Ryan <tracker1 at gmail.com>:
> >
> > > If there's a Number.range, if suggest a corresponding String.range for
> > > character ranges...  Agreed on it being a utility function over me
> syntax.
> > >
> > > On Nov 3, 2016 10:25 AM, "Isiah Meadows" <isiahmeadows at gmail.com>
> wrote:
> > >
> > > If string ranges are based on character codes, it will (for the Latin
> > > alphabet, at least, not necessarily for other languages).
> > >
> > > I would prefer a function over syntax, though, since it would be more
> > > easily adopted (polyfill > syntax), and it would fit more idiomatically
> > > with the rest of the language (which also uses functions for most
> > > utilities).
> > >
> > > Maybe a `Number.range` would work?
> > >
> > > ```js
> > > Number.range = function *range(start, end=undefined, step=1) {
> > >   if (end === undefined) [start, end] = [0, start];
> > >   if (end === undefined) end = Infinity;
> > >   for (let i = 0; i < end; i += step) {
> > >     yield i;
> > >   }
> > > };
> > > ```
> > >
> > > On Thu, Nov 3, 2016, 12:56 kdex <kdex at kdex.de> wrote:
> > >
> > > Agreed. There's no reason why `Array.range` or `[1..10]` couldn't just
> > > return a generator
> > > or at least something that extends a generator, though. I wonder if
> it's
> > > viable to implement
> > > something akin to `.length` on ranges, which could be natural numbers
> or
> > > `Infinity`.
> > >
> > > As for numbers, I don't see any issues. One issue that came up in the
> > > original thread was
> > > that string ranges may need a better definition, as ["A".."C"] might
> not
> > > necessarily transpile
> > > to be a generator that yields "A", "B" and "C".
> > >
> > > On Thursday, November 3, 2016 4:46:03 PM CET Isiah Meadows wrote:
> > > > I'll note, just for clarity, that Scala's `1 to 10` is technically
> just a
> > > > normal method call equivalent to `(1).to(10)`, with optional
> parentheses
> > > > removed.
> > > >
> > > > Also, I'd prefer this to be a generator instead, so infinite ranges
> are
> > > > also possible, and so it doesn't have to be eager.
> > > >
> > > > On Thu, Nov 3, 2016, 11:52 Hikaru Nakashima <
> oao.hikaru.oao at gmail.com>
> > > > wrote:
> > > >
> > > > > How about this
> > > > >
> > > > > ```
> > > > > for ( i of Array.range(1, 10) ) { ... }
> > > > > // OR
> > > > > for ( i of [1..10] )  { ... }
> > > > > ```
> > > > >
> > > > >
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