Hello everyone, I made a formal proposal https://github.com/Jack-Works/proposal-Number.range , welcome to disscuss the details in the repo!
On Thu, Nov 29, 2018 at 3:01 PM Jordan Harband <[email protected]> wrote: > It's not a "standard library" unless every part of it has gone through a > full standards process. > > On Wed, Nov 28, 2018 at 8:31 PM Jacob Pratt <[email protected]> wrote: > >> I'm not saying we should add it on to that proposal, but rather saying >> that I think more effort should be put into a standard library where things >> like this don't need to go through a full standards process. That's just my >> opinion, and borderline on-topic for this specific suggestion. >> >> I'm absolutely in favor of having a `range` method, it's just _where_ it >> should be that I differ. >> >> Jacob Pratt >> >> On Thu, Nov 29, 2018 at 4:29 AM Jack Works <[email protected]> wrote: >> >>> Oh, I'm not here to find out how to implement a range in detail. That's >>> the trivial things, I want to first make it become a stage 0 proposal, then >>> we can discuss if we need some overload or how to deal with the edge cases. >>> Ps, does Pratt mean we should add it as a standard library in the stage >>> 1 standard libraray proposal? >>> >>> On Thu, Nov 29, 2018, 12:18 Jacob Pratt <[email protected]> wrote: >>> >>>> Quick, simple TypeScript range function (with overloads, of course). >>>> >>>> ``` >>>> export function range(end: number): IterableIterator<number>; >>>> export function range(start: number, end: number): >>>> IterableIterator<number>; >>>> export function range(start: number, end: number, step: number): >>>> IterableIterator<number>; >>>> export function* range(start: number, end?: number, step?: number): >>>> IterableIterator<number> { >>>> // overload #1 >>>> if (end === undefined) { >>>> [start, end, step] = [0, start, 1]; >>>> } >>>> >>>> // overload #2 >>>> if (step === undefined) { >>>> step = Math.sign(end - start); >>>> } >>>> >>>> // ensure we have the appropriate types >>>> if (typeof start !== 'number' || typeof end !== 'number' || typeof >>>> step !== 'number') { >>>> throw new TypeError('all parameters must be of type number'); >>>> } >>>> >>>> while ((start < end && step > 0) || (start > end && step < 0)) { >>>> yield start; >>>> start += step; >>>> } >>>> } >>>> ``` >>>> >>>> IMO, we should focus on building up a JavaScript standard library that >>>> has tons of useful utilities like this, rather than continue to add methods >>>> onto namespaces. Perhaps that's just me, though. >>>> >>>> Jacob Pratt >>>> >>>> On Wed, Nov 28, 2018 at 9:33 PM Tab Atkins Jr. <[email protected]> >>>> wrote: >>>> >>>>> I end up writing a range function in virtually every project I use, so >>>>> yeah, I think this is worthwhile. >>>>> >>>>> My own preferences, based on Python precedence: >>>>> >>>>> Number.range(end) === Number.range(0, end, 1) >>>>> Number.range(start, end) === Number.range(start, end, >>>>> Math.sign(end-start)) >>>>> Number.range(start, end, step) => { >>>>> if start < end && step > 0: yield all (start + k*step), for k from 0 >>>>> to infinity, less than end >>>>> elif start > end && step < 0: yield all (start + k*step), for k from >>>>> 0 to infinity, greater than end >>>>> else: yield nothing >>>>> } >>>>> >>>>> So: >>>>> * [...Number.range(5)] evaluates to [0, 1, 2, 3, 4] >>>>> * [...Number.range(0)] evaluates to [] >>>>> * [...Number.range(-5)] evaluates to [] >>>>> * [...Number.range(1, -3)] evaluates to [1, 0, -1, -2] >>>>> * [...Number.range(-3, 1)] evaluates to [-3, -2, -1, 0] >>>>> * [...Number.range(1, 1)] evaluates to [] >>>>> * [...Number.range(0, 10, 5)] evaluates to [0, 5] >>>>> * [...Number.range(0, 10, -5)] evaluates to [] >>>>> >>>>> ~TJ >>>>> >>>> _______________________________________________ >>>>> 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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