Clamp

[ccorcos]

#1563

R.clamp(1, 10, -1) // => 1
R.clamp(1, 10, 11) // => 10
R.clamp(1, 10, 4)  // => 4

[davidchambers]

Should we throw if min > max?

[ccorcos]

good idea

[ccorcos]

done

[davidchambers]

This should read min must not be greater than max. ;)

[ccorcos]

done

[ccorcos]

hmm. not sure whats going on here with that error...

[davidchambers]

In order to appease the linter, you'll need to write this like so:

if (...) {
  ...
}

[ccorcos]

I see. done

[ccorcos]

ok @davidchambers, added some tests for letters as well. I'm not sure what you want to do about ./shared/eq though since it doesnt exist. I could import ../src/equals instead.

[davidchambers]

@ccorcos, see test/shared/eq.js. ;)

[ccorcos]

Hmm. I'm confused. Did I fork off of 0.14?! https://github.com/ccorcos/ramda/blob/master/package.json#L27

I'll have to rebase when I get home.

[davidchambers]

You'll need to update your fork's master branch:

$ git checkout master
$ git pull upstream master
$ git push origin master

[ccorcos]

awesome. done.

[davidchambers]

Shall we mention that this function applies to any type which supports ordering?

[ccorcos]

Sure: how about this?

Clamps any type that supports ordering within a range.

[davidchambers]

In light of #1578 we should probably devote one sentence to the common case and one sentence to the abstraction. What do you think, @CrossEye?

[CrossEye]

Yes, I agree.

Restricts a number to be within a range.

Also works for other ordered types such as Strings and Dates.  (see Type::Ord)

That last bit it just a bit of fantasy, but something I'd love to be able to support.

[ccorcos]

done

[ccorcos]

Alright, so what do you guys think? My first Ramda contribution? :)

[davidchambers]

Looks good, aside from the two outstanding issues:

• (see Type::Ord) should be removed; and
• the empty line at the top of test/clamp.js should be removed.

Once you've addressed these minor issues I'll happily merge this pull request. :)

[CrossEye]

🌿, once those minor changes are made.

[ccorcos]

Boom 🌿

[CrossEye]

Thank you very much!

[davidchambers]

🌳 Thanks for persevering. :)

[ccorcos]

Of course 👍 I look forward to contributing more now that I got the first one out of the way.

[xgrommx]

About clamp maybe it will be more general?

const clamp = curry((min, max, value) => Math.max(min, Math.min(max, value)));

Also if you add clamp why not lerp?

const lerp = curry((start, end, alpha) => start*(1-alpha)+end*alpha

It is linear interpolation https://en.wikipedia.org/wiki/Linear_interpolation http://codepen.io/ma77os/pen/KGIEh

[CrossEye]

@xgrommx:

About clamp maybe it will be more general?

Perhaps I'm misunderstanding. The current implementation handles that case, but should work with any ordered type.

Also if you add clamp why not lerp?

While that is certainly a useful function, my first thought is that it belongs in The Cookbook instead. I certainly would not object to hearing arguments to the contrary though if you disagree.