CrossEye

I wonder if whatever is left of Netscape can sue Microsoft now over JScript...

And many of us have gained a great deal by having you publish on the side.

Thanks, raganwald!

Ok, that helps make it a bit more palatable to me.

Thanks for the information.

One question, though: How do user functions interact in here? If you didn't include `flatten`, but I had my own version of it, would it be straightforward for me to build `process` using my own `flatten`? Do I have to modify some Trine objects, or can I use some simple function references?

Obviously I haven't yet actually dug into the Trine code. Perhaps this weekend.

as inglor said, this depends on strict mode:

    > var isboxed = (function() {"use strict"; return function isboxed() {return this instanceof Number;}}());
    > isboxed.call(5);
    false

That is ceratainly one of my standard examples.

The best answer to this seems to be simply:

    var sum = ls => ls.reduce(add, 0)

ISTM that this is neither as elegant nor as easy to reason about, but it's also not horrible. It really moves away from the easy association that Ramda makes between

    var currentTotal = reduce(add, 0, nbrs);

and

    var sum = reduce(add, 0); //=> :: [Number] -> Number

Of course this arrow syntax is ES6 (or transpiler) only, but the library is predicated on that notion. Ramda is a bit of an oddity, still maintaining compatibility with ES3 - ES6.

No, in fact the real problem has been that too many incompetent people were far too certain about how to use it.

The difference starts to show when you want to partially apply some values.

    // process1 :: (Item -> Bool) -> [Item] -> [OtherType]
    // process2 :: [Item] -> [OtherType]
    process1(isOk, items); //=> [otherType1, otherType2, ...]
    process2(items); //=> [otherType1, otherType2, ...]

    
    var processR1 = seq(filter, map(toOtherType), flatten);
    var processR2 = processR1(isOk);

    
    var processT1 = (isOk, items) => items.filter(isOk).map(toOtherType).flatten()
    var processT2 = items => processT1(isOk, items)

That's why I'm wondering if there's some easier way to do this.

That's not sad. Use the tools that work for you.

It was finding that those tools were no longer supporting the way I wanted to work that got me started on Ramda. I'm guessing the same is true for the author of Trine.

(Disclosure: one of the authors of Ramda here, so I may well be biased toward a very different approach.)

This is an interesting approach, but I get caught right at the beginning, where you say "What you'd really want to do is this:

    items
      .filter(isOk)
      .map(toOtherType)
      .flatten()
      
      

But what I really want to do is build a reusable function:

    var process = seq(filter(isOk), map(toOtherType), flatten);
    

So I can at my leisure call

    process(items);
    

Or later put `process` in another sequence, or do something like:

    map(process, groupsOfItems)
    

And I don't see that Trine helps with that. Am I missing the way to use Trine to build functions, or do I simply have to wrap up a Trine construct in a function that takes a parameter, does its Trine magic, and returns that result?

"governments and private companies" certainly do not preclude committees. Quite to the contrary, in fact.

Disclosure: self-submission

Yes, and those damned Italians still refuse to switch to English too!