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Currying makes positional only parameters look cooler and fancier. It's a trap. Labeled arguments is the way to go for 99% of all parameters. Accidental currying is horrible.

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If you look at how people actually write PureScript, which is much like Haskell, but with anonymous records, you can see that they're not actually used 99% of the time.

I write quite a bit of Elm and I use currying a lot. I really wish it was explicit. Or at least that my IDE could highlight them.

Could you share an example?

This function would use an anonymous record:

    splitString :: { pattern :: String, string :: String } -> Array String
    splitString { pattern, string } = ...

This function would use positional arguments:

    splitString :: Pattern -> String -> Array String
    splitString pattern string = ...

https://github.com/purescript/documentation/blob/master/lang...

Somewhat related - be wary of implicit parameter passing in function pipelines. For example, Try ['10', '10', '10'].map(Number.parseInt) in your browser console. What's actually being called is:

Number.parseInt('10', 0) Number.parseInt('10', 1) Number.parseInt('10', 2)

Typing fixes this, and anonymous records make it even better.

JavaScript lacks typing, and then they decided on a weird signature for the callback...

Unfortunately typing doesn't fix this. The 2nd callback function argument of Array.map is (index:number), and the 2nd argument of Number.parseInt is (radix:number).

It's a very nasty issue to debug.

If there were typing, there would be no reason to not use newtypes[0] for radix and index. These values should only be explicitly unwrapped to plain numbers.

It would look like this

    newtype Radix = Radix { radixToWord :: Word }
    newtype Index = Index { indexToWord :: Word }

[0]: https://wiki.haskell.org/Newtype

One of my favorite features in OCaml is labeled arguments. You get a similar flavor of partial application, but without the strict argument order requirement (most of the time -- higher order functions are strict about labeled-function arguments).

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