partial application

[Pixel]

Koen Claessen <koen@cs.chalmers.se> writes:

[...]

>   ... (\x -> f x 2 3) ...
> 
> This seems rather ugly, since the order of arguments in a
> function plays a crucial role. For example, the map function
> takes the list as its second argument, since it is so much
> more common to partially apply map with the function rather
> than the list.

For sure the order of arguments play a crucial role in MLs.
I don't know many other syntax:

- merd http://merd.net/choices_syntax.html#function_calls 
   f(1, 2, ) is (f 1 2)
   f(, 2, 3) is (\x -> f x 2 3)

- OCaml's labels http://caml.inria.fr/ocaml/htmlman/manual006.html
   f ~y:2 ~z:3 is (\x -> f x 2 3)

- Pop-11 http://www.cs.bham.ac.uk/research/poplog/primer/node96.html
   f(% 2, 3 %) is (\x -> f x 2 3)

I'm interested in other syntaxes...
 
> For 2-argument functions, the sections notation might help:
> 
>   (1 `f`)         -- === (f 1) === (\y -> f 1 y)
>   (`f` 2)         -- === (\x -> f x 2)

I never thought of this :)

Of course it also works with more than 2-argument functions when you want to
partially apply only the 2 second argument:

   (`f` 2) 1 3

> In a distant past, Erik Meijer and I experimented with
> introducing the syntax:
> 
>   (f 1 2 _)
>   (f 1 _ 3)
>   (f _ 2 3)
> 
> But it became all very clumsy.

do you have more info on this?