Brandon S. Allbery KF8NH wrote:
On Mar 23, 2010, at 13:39 , Ertugrul Soeylemez wrote:
layout-style syntactic sugar for function application. Here is an example of what it might look like:
function $$ anArgument sin (x^2) anotherArgument f $ x + 3
Doesn't layout already do this?
function arg1 arg2 arg3
The layout rule is only triggered by a limited set of keywords (like do, where, let, ...), and Ertugrul's proposal is to add a keyword for function applicaton to this set. I like this idea, because it would enable non-monadic embedded DSLs to use layout. For example, consider setting properties in wxHaskell: layoutSet myButton $$ text := "Ok" on action := doSomething instead of set myButton [ text := "Ok" , on action := doSomething ] Of course, this would need some type hackery à la PrintF to make set accept multiple arguments, and the proliferation of such type hackery may seem unfortunate. On the other hand, the hackery could possibly be encapsulated in a combinator like polyvariadic :: Poly a b c => ([a] -> b) -> c so that layoutSet can be implemented as layoutSet widget = polyvariadic (set widget). Tillmann