When should I use $ (and can it always be replaced with parentheses)?

Question

From what I\'m reading, $ is described as \"applies a function to its arguments.\" However, it doesn\'t seem to work quite like (apply ...) in Lisp

Answer 1

You're mostly understanding it right---that is, about 99% of the use of $ is to help avoid parentheses, and yes, it does appear to be preferred to parentheses in most cases.

Note, though:

> :t ($)
($) :: (a -> b) -> a -> b

That is, $ is a function; as such, it can be passed to functions, composed with, and anything else you want to do with it. I think I've seen it used by people screwing with combinators before.