I am very new to Haskell, but what I've discovered so far is that the
application operator $ is used to improve code readability. It can
sometimes be used eliminate the need for parentheses that break
natural left-to-right reading.
Hoogle covers an example:
http://hackage.haskell.org/packages/archive/base/latest/doc/html/Prelude.htm...
Cheers!
On Tue, Aug 21, 2012 at 1:34 PM, Carlos J. G. Duarte
Hi. Often I see the following pattern to build function "pipelines":
x = f1 . f2 $ fn arg
They use the "$" just before the last function call. I never got much into it: when to use the "." or the "$"? I think today I figured it out: => "." is a function composition operator: used to "merge" functions; => "$" is a function application operator: used to apply a function to its arguments.
If this reasoning is correct, I think the following should be a more adequate pattern:
x = f1 . f2 . fn $ arg
To merge/compose all functions first and apply the composed function to its parameter(s). Am I correct on this? Thx
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