[Haskell-beginners] ($) operator

[Brent Yorgey]

On Sun, Jan 25, 2009 at 05:34:35AM +0000, John Hartnup wrote:
> 2009/1/24 Brent Yorgey <byorgey at seas.upenn.edu>:
> 
> >
> >  map ($5) [(+1), (^2), abs]
> >
> > which evaluates to [6,25,5].
> >
> 
> Just to check I understand correctly - you're using ($) to 'promote'
> an expression into a function, in order that it may be used in higher
> order functions?

In this case, I'm using ($) to *make* a higher-order function---($5)
is a function which takes its argument (which must be a function) and
applies it to 5.  (I'm assuming you're familiar with 'operator
sections', if you aren't I can explain that too.)

-Brent