[Haskell-cafe] Should `(flip (^^))` work?

wren ng thornton wren at freegeek.org
Mon Sep 15 23:27:35 EDT 2008

Mauricio wrote:
> Hi,
> I tested the expression below
> and it doesn't work. Is there
> some way to achieve that (i.e.,
> turning an expression inside
> parenthesis into an operator)?
> 2 `(flip (^^))` (3%4)

Another solution if you don't like defining extra (-|) and (|-) 
operators is:

   > ($2) (flip (^^)) (3%4)

The right section of function application is type lifting. The general 
form of this construction is:

   > ($x) (f a b c...) y z...

Which is equal to (f a b c... x y z...). That is, the construction lets 
you raise any argument out to before the function, thus making the 
partially applied function into an infix between |x| and |y x...|.

Live well,

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