At 7:37 PM +0200 4/5/00, Ralf Muschall wrote:
>Where does the habit to use "flip (.)" in many FP people come
>from?
It's useful for composing several functions in pipeline fashion.
Simon Thompson (in his book _Haskell: the Craft of Functional Programming_)
defines a "forward composition" operator:
(>.>) :: (a->b) -> (b->c) -> (a->c)
(>.>) = flip (.)
A composition using this operator, e.g.,
f >.> g >.> h
is easily understood as a pipeline in which data flows from left to right.
Using ordinary composition (.), the same function would be written
h . g . f
which can be thought of as a pipeline only if one imagines data flowing
right to left.
--HR
------------------------------------------------------------------
Hamilton Richards Jr. Department of Computer Sciences
Senior Lecturer Mail Code C0500
512-471-9525 The University of Texas at Austin
SHC 434 Austin, Texas 78712-1188
[EMAIL PROTECTED]
------------------------------------------------------------------
