bracketOnError, while, forever
rturk at science.uva.nl
Wed Feb 9 19:32:12 EST 2005
On Wed, Feb 09, 2005 at 08:47:43PM +0100, Tomasz Zielonka wrote:
> On Wed, Feb 09, 2005 at 11:50:48AM -0000, Simon Marlow wrote:
> > sortBy (comparing fst)
> > is just too cute not to have. Any objections?
> How about a more general function:
> composeFGxGy :: (b -> b -> c) -> (a -> b) -> a -> a -> c
> composeFGxGy f g x y = f (g x) (g y)
I agree, though I don't like its name ;) Mike just called it
`onField', and I've seen it as `on' before.
sortBy (compare `on` fst)
groupBy ((==) `on` toLower)
zipWith ((*) `on` fst)
Having both `comparing' and `equaling' seems overkill, and just
`on' is just as usable IMO. (No, I never used that last one.)
Nobody can be exactly like me. Even I have trouble doing it.
More information about the Libraries