On May 27, 2007, at 17:23 , Andrew Coppin wrote:
Personally, I try to avoid ever using list comprehensions. But every now and then I discover an expression which is apparently not expressible without them - which is odd, considering they're only "sugar"...
They are. But they're sugar for monadic operations in the list monad, so you have to use (>>=) and company to desugar them. [x | filter even x, x <- [1..10]] becomes do { x <- [1..10]; return (filter even x) } becomes ([1..10] >>= return . filter even). (Aren't you glad you asked?) -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH