8 Jun
2013
8 Jun
'13
1:35 p.m.
On Sat, Jun 8, 2013 at 9:02 AM, Peter Hall
This is confusing me, and I'm wondering if it's a compiler bug. I have this:
foo = (++) `on` show
I'm expecting the type to be:
foo :: Show a => a -> a -> String
But GHCI is inferring:
foo :: () -> () -> String
No bug; it's the monomorphism restriction combining with extended defaulting to infer a monomorphic type. If you want to keep the monomorphism restriction and throw a type error, disable ExtendedDefaultRules. -- brandon s allbery kf8nh sine nomine associates allbery.b@gmail.com ballbery@sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net