2 May
2011
2 May
'11
10:03 p.m.
On Mon, May 2, 2011 at 6:20 PM, C Rodrigues
I was experimenting with using GADTs for subtyping when I found something interesting. Hopefully someone can satisfy my curiosity. Here are two equivalent GADTs. My understanding was that GHC would translate "Foo" and "Bar" into isomorphic data types. However, GHC 6.12.3 generates better code for 'fooName' than for 'barName'. In 'fooName', there is no pattern match against 'FooExtra'. In 'barName', there is a pattern match against 'BarExtra'. What makes these data types different?
IIRC, GHC 6.12.3 had some problems with type equalities. Did you try GHC 7.0.3? Cheers, =) -- Felipe.