11 Nov
2002
11 Nov
'02
2:50 p.m.
I'm trying out MPTC with functional dependencies for the first time in GHC. However, I'm not sure of the syntax. MPJ's ESOP 2000 paper gives the following example: class FiniteMap i e fm | fm -> (i,e) where emptyFM :: fm lookupFM :: i -> fm -> Maybe e extendFM :: i -> e -> fm -> fm but ghc (5.02.2 and 5.04.1) complain $ ghc-5.04.1 -fglasgow-exts -c -o FunDep.o FunDep.hs FunDep.hs:10: parse error on input `(' where the indicated line is that of the class declaration. What should the syntax be if it is not the above? Regards, Malcolm