Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : master
http://hackage.haskell.org/trac/ghc/changeset/940d1309e58382c889c2665227863fd790bdb21c >--------------------------------------------------------------- commit 940d1309e58382c889c2665227863fd790bdb21c Author: Simon Peyton Jones <[email protected]> Date: Wed Jun 22 17:37:47 2011 +0100 Add equality superclasses Hurrah. At last we can write class (F a ~ b) => C a b where { ... } This fruit of the fact that equalities are now values, and all evidence is handled uniformly. The main tricky point is that when translating to Core an evidence variable 'v' is represented either as either Var v or Coercion (CoVar v) depending on whether or not v is an equality. This leads to a few annoying calls to 'varToCoreExpr'. compiler/basicTypes/MkId.lhs | 4 +- compiler/deSugar/DsExpr.lhs | 18 +++++++- compiler/iface/BuildTyCl.lhs | 50 ++++++++++------------ compiler/typecheck/TcInstDcls.lhs | 85 +++++++++++++++++------------------- compiler/typecheck/TcMType.lhs | 9 +---- compiler/types/Class.lhs | 21 ++++------ 6 files changed, 92 insertions(+), 95 deletions(-) Diff suppressed because of size. To see it, use: git show 940d1309e58382c889c2665227863fd790bdb21c _______________________________________________ Cvs-ghc mailing list [email protected] http://www.haskell.org/mailman/listinfo/cvs-ghc
