patch applied (ghc): Fix Trac #3219: type of a record update
Simon Peyton Jones
simonpj at microsoft.com
Wed May 13 11:46:32 EDT 2009
Wed May 13 08:09:22 PDT 2009 simonpj at microsoft.com
* Fix Trac #3219: type of a record update
Record updates are amazingly hard to typecheck right. This is one place
where GHC's policy of typechecking the original source is much harder than
desugaring and typechecking that!
Anyway, the bug here is that to compute the 'fixed' type variables I was
only looking at one constructor rather than all the relevant_cons
Test is typecheck/should_compile/T3219, which GHC 6.10 barfs on (with Lint).
M ./compiler/typecheck/TcExpr.lhs -28 +41
View patch online:
More information about the Cvs-ghc