Poor warning for conflicting functional dependencies
E:\Neil\thesis>ghci obj\haskell2\Proof_default.hs
GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help
Loading package base ... linking ... done.
[1 of 1] Compiling Proof_default ( obj/haskell2/Proof_default.hs, interpreted
)
obj/haskell2/Proof_default.hs:177:0:
Functional dependencies conflict between instance declarations:
instance [incoherent] SubstRep
(Prop (Sat VarName)) ([VarName], [Expr]) (Prop (Sa
t Expr))
-- Defined at obj/haskell2/Proof_default.hs:177:0-75
instance [incoherent] SubstRep
(Prop (Sat Int)) ([Int], [Expr]) (Prop (Sat Expr))
-- Defined at obj/haskell2/Proof_default.hs:180:0-67
instance [incoherent] SubstRep
(Prop (Sat Int)) ([Int], [Expr]) (Prop (Sat Expr))
-- Defined at obj/haskell2/Proof_default.hs:180:0-67
Failed, modules loaded: none.
It has listed three items that conflict, but two of the items are actually the same. I would expect the error message to nub
the list of instances first. Sample file attached. This bug may have been fixed in HEAD, with the recent warnings patch, but I cannot check (not enough disk space!).
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | Unknown |
Architecture | Unknown |