stack overflow regression
I would like to teach GHC that <= is transitive. I tried a module that looks like this:
{-# LANGUAGE GADTs, Rank2Types, TypeOperators #-}
import GHC.TypeLits
trans :: (a <= b, b <= c) => ((a <= c) => d) -> d
trans = undefinedIn 7.8, this is a type error; in 7.10 the compiler thinks a long time before emitting a stack overflow exception.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.10.2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (Type checker) |
| Test case | |
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