TypeApplications + RankNTypes permits "impredicativity"
I was slightly surprised to discover that the combination of TypeApplications and RankNTypes allows impredicative instantiations, for example:
map @(forall a . a) :: ((forall a. a) -> b) -> [forall a. a] -> [b]Is this desirable, or should it require ImpredicativeTypes?
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.11 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | goldfire |
| Operating system | |
| Architecture |