EqualityConstraints extension?
At the moment, writing an equality constraint in a type requires at least one of the GADTs
or TypeFamilies
extensions. However, each of these has other effects. Could we have an EqualityConstraints
extension to permit equality constraints in types, but neither GADTs nor type families? Presumably this extension should imply MonoLocalBinds
.
The GADTs
extension could then become precisely the conjunction of GADTSyntax
, EqualityConstraints
and ExistentialQuantification
.
Trac metadata
Trac field | Value |
---|---|
Version | 7.11 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |