As-patterns for type signatures
The proposal: in any type signature, the presence of type variable
x@pat
matches the type specified by pat, and replaces any occurrences of the type variable x with pat. In particular, this might be comparable to defining
type x (free variables in pat) = pat
with scope solely to the right of the as-pattern. Alternately, it might be compared to an equality constraint (x ~ pat).
Trac metadata
Trac field | Value |
---|---|
Version | 6.11 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Parser) |
Test case | |
Differential revisions | |
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Blocking | |
CC | |
Operating system | |
Architecture |