Template Haskell cannot represent type wildcards
There does not appear to be a way for Template Haskell code to generate partial type signature wildcards. The type quasiquote [t|_|] results in Wildcard not allowed, and use in an expression quasiquote like [|() :: _|] results in Exotic form of type not (yet) handled by Template Haskell _.
It would be useful if TH code could partially constrain the type of the expressions it was generating, without needing to determine the type completely.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.10.1-rc1 |
| Type | FeatureRequest |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Template Haskell |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |
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Relates to
- #98797.10.17
- #105488.0.15
Activity
added Tfeature request TemplateHaskell Trac import labels
assigned to @adamgundry
Trac metadata
Trac field Value Related → #9879 (closed) mentioned in issue #10548 (closed)
unassigned @adamgundry
Trac metadata
Trac field Value Related #9879 (closed) → #9879 (closed), #10548 (closed) Duplicate of #10548 (closed).
Trac metadata
Trac field Value Resolution Unresolved → ResolvedDuplicate mentioned in commit 49373ffe
added Pnormal label
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