reify never provides the declaration of variables
The information returned by reify when provided a variable Name is
VarI Name Type (Maybe Dec) Fixity
The Dec part, due to be nested in Maybe, is clearly optional. In fact, according to Language.Haskell.TH.Syntax:
-- Nothing for lambda-bound variables, and
-- for anything else TH can't figure out
-- E.g. [| let x = 1 in $(do { d <- reify 'x; .. }) |]
However, the typechecker (TcSplice module) always returns Nothing. So it's simply not implemented.
I suggest either implementing the feature or removing the Dec part of VarI. Either way, the type should be consistent with the features offered in TH.
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Template Haskell |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | Unknown |
Architecture | Unknown |