TH.reify can be ambiguous when giving a name that's in multiple namespaces

What should this program do?

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeOperators #-}
module Bug where

import Language.Haskell.TH

(***) :: Bool -> Bool -> Bool
(***) _ _ = True

type (***) a b = Bool

$(return [])

main :: IO ()
main = putStrLn $(reify (mkName "***") >>= stringE . show)

The issue is that reify (mkName "***") could conceivable look up the Info of two different things: the value-level (***) or the type-level (***). In this case, it happens to pick the value-level one:

$ /opt/ghc/8.2.1/bin/runghc Bug.hs
VarI Bug.*** (AppT (AppT ArrowT (ConT GHC.Types.Bool)) (AppT (AppT ArrowT (ConT GHC.Types.Bool)) (ConT GHC.Types.Bool))) Nothing

So if you want to look up the type-level (***)'s info in this way, you're hosed.

If the above scenario seems contrived, and you find yourself thinking "but RyanGlScott, why don't you just use '(***) and ''(***)?", keep in mind that there are times I need to look up //unqualified// names, and in those situations, mkName is all I have at my disposal for creating the Name to look up.

There has to be a better way to go about business here. Perhaps we should introduce another function

reifyAll :: Name -> [Info]

That finds all possible Infos in all the namespaces the argument Name can be found in?

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Template Haskell
Test case
Differential revisions
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Blocking
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changed weight to 5

added Tbug TemplateHaskell Trac import labels

closed

Upon further thought, my needs are already addressed with the lookupValueName and lookupTypeName functions, which allow me to search in particular namespaces.

I now realize that the Haddocks for reify even point this out - d'oh!

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedInvalid

added Pnormal label