Generating unique names with template haskell

I need to use template haskell to generate a few instances where those instances each use a foreign function obtained from a particular FunPtr.

As far as I'm aware, the only clean way to do this requires top level declarations of the form: foreign import ccall "dynamic" makeFun1 :: FunPtr Foo -> Foo

If there was either:

• Another way to do this without requiring top level named declarations.
• The possibility to use these within a where clause (template haskell would suggest so given that it lets you use Dec within a where).

Then I'd be fine probably be fine without names.

I've tried using newName as it apparently generates fresh names but I cannot get it work for me.

I've put a copy of the test case here. I compile with stack build --ghc-options="-ddump-splices -ddump-to-file" and the error is:

th-name-issue/app/Main.hs:7:12: error:
    Multiple declarations of ‘makeFun’
    Declared at: app/Main.hs:7:12
                 app/Main.hs:7:12

Then I run gvim .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/th-name-issue-exe/th-name-issue-exe-tmp/app/Main.dump-splices

And can see:

app/Main.hs:7:12-25: Splicing declarations
    template-haskell-2.11.0.0:Language.Haskell.TH.Quote.quoteDec
      importGen " stuff here "
  ======>
    foreign import ccall safe "dynamic" makeFun_a3pc
      :: GHC.Ptr.FunPtr (Foreign.C.String.CString -> IO ())
         -> Foreign.C.String.CString -> IO ()
    foreign import ccall safe "dynamic" makeFun_a3pd
      :: GHC.Ptr.FunPtr (Foreign.C.String.CString -> IO ())
         -> Foreign.C.String.CString -> IO ()

Which suggests that I did manage to get unique names after all, so I don't know why it didn't compile??

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Template Haskell
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