[Template-haskell] How to extract name and type of exported functions in modules

[Oscar Finnsson]

Hi,

I'm trying to extract the names and types of exported functions in a module.

At the moment I've managed to get a list of all functions in a module
but I can't seem to figure out how to get their types.

Lets say I got the module

    module Foo where

    foo1 :: String -> String
    foo1 value = value

    foo2 = "hej"

and then in anothor module...

    module Bar where

    bar = $(getAllFunctions "<some-path>/Foo.hs")

At the moment I got getAllFunctions returning ["foo1","foo2"], but I
would really like to get it to return [("foo1",AppT (ConT "String")
(ConT "String")), ("foo2",ConT "String")]

Using "parseModuleWithMode" from Language.Haskell.Exts I can get hold
of the names and the type signature of foo1 (since it's specified in
the source code) but I cannot get hold of the type signature of foo2
(since it's not specified in the source code).

Is there another way to get the names/signatures of exported functions
from a module other than using parseModuleWithMode so the developer
writing the Foo-module isn't forced to explicitly supply type
signatures of the exported functions?

If I try "reify" to get information about the functions I get the error message:
"foo1 is not in scope at a reify"

This seems to be a known bug about reify (reported here
http://hackage.haskell.org/trac/ghc/ticket/2339). My problem is that I
cannot use the workaround since I don't know the name of the
functions.

Another disadvantage with this approach is that "getAllFunctions" must
have access to the source code of the module and that I must supply
the path the the module. If possible I would like to have code such as

    bar = $(getAllFunctions "Foo")

instead of "<come-path>/Foo.hs".

Regards,
Oscar Finnsson