Data.PolyTypeable.Utils

Usage:

 > polyTypeOf id
 a1 -> a1

 > freeTyVars (polyTypeOf id)
 ["a1"]

 > substTyVar ("a1",polyTypeOf(undefined::Int)) (polyTypeOf id)
 Int -> Int

 > polyTypeOf const
 a1 -> a2 -> a1

 > freeTyVars (polyTypeOf const) 
 ["a1","a2"]

 > substManyTyVars [("a1",polyTypeOf(undefined::Int)),("a2",polyTypeOf(undefined::Bool))] (polyTypeOf const)
 Int -> Bool -> Int

Documentation

freeTyVars :: TypeRep -> [String]

collect free type variables (e.g. a1, a2, ...) without duplicates

substTyVar :: (String, TypeRep) -> TypeRep -> TypeRep

substitue a type variable

substTyVars :: [(String, TypeRep)] -> TypeRep -> TypeRep

substitue many type variables