subhask-0.1.0.0: src/SubHask/TemplateHaskell/Common.hs

module SubHask.TemplateHaskell.Common
    where

import Prelude
import Data.List (init,last,nub,intersperse)
import Language.Haskell.TH.Syntax
import Control.Monad

bndr2type :: TyVarBndr -> Type
bndr2type (PlainTV n) = VarT n
bndr2type (KindedTV n _) = VarT n

isStar :: TyVarBndr -> Bool
isStar (PlainTV _) = True
isStar (KindedTV _ StarT) = True
isStar _ = False

apply2varlist :: Type -> [TyVarBndr] -> Type
apply2varlist contype xs = go $ reverse xs
    where
        go (x:[]) = AppT contype (mkVar x)
        go (x:xs) = AppT (go xs) (mkVar x)

        mkVar (PlainTV n) = VarT n
        mkVar (KindedTV n _) = VarT n