module Language.PureScript.Pretty.Kinds (
prettyPrintKind
) where
import Data.Maybe (fromMaybe)
import Control.Arrow (ArrowPlus(..))
import Control.PatternArrows
import Language.PureScript.Kinds
import Language.PureScript.Pretty.Common
typeLiterals :: Pattern () Kind String
typeLiterals = mkPattern match
where
match Star = Just "*"
match Bang = Just "!"
match (KUnknown u) = Just $ 'u' : show u
match _ = Nothing
matchRow :: Pattern () Kind ((), Kind)
matchRow = mkPattern match
where
match (Row k) = Just ((), k)
match _ = Nothing
funKind :: Pattern () Kind (Kind, Kind)
funKind = mkPattern match
where
match (FunKind arg ret) = Just (arg, ret)
match _ = Nothing
prettyPrintKind :: Kind -> String
prettyPrintKind = fromMaybe (error "Incomplete pattern") . pattern matchKind ()
where
matchKind :: Pattern () Kind String
matchKind = buildPrettyPrinter operators (typeLiterals <+> fmap parens matchKind)
operators :: OperatorTable () Kind String
operators =
OperatorTable [ [ Wrap matchRow $ \_ k -> "# " ++ k]
, [ AssocR funKind $ \arg ret -> arg ++ " -> " ++ ret ] ]