elm/compiler/Types/Hints.hs

module Types.Hints (hints) where

import Control.Arrow (first)
import Control.Monad (liftM)
import Data.Maybe (catMaybes)
import qualified Data.Map as Map
import Guid
import qualified Libraries as Libs
import Parse.Library (iParse)
import Parse.Types
import qualified Types.Substitutions as Subs
import Types.Types

hints :: GuidCounter [(String, Scheme)]
hints = liftM catMaybes (mapM toScheme values)
 where
  values :: [(String, String)]
  values = addPrefixes (Map.toList (Map.map Map.toList Libs.libraries))

  addPrefixes :: [(String,[(String, String)])] -> [(String, String)]
  addPrefixes = concatMap (\(m,vs) -> map (first (\n -> m ++ "." ++ n)) vs)

  toScheme :: (String, String) -> GuidCounter (Maybe (String, Scheme))
  toScheme (name, 't':'y':'p':'e':' ':_) = return Nothing
  toScheme (name, 'd':'a':'t':'a':' ':_) = return Nothing
  toScheme (name, tipeString) =
    let err = "compiler error parsing type of " ++ name ++ ":\n" ++ tipeString in
    case iParse (fmap toType typeExpr) err tipeString of
      Left err   -> error (show err)
      Right tipe -> do scheme <- Subs.generalize [] =<< Subs.superize name tipe
                       return (Just (name, scheme))