module Types.Unify (unify) where

import Control.Monad (liftM)
import qualified Data.Map as Map

import Ast
import Guid
import qualified Types.Constrain as Constrain
import qualified Types.Solver as Solver
import qualified Types.Alias as Alias

import qualified Types.Substitutions as Subst
import System.IO.Unsafe
import Control.Arrow (second)

unify hints modul@(Module _ _ _ stmts) = run $ do
  result <- Constrain.constrain hints modul
  case result of
    Left err -> return (Left err)
    Right (schemes, constraints) ->
        do subs <- Solver.solver (Alias.get stmts) Map.empty constraints
           let ss = either (const []) Map.toList subs
           unsafePerformIO (mapM print . map (second (Subst.subst ss)) $ concatMap Map.toList schemes) `seq` return subs