compiler/Type/Inference.hs · elk

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elk/compiler/Type/Inference.hs

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1module Type.Inference where

3import qualified Data.Map as Map

5import qualified Type.Type as T

6import qualified Type.Environment as Env

7import qualified Type.Constrain.Expression as TcExpr

8import qualified Type.Constrain.Declaration as TcDecl

9import qualified Type.Solve as Solve

11import SourceSyntax.Module

12import qualified SourceSyntax.Expression as Expr

13import SourceSyntax.PrettyPrint

14import Text.PrettyPrint

15import qualified Type.State as TS

16import Control.Monad.State

17import Control.Arrow (second)

18import Transform.SortDefinitions as Sort

20import System.IO.Unsafe -- Possible to switch over to the ST monad instead of

21 -- the IO monad. Not sure if that'd be worthwhile.

24infer :: MetadataModule t v -> Either [Doc] (Map.Map String T.Variable)

25infer modul = unsafePerformIO $ do

26 env <- Env.initialEnvironment (datatypes modul)

27 var <- T.flexibleVar

28 ctors <- forM (Map.keys (Env.constructor env)) $ \name ->

29 do (_, vars, tipe) <- Env.freshDataScheme env name

30 return (name, (vars, tipe))

32 let vars = concatMap (fst . snd) ctors

33 header = Map.map snd (Map.fromList ctors)

34 environ = T.CLet [ T.Scheme vars [] T.CTrue header ]

35 constraint <- environ `fmap` TcExpr.constrain env (program modul) (T.VarN var)

36 state <- execStateT (Solve.solve constraint) TS.initialState

37 let errors = TS.sErrors state

38 if null errors

39 then return $ Right (Map.difference (TS.sSavedEnv state) header)

40 else Left `fmap` sequence errors