src/Type/Fragment.hs · elk

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elk/src/Type/Fragment.hs

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1{-# OPTIONS_GHC -Wall #-}

2module Type.Fragment where

4import qualified Data.List as List

5import qualified Data.Map as Map

7import Reporting.Annotation as A

8import Type.Type

11data Fragment = Fragment

12 { typeEnv :: Map.Map String (A.Located Type)

13 , vars :: [Variable]

14 , typeConstraint :: TypeConstraint

15 }

18emptyFragment :: Fragment

19emptyFragment =

20 Fragment Map.empty [] CTrue

23joinFragment :: Fragment -> Fragment -> Fragment

24joinFragment f1 f2 =

25 Fragment

26 { typeEnv =

27 Map.union (typeEnv f1) (typeEnv f2)

29 , vars =

30 vars f1 ++ vars f2

32 , typeConstraint =

33 typeConstraint f1 /\ typeConstraint f2

34 }

37joinFragments :: [Fragment] -> Fragment

38joinFragments =

39 List.foldl' (flip joinFragment) emptyFragment

42toScheme :: Fragment -> Scheme Type Variable

43toScheme fragment =

44 Scheme [] (vars fragment) (typeConstraint fragment) (typeEnv fragment)