git.iko.soy/rowtype-yoga/purescript-native
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rowtype-yoga/purescript-native/src/Language/PureScript/TypeChecker.hs
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1-----------------------------------------------------------------------------
2--
3-- Module : Language.PureScript.TypeChecker
4-- Copyright : (c) Phil Freeman 2013
5-- License : MIT
6--
7-- Maintainer : Phil Freeman <paf31@cantab.net>
8-- Stability : experimental
9-- Portability :
10--
11-- |
12--
13-----------------------------------------------------------------------------
15{-# LANGUAGE FlexibleInstances #-}
17module Language.PureScript.TypeChecker (
18 module T,
19 typeCheckAll
20) where
22import Language.PureScript.TypeChecker.Monad as T
23import Language.PureScript.TypeChecker.Kinds as T
24import Language.PureScript.TypeChecker.Types as T
25import Language.PureScript.TypeChecker.Synonyms as T
27import Data.Maybe
28import qualified Data.Map as M
30import Language.PureScript.Values
31import Language.PureScript.Types
32import Language.PureScript.Names
33import Language.PureScript.Kinds
34import Language.PureScript.Declarations
36import Control.Monad.State
37import Control.Monad.Error
39typeCheckAll :: [Declaration] -> Check ()
40typeCheckAll [] = return ()
41typeCheckAll (DataDeclaration name args dctors : rest) = do
42 rethrow (("Error in type constructor " ++ show name ++ ":\n") ++) $ do
43 env <- getEnv
44 modulePath <- checkModulePath `fmap` get
45 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
46 ctorKind <- kindsOf (Just name) args (mapMaybe snd dctors)
47 putEnv $ env { types = M.insert (modulePath, name) (ctorKind, Data) (types env) }
48 forM_ dctors $ \(dctor, maybeTy) ->
49 rethrow (("Error in data constructor " ++ show name ++ ":\n") ++) $ do
50 env' <- getEnv
51 guardWith (show dctor ++ " is already defined") $ not $ M.member (modulePath, dctor) (dataConstructors env')
52 let retTy = foldl TypeApp (TypeConstructor (Qualified modulePath name)) (map TypeVar args)
53 let dctorTy = maybe retTy (\ty -> Function [ty] retTy) maybeTy
54 let polyType = mkForAll args dctorTy
55 putEnv $ env' { dataConstructors = M.insert (modulePath, dctor) polyType (dataConstructors env') }
56 typeCheckAll rest
57typeCheckAll (TypeSynonymDeclaration name args ty : rest) = do
58 rethrow (("Error in type synonym " ++ show name ++ ":\n") ++) $ do
59 env <- getEnv
60 modulePath <- checkModulePath `fmap` get
61 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
62 kind <- kindsOf (Just name) args [ty]
63 putEnv $ env { types = M.insert (modulePath, name) (kind, TypeSynonym) (types env)
64 , typeSynonyms = M.insert (modulePath, name) (args, ty) (typeSynonyms env) }
65 typeCheckAll rest
66typeCheckAll (TypeDeclaration name ty : ValueDeclaration name' [] Nothing val : rest) | name == name' =
67 typeCheckAll (ValueDeclaration name [] Nothing (TypedValue val ty) : rest)
68typeCheckAll (TypeDeclaration name _ : _) = throwError $ "Orphan type declaration for " ++ show name
69typeCheckAll (ValueDeclaration name [] Nothing val : rest) = do
70 rethrow (("Error in declaration " ++ show name ++ ":\n") ++) $ do
71 env <- getEnv
72 modulePath <- checkModulePath `fmap` get
73 case M.lookup (modulePath, name) (names env) of
74 Just _ -> throwError $ show name ++ " is already defined"
75 Nothing -> do
76 ty <- typeOf (Just name) val
77 putEnv (env { names = M.insert (modulePath, name) (ty, Value) (names env) })
78 typeCheckAll rest
79typeCheckAll (ValueDeclaration _ _ _ _ : _) = error "Binders were not desugared"
80typeCheckAll (ExternDataDeclaration name kind : rest) = do
81 env <- getEnv
82 modulePath <- checkModulePath `fmap` get
83 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
84 putEnv $ env { types = M.insert (modulePath, name) (kind, TypeSynonym) (types env) }
85 typeCheckAll rest
86typeCheckAll (ExternMemberDeclaration member name ty : rest) = do
87 rethrow (("Error in foreign import member declaration " ++ show name ++ ":\n") ++) $ do
88 env <- getEnv
89 modulePath <- checkModulePath `fmap` get
90 kind <- kindOf ty
91 guardWith "Expected kind *" $ kind == Star
92 case M.lookup (modulePath, name) (names env) of
93 Just _ -> throwError $ show name ++ " is already defined"
94 Nothing -> case ty of
95 _ | isSingleArgumentFunction ty -> do
96 putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env)
97 , members = M.insert (modulePath, name) member (members env) })
98 | otherwise -> throwError "Foreign member declarations must have function types, with an single argument."
99 typeCheckAll rest
100 where
101 isSingleArgumentFunction (Function [_] _) = True
102 isSingleArgumentFunction (ForAll _ t) = isSingleArgumentFunction t
103 isSingleArgumentFunction _ = False
104typeCheckAll (ExternDeclaration name ty : rest) = do
105 rethrow (("Error in foreign import declaration " ++ show name ++ ":\n") ++) $ do
106 env <- getEnv
107 modulePath <- checkModulePath `fmap` get
108 kind <- kindOf ty
109 guardWith "Expected kind *" $ kind == Star
110 case M.lookup (modulePath, name) (names env) of
111 Just _ -> throwError $ show name ++ " is already defined"
112 Nothing -> putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env) })
113 typeCheckAll rest
114typeCheckAll (FixityDeclaration _ name : rest) = do
115 typeCheckAll rest
116 env <- getEnv
117 modulePath <- checkModulePath `fmap` get
118 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (modulePath, Op name) $ names env
119typeCheckAll (ModuleDeclaration name decls : rest) = do
120 withModule name $ typeCheckAll decls
121 typeCheckAll rest
122typeCheckAll (ImportDeclaration modulePath idents : rest) = do
123 env <- getEnv
124 currentModule <- checkModulePath `fmap` get
125 rethrow errorMessage $ do
126 guardWith ("Module " ++ show modulePath ++ " does not exist") $ moduleExists env
127 case idents of
128 Nothing -> bindIdents (map snd $ filterModule env) currentModule env
129 Just idents' -> bindIdents idents' currentModule env
130 typeCheckAll rest
131 where errorMessage = (("Error in import declaration " ++ show modulePath ++ ":\n") ++)
132 filterModule = filter ((== modulePath) . fst) . M.keys . names
133 moduleExists env = not $ null $ filterModule env
134 bindIdents idents' currentModule env =
135 forM_ idents' $ \ident -> do
136 guardWith (show currentModule ++ "." ++ show ident ++ " is already defined") $ (currentModule, ident) `M.notMember` names env
137 case (modulePath, ident) `M.lookup` names env of
138 Just (pt, _) -> modifyEnv (\e -> e { names = M.insert (currentModule, ident) (pt, Alias modulePath ident) (names e) })
139 Nothing -> throwError (show modulePath ++ "." ++ show ident ++ " is undefined")