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
29import Control.Monad.State
30import Control.Monad.Error
31import Data.Either (rights, lefts)
33import Language.PureScript.Types
34import Language.PureScript.Names
35import Language.PureScript.Values
36import Language.PureScript.Kinds
37import Language.PureScript.Declarations
38import Language.PureScript.Sugar.TypeClasses
40addDataType :: ModuleName -> ProperName -> [String] -> [(ProperName, Maybe Type)] -> Kind -> Check ()
41addDataType moduleName name args dctors ctorKind = do
42 env <- getEnv
43 putEnv $ env { types = M.insert (moduleName, name) (ctorKind, Data) (types env) }
44 forM_ dctors $ \(dctor, maybeTy) ->
45 rethrow (("Error in data constructor " ++ show name ++ ":\n") ++) $
46 addDataConstructor moduleName name args dctor maybeTy
48addDataConstructor :: ModuleName -> ProperName -> [String] -> ProperName -> Maybe Type -> Check ()
49addDataConstructor moduleName name args dctor maybeTy = do
50 env <- getEnv
51 dataConstructorIsNotDefined moduleName dctor
52 let retTy = foldl TypeApp (TypeConstructor (Qualified (Just moduleName) 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 (moduleName, dctor) (qualifyAllUnqualifiedNames moduleName env polyType, DataConstructor) (dataConstructors env) }
57addTypeSynonym :: ModuleName -> ProperName -> [String] -> Type -> Kind -> Check ()
58addTypeSynonym moduleName name args ty kind = do
59 env <- getEnv
60 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env)
61 , typeSynonyms = M.insert (moduleName, name) (args, qualifyAllUnqualifiedNames moduleName env ty) (typeSynonyms env) }
63typeIsNotDefined :: ModuleName -> ProperName -> Check ()
64typeIsNotDefined moduleName name = do
65 env <- getEnv
66 guardWith (show name ++ " is already defined") $
67 not $ M.member (moduleName, name) (types env)
69dataConstructorIsNotDefined :: ModuleName -> ProperName -> Check ()
70dataConstructorIsNotDefined moduleName dctor = do
71 env <- getEnv
72 guardWith (show dctor ++ " is already defined") $
73 not $ M.member (moduleName, dctor) (dataConstructors env)
75valueIsNotDefined :: ModuleName -> Ident -> Check ()
76valueIsNotDefined moduleName name = do
77 env <- getEnv
78 case M.lookup (moduleName, name) (names env) of
79 Just _ -> throwError $ show name ++ " is already defined"
80 Nothing -> return ()
82addValue :: ModuleName -> Ident -> Type -> Check ()
83addValue moduleName name ty = do
84 env <- getEnv
85 putEnv (env { names = M.insert (moduleName, name) (qualifyAllUnqualifiedNames moduleName env ty, Value) (names env) })
87addTypeClassDictionaries :: [TypeClassDictionaryInScope] -> Check ()
88addTypeClassDictionaries entries = do
89 modify $ \st -> st { checkEnv = (checkEnv st) { typeClassDictionaries = entries ++ (typeClassDictionaries . checkEnv $ st) } }
91typeCheckAll :: ModuleName -> [Declaration] -> Check [Declaration]
92typeCheckAll _ [] = return []
93typeCheckAll moduleName (d@(DataDeclaration name args dctors) : rest) = do
94 rethrow (("Error in type constructor " ++ show name ++ ":\n") ++) $ do
95 typeIsNotDefined moduleName name
96 ctorKind <- kindsOf moduleName name args (mapMaybe snd dctors)
97 addDataType moduleName name args dctors ctorKind
98 ds <- typeCheckAll moduleName rest
99 return $ d : ds
100typeCheckAll moduleName (d@(DataBindingGroupDeclaration tys) : rest) = do
101 rethrow (("Error in data binding group " ++ show (map (\(name, _, _) -> name) tys) ++ ":\n") ++) $ do
102 forM_ tys $ \(name, _, _) ->
103 typeIsNotDefined moduleName name
104 ks <- kindsOfAll moduleName (map (\(name, args, dctors) -> (name, args, mapMaybe snd dctors)) tys)
105 forM_ (zip tys ks) $ \((name, args, dctors), ctorKind) ->
106 addDataType moduleName name args dctors ctorKind
107 ds <- typeCheckAll moduleName rest
108 return $ d : ds
109typeCheckAll moduleName (d@(TypeSynonymDeclaration name args ty) : rest) = do
110 rethrow (("Error in type synonym " ++ show name ++ ":\n") ++) $ do
111 typeIsNotDefined moduleName name
112 kind <- kindsOf moduleName name args [ty]
113 addTypeSynonym moduleName name args ty kind
114 ds <- typeCheckAll moduleName rest
115 return $ d : ds
116typeCheckAll _ (TypeDeclaration _ _ : _) = error "Type declarations should have been removed"
117typeCheckAll moduleName (ValueDeclaration name [] Nothing val : rest) = do
118 d <- rethrow (("Error in declaration " ++ show name ++ ":\n") ++) $ do
119 valueIsNotDefined moduleName name
120 [(_, (val', ty))] <- typesOf moduleName [(name, val)]
121 addValue moduleName name ty
122 return $ ValueDeclaration name [] Nothing val'
123 ds <- typeCheckAll moduleName rest
124 return $ d : ds
125typeCheckAll _ (ValueDeclaration _ _ _ _ : _) = error "Binders were not desugared"
126typeCheckAll moduleName (BindingGroupDeclaration vals : rest) = do
127 d <- rethrow (("Error in binding group " ++ show (map fst vals) ++ ":\n") ++) $ do
128 forM_ (map fst vals) $ \name ->
129 valueIsNotDefined moduleName name
130 tys <- typesOf moduleName vals
131 vals' <- forM (zip (map fst vals) (map snd tys)) $ \(name, (val, ty)) -> do
132 addValue moduleName name ty
133 return (name, val)
134 return $ BindingGroupDeclaration vals'
135 ds <- typeCheckAll moduleName rest
136 return $ d : ds
137typeCheckAll moduleName (d@(ExternDataDeclaration name kind) : rest) = do
138 env <- getEnv
139 guardWith (show name ++ " is already defined") $ not $ M.member (moduleName, name) (types env)
140 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env) }
141 ds <- typeCheckAll moduleName rest
142 return $ d : ds
143typeCheckAll moduleName (d@(ExternDeclaration importTy name _ ty) : rest) = do
144 rethrow (("Error in foreign import declaration " ++ show name ++ ":\n") ++) $ do
145 env <- getEnv
146 kind <- kindOf moduleName ty
147 guardWith "Expected kind *" $ kind == Star
148 case M.lookup (moduleName, name) (names env) of
149 Just _ -> throwError $ show name ++ " is already defined"
150 Nothing -> putEnv (env { names = M.insert (moduleName, name) (qualifyAllUnqualifiedNames moduleName env ty, Extern importTy) (names env) })
151 ds <- typeCheckAll moduleName rest
152 return $ d : ds
153typeCheckAll moduleName (d@(FixityDeclaration _ name) : rest) = do
154 ds <- typeCheckAll moduleName rest
155 env <- getEnv
156 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (moduleName, Op name) $ names env
157 return $ d : ds
158typeCheckAll currentModule (d@(ImportDeclaration moduleName idents) : rest) = do
159 env <- getEnv
160 rethrow errorMessage $ do
161 guardWith ("Module " ++ show moduleName ++ " does not exist") $ moduleExists env
162 case idents of
163 Nothing -> do
164 shadowIdents (map snd $ filterModule (names env)) env
165 shadowTypes (map snd $ filterModule (types env)) env
166 Just idents' -> do
167 shadowIdents (lefts idents') env
168 shadowTypes (rights idents') env
169 shadowTypeClassInstances env
170 ds <- typeCheckAll currentModule rest
171 return $ d : ds
172 where
173 errorMessage = (("Error in import declaration " ++ show moduleName ++ ":\n") ++)
174 filterModule = filter ((== moduleName) . fst) . M.keys
175 moduleExists env = not (null (filterModule (names env))) || not (null (filterModule (types env)))
176 shadowIdents idents' env =
177 forM_ idents' $ \ident -> do
178 case (moduleName, ident) `M.lookup` names env of
179 Just (_, Alias _ _) -> return ()
180 Just (pt, _) -> do
181 guardWith (show currentModule ++ "." ++ show ident ++ " is already defined") $ (currentModule, ident) `M.notMember` names env
182 modifyEnv (\e -> e { names = M.insert (currentModule, ident) (pt, Alias moduleName ident) (names e) })
183 Nothing -> throwError (show moduleName ++ "." ++ show ident ++ " is undefined")
184 shadowTypes pns env =
185 forM_ pns $ \pn -> do
186 case (moduleName, pn) `M.lookup` types env of
187 Nothing -> throwError (show moduleName ++ "." ++ show pn ++ " is undefined")
188 Just (_, DataAlias _ _) -> return ()
189 Just (k, _) -> do
190 guardWith (show currentModule ++ "." ++ show pn ++ " is already defined") $ (currentModule, pn) `M.notMember` types env
191 modifyEnv (\e -> e { types = M.insert (currentModule, pn) (k, DataAlias moduleName pn) (types e) })
192 let keys = map (snd . fst) . filter (\(_, (fn, _)) -> fn `constructs` pn) . M.toList . dataConstructors $ env
193 forM_ keys $ \dctor -> do
194 case (moduleName, dctor) `M.lookup` dataConstructors env of
195 Just (_, Alias _ _) -> return ()
196 Just (ctorTy, _) -> do
197 guardWith (show currentModule ++ "." ++ show dctor ++ " is already defined") $ (currentModule, dctor) `M.notMember` dataConstructors env
198 modifyEnv (\e -> e { dataConstructors = M.insert (currentModule, dctor) (ctorTy, Alias moduleName (Ident (runProperName dctor))) (dataConstructors e) })
199 Nothing -> throwError (show moduleName ++ "." ++ show dctor ++ " is undefined")
200 shadowTypeClassInstances env = do
201 let instances = filter (\tcd ->
202 let Qualified (Just mn) _ = tcdName tcd in
203 moduleName == mn && tcdType tcd == TCDRegular
204 ) (typeClassDictionaries env)
205 forM_ instances $ \tcd -> do
206 let (Qualified _ ident) = tcdName tcd
207 addTypeClassDictionaries [tcd { tcdName = (Qualified (Just currentModule) ident), tcdType = TCDAlias (tcdName tcd) }]
208 constructs (TypeConstructor (Qualified (Just mn) pn')) pn
209 = mn == moduleName && pn' == pn
210 constructs (ForAll _ ty) pn = ty `constructs` pn
211 constructs (Function _ ty) pn = ty `constructs` pn
212 constructs (TypeApp ty _) pn = ty `constructs` pn
213 constructs fn _ = error $ "Invalid arguments to constructs: " ++ show fn
214typeCheckAll moduleName (d@(TypeClassDeclaration _ _ _) : rest) = do
215 env <- getEnv
216 ds <- typeCheckAll moduleName rest
217 return $ qualifyAllUnqualifiedNames moduleName env d : ds
218typeCheckAll moduleName (d@(TypeInstanceDeclaration deps className ty _) : rest) = do
219 env <- getEnv
220 dictName <- Check . lift $ mkDictionaryValueName moduleName className ty
221 addTypeClassDictionaries (qualifyAllUnqualifiedNames moduleName env
222 [TypeClassDictionaryInScope (Qualified (Just moduleName) dictName) className ty (Just deps) TCDRegular])
223 ds <- typeCheckAll moduleName rest
224 return $ qualifyAllUnqualifiedNames moduleName env d : ds