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.Data
28import Data.Generics (mkT, everywhere)
29import Data.Maybe
30import qualified Data.Map as M
31import Control.Monad.State
32import Control.Monad.Error
33import Data.Either (rights, lefts)
35import Language.PureScript.Types
36import Language.PureScript.Names
37import Language.PureScript.Kinds
38import Language.PureScript.Declarations
39import Language.PureScript.Sugar.TypeClasses
41addDataType :: ModuleName -> ProperName -> [String] -> [(ProperName, Maybe Type)] -> Kind -> Check ()
42addDataType moduleName name args dctors ctorKind = do
43 env <- getEnv
44 putEnv $ env { types = M.insert (moduleName, name) (ctorKind, Data) (types env) }
45 forM_ dctors $ \(dctor, maybeTy) ->
46 rethrow (("Error in data constructor " ++ show name ++ ":\n") ++) $
47 addDataConstructor moduleName name args dctor maybeTy
49addDataConstructor :: ModuleName -> ProperName -> [String] -> ProperName -> Maybe Type -> Check ()
50addDataConstructor moduleName name args dctor maybeTy = do
51 env <- getEnv
52 dataConstructorIsNotDefined moduleName dctor
53 let retTy = foldl TypeApp (TypeConstructor (Qualified (Just moduleName) name)) (map TypeVar args)
54 let dctorTy = maybe retTy (\ty -> Function [ty] retTy) maybeTy
55 let polyType = mkForAll args dctorTy
56 putEnv $ env { dataConstructors = M.insert (moduleName, dctor) (qualifyAllUnqualifiedNames moduleName env polyType, DataConstructor) (dataConstructors env) }
58addTypeSynonym :: ModuleName -> ProperName -> [String] -> Type -> Kind -> Check ()
59addTypeSynonym moduleName name args ty kind = do
60 env <- getEnv
61 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env)
62 , typeSynonyms = M.insert (moduleName, name) (args, qualifyAllUnqualifiedNames moduleName env ty) (typeSynonyms env) }
64typeIsNotDefined :: ModuleName -> ProperName -> Check ()
65typeIsNotDefined moduleName name = do
66 env <- getEnv
67 guardWith (show name ++ " is already defined") $
68 not $ M.member (moduleName, name) (types env)
70dataConstructorIsNotDefined :: ModuleName -> ProperName -> Check ()
71dataConstructorIsNotDefined moduleName dctor = do
72 env <- getEnv
73 guardWith (show dctor ++ " is already defined") $
74 not $ M.member (moduleName, dctor) (dataConstructors env)
76valueIsNotDefined :: ModuleName -> Ident -> Check ()
77valueIsNotDefined moduleName name = do
78 env <- getEnv
79 case M.lookup (moduleName, name) (names env) of
80 Just _ -> throwError $ show name ++ " is already defined"
81 Nothing -> return ()
83addValue :: ModuleName -> Ident -> Type -> Check ()
84addValue moduleName name ty = do
85 env <- getEnv
86 putEnv (env { names = M.insert (moduleName, name) (qualifyAllUnqualifiedNames moduleName env ty, Value) (names env) })
88typeCheckAll :: ModuleName -> [Declaration] -> Check [Declaration]
89typeCheckAll _ [] = return []
90typeCheckAll moduleName (d@(DataDeclaration name args dctors) : rest) = do
91 rethrow (("Error in type constructor " ++ show name ++ ":\n") ++) $ do
92 typeIsNotDefined moduleName name
93 ctorKind <- kindsOf moduleName name args (mapMaybe snd dctors)
94 addDataType moduleName name args dctors ctorKind
95 ds <- typeCheckAll moduleName rest
96 return $ d : ds
97typeCheckAll moduleName (d@(DataBindingGroupDeclaration tys) : rest) = do
98 rethrow (("Error in data binding group " ++ show (map (\(name, _, _) -> name) tys) ++ ":\n") ++) $ do
99 forM_ tys $ \(name, _, _) ->
100 typeIsNotDefined moduleName name
101 ks <- kindsOfAll moduleName (map (\(name, args, dctors) -> (name, args, mapMaybe snd dctors)) tys)
102 forM_ (zip tys ks) $ \((name, args, dctors), ctorKind) ->
103 addDataType moduleName name args dctors ctorKind
104 ds <- typeCheckAll moduleName rest
105 return $ d : ds
106typeCheckAll moduleName (d@(TypeSynonymDeclaration name args ty) : rest) = do
107 rethrow (("Error in type synonym " ++ show name ++ ":\n") ++) $ do
108 typeIsNotDefined moduleName name
109 kind <- kindsOf moduleName name args [ty]
110 addTypeSynonym moduleName name args ty kind
111 ds <- typeCheckAll moduleName rest
112 return $ d : ds
113typeCheckAll _ (TypeDeclaration _ _ : _) = error "Type declarations should have been removed"
114typeCheckAll moduleName (ValueDeclaration name [] Nothing val : rest) = do
115 d <- rethrow (("Error in declaration " ++ show name ++ ":\n") ++) $ do
116 valueIsNotDefined moduleName name
117 [(_, (val', ty))] <- typesOf moduleName [(name, val)]
118 addValue moduleName name ty
119 return $ ValueDeclaration name [] Nothing val'
120 ds <- typeCheckAll moduleName rest
121 return $ d : ds
122typeCheckAll _ (ValueDeclaration _ _ _ _ : _) = error "Binders were not desugared"
123typeCheckAll moduleName (BindingGroupDeclaration vals : rest) = do
124 d <- rethrow (("Error in binding group " ++ show (map fst vals) ++ ":\n") ++) $ do
125 forM_ (map fst vals) $ \name ->
126 valueIsNotDefined moduleName name
127 tys <- typesOf moduleName vals
128 vals' <- forM (zip (map fst vals) (map snd tys)) $ \(name, (val, ty)) -> do
129 addValue moduleName name ty
130 return (name, val)
131 return $ BindingGroupDeclaration vals'
132 ds <- typeCheckAll moduleName rest
133 return $ d : ds
134typeCheckAll moduleName (d@(ExternDataDeclaration name kind) : rest) = do
135 env <- getEnv
136 guardWith (show name ++ " is already defined") $ not $ M.member (moduleName, name) (types env)
137 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env) }
138 ds <- typeCheckAll moduleName rest
139 return $ d : ds
140typeCheckAll moduleName (d@(ExternDeclaration name _ ty) : rest) = do
141 rethrow (("Error in foreign import declaration " ++ show name ++ ":\n") ++) $ do
142 env <- getEnv
143 kind <- kindOf moduleName ty
144 guardWith "Expected kind *" $ kind == Star
145 case M.lookup (moduleName, name) (names env) of
146 Just _ -> throwError $ show name ++ " is already defined"
147 Nothing -> putEnv (env { names = M.insert (moduleName, name) (qualifyAllUnqualifiedNames moduleName env ty, Extern) (names env) })
148 ds <- typeCheckAll moduleName rest
149 return $ d : ds
150typeCheckAll moduleName (d@(FixityDeclaration _ name) : rest) = do
151 ds <- typeCheckAll moduleName rest
152 env <- getEnv
153 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (moduleName, Op name) $ names env
154 return $ d : ds
155typeCheckAll currentModule (d@(ImportDeclaration moduleName idents) : rest) = do
156 env <- getEnv
157 rethrow errorMessage $ do
158 guardWith ("Module " ++ show moduleName ++ " does not exist") $ moduleExists env
159 case idents of
160 Nothing -> do
161 shadowIdents (map snd $ filterModule (names env)) env
162 shadowTypes (map snd $ filterModule (types env)) env
163 Just idents' -> do
164 shadowIdents (lefts idents') env
165 shadowTypes (rights idents') env
166 ds <- typeCheckAll currentModule rest
167 return $ d : ds
168 where errorMessage = (("Error in import declaration " ++ show moduleName ++ ":\n") ++)
169 filterModule = filter ((== moduleName) . fst) . M.keys
170 moduleExists env = not (null (filterModule (names env))) || not (null (filterModule (types env)))
171 shadowIdents idents' env =
172 forM_ idents' $ \ident -> do
173 case (moduleName, ident) `M.lookup` names env of
174 Just (_, Alias _ _) -> return ()
175 Just (pt, _) -> do
176 guardWith (show currentModule ++ "." ++ show ident ++ " is already defined") $ (currentModule, ident) `M.notMember` names env
177 modifyEnv (\e -> e { names = M.insert (currentModule, ident) (pt, Alias moduleName ident) (names e) })
178 Nothing -> throwError (show moduleName ++ "." ++ show ident ++ " is undefined")
179 shadowTypes pns env =
180 forM_ pns $ \pn -> do
181 case (moduleName, pn) `M.lookup` types env of
182 Nothing -> throwError (show moduleName ++ "." ++ show pn ++ " is undefined")
183 Just (_, DataAlias _ _) -> return ()
184 Just (k, _) -> do
185 guardWith (show currentModule ++ "." ++ show pn ++ " is already defined") $ (currentModule, pn) `M.notMember` types env
186 modifyEnv (\e -> e { types = M.insert (currentModule, pn) (k, DataAlias moduleName pn) (types e) })
187 let keys = map (snd . fst) . filter (\(_, (fn, _)) -> fn `constructs` pn) . M.toList . dataConstructors $ env
188 forM_ keys $ \dctor -> do
189 case (moduleName, dctor) `M.lookup` dataConstructors env of
190 Just (_, Alias _ _) -> return ()
191 Just (ctorTy, _) -> do
192 guardWith (show currentModule ++ "." ++ show dctor ++ " is already defined") $ (currentModule, dctor) `M.notMember` dataConstructors env
193 modifyEnv (\e -> e { dataConstructors = M.insert (currentModule, dctor) (ctorTy, Alias moduleName (Ident (runProperName dctor))) (dataConstructors e) })
194 Nothing -> throwError (show moduleName ++ "." ++ show dctor ++ " is undefined")
195 constructs (TypeConstructor (Qualified (Just mn) pn')) pn
196 = mn == moduleName && pn' == pn
197 constructs (ForAll _ ty) pn = ty `constructs` pn
198 constructs (Function _ ty) pn = ty `constructs` pn
199 constructs (TypeApp ty _) pn = ty `constructs` pn
200 constructs fn _ = error $ "Invalid arguments to constructs: " ++ show fn
201typeCheckAll moduleName (d@(TypeClassDeclaration _ _ _) : rest) = do
202 ds <- typeCheckAll moduleName rest
203 return $ d : ds
204typeCheckAll moduleName (d@(TypeInstanceDeclaration deps className ty _) : rest) = do
205 dictName <- Check . lift $ mkDictionaryValueName moduleName className ty
206 ds <- withTypeClassDictionaries [(dictName, deps, className, ty)] $
207 typeCheckAll moduleName rest
208 return $ d : ds
210qualifyAllUnqualifiedNames :: (Data d) => ModuleName -> Environment -> d -> d
211qualifyAllUnqualifiedNames mn env = everywhere (mkT go)
212 where
213 go :: Qualified ProperName -> Qualified ProperName
214 go qual = let (mn', pn') = canonicalizeType mn env qual
215 in Qualified (Just mn') pn'