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.List
28import Data.Maybe
29import Data.Function
30import qualified Data.Map as M
32import Language.PureScript.Values
33import Language.PureScript.Types
34import Language.PureScript.Names
35import Language.PureScript.Kinds
36import Language.PureScript.Declarations
38import Control.Monad (forM_)
39import Control.Monad.State
40import Control.Monad.Error
42typeCheckAll :: [Declaration] -> Check ()
43typeCheckAll [] = return ()
44typeCheckAll (DataDeclaration name args dctors : rest) = do
45 rethrow (("Error in type constructor " ++ show name ++ ":\n") ++) $ do
46 env <- getEnv
47 modulePath <- checkModulePath `fmap` get
48 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
49 ctorKind <- kindsOf (Just name) args (mapMaybe snd dctors)
50 putEnv $ env { types = M.insert (modulePath, name) (ctorKind, Data) (types env) }
51 forM_ dctors $ \(dctor, maybeTy) ->
52 rethrow (("Error in data constructor " ++ show name ++ ":\n") ++) $ do
53 env' <- getEnv
54 guardWith (show dctor ++ " is already defined") $ not $ M.member (modulePath, dctor) (dataConstructors env')
55 let retTy = foldl TypeApp (TypeConstructor (Qualified modulePath name)) (map TypeVar args)
56 let dctorTy = maybe retTy (\ty -> Function [ty] retTy) maybeTy
57 let polyType = mkForAll args dctorTy
58 putEnv $ env' { dataConstructors = M.insert (modulePath, dctor) polyType (dataConstructors env') }
59 typeCheckAll rest
60typeCheckAll (TypeSynonymDeclaration name args ty : rest) = do
61 rethrow (("Error in type synonym " ++ show name ++ ":\n") ++) $ do
62 env <- getEnv
63 modulePath <- checkModulePath `fmap` get
64 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
65 kind <- kindsOf (Just name) args [ty]
66 putEnv $ env { types = M.insert (modulePath, name) (kind, TypeSynonym) (types env)
67 , typeSynonyms = M.insert (modulePath, name) (args, ty) (typeSynonyms env) }
68 typeCheckAll rest
69typeCheckAll (TypeDeclaration name ty : ValueDeclaration name' val : rest) | name == name' =
70 typeCheckAll (ValueDeclaration name (TypedValue val ty) : rest)
71typeCheckAll (TypeDeclaration name _ : _) = throwError $ "Orphan type declaration for " ++ show name
72typeCheckAll (ValueDeclaration name val : rest) = do
73 rethrow (("Error in declaration " ++ show name ++ ":\n") ++) $ do
74 env <- getEnv
75 modulePath <- checkModulePath `fmap` get
76 case M.lookup (modulePath, name) (names env) of
77 Just ty -> throwError $ show name ++ " is already defined"
78 Nothing -> do
79 ty <- typeOf (Just name) val
80 putEnv (env { names = M.insert (modulePath, name) (ty, Value) (names env) })
81 typeCheckAll rest
82typeCheckAll (ExternDataDeclaration name kind : rest) = do
83 env <- getEnv
84 modulePath <- checkModulePath `fmap` get
85 guardWith (show name ++ " is already defined") $ not $ M.member (modulePath, name) (types env)
86 putEnv $ env { types = M.insert (modulePath, name) (kind, TypeSynonym) (types env) }
87 typeCheckAll rest
88typeCheckAll (ExternMemberDeclaration member name ty : rest) = do
89 rethrow (("Error in foreign import member declaration " ++ show name ++ ":\n") ++) $ do
90 env <- getEnv
91 modulePath <- checkModulePath `fmap` get
92 kind <- kindOf ty
93 guardWith "Expected kind *" $ kind == Star
94 case M.lookup (modulePath, name) (names env) of
95 Just _ -> throwError $ show name ++ " is already defined"
96 Nothing -> case ty of
97 _ | isSingleArgumentFunction ty -> do
98 putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env)
99 , members = M.insert (modulePath, name) member (members env) })
100 | otherwise -> throwError "Foreign member declarations must have function types, with an single argument."
101 typeCheckAll rest
102 where
103 isSingleArgumentFunction (Function [_] _) = True
104 isSingleArgumentFunction (ForAll _ ty) = isSingleArgumentFunction ty
105 isSingleArgumentFunction _ = False
106typeCheckAll (ExternDeclaration name ty : rest) = do
107 rethrow (("Error in foreign import declaration " ++ show name ++ ":\n") ++) $ do
108 env <- getEnv
109 modulePath <- checkModulePath `fmap` get
110 kind <- kindOf ty
111 guardWith "Expected kind *" $ kind == Star
112 case M.lookup (modulePath, name) (names env) of
113 Just _ -> throwError $ show name ++ " is already defined"
114 Nothing -> putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env) })
115 typeCheckAll rest
116typeCheckAll (FixityDeclaration _ name : rest) = do
117 typeCheckAll rest
118 env <- getEnv
119 modulePath <- checkModulePath `fmap` get
120 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (modulePath, Op name) $ names env
121typeCheckAll (ModuleDeclaration name decls : rest) = do
122 withModule name $ typeCheckAll decls
123 typeCheckAll rest
124typeCheckAll (ImportDeclaration modulePath idents : rest) = do
125 env <- getEnv
126 currentModule <- checkModulePath `fmap` get
127 rethrow errorMessage $ do
128 guardWith ("Module " ++ show modulePath ++ " does not exist") $ moduleExists env
129 case idents of
130 Nothing -> bindIdents (map snd $ filterModule env) currentModule env
131 Just idents -> bindIdents idents currentModule env
132 typeCheckAll rest
133 where errorMessage = (("Error in import declaration " ++ show modulePath ++ ":\n") ++)
134 filterModule = filter ((== modulePath) . fst) . M.keys . names
135 moduleExists env = not $ null $ filterModule env
136 bindIdents idents currentModule env =
137 forM_ idents $ \ident -> do
138 guardWith (show currentModule ++ "." ++ show ident ++ " is already defined") $ (currentModule, ident) `M.notMember` names env
139 case (modulePath, ident) `M.lookup` names env of
140 Just (pt, _) -> modifyEnv (\e -> e { names = M.insert (currentModule, ident) (pt, Alias modulePath ident) (names e) })
141 Nothing -> throwError (show modulePath ++ "." ++ show ident ++ " is undefined")