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.Types
31import Language.PureScript.Names
32import Language.PureScript.Kinds
33import Language.PureScript.Declarations
35import Control.Monad.State
36import Control.Monad.Error
38typeCheckAll :: ModuleName -> [Declaration] -> Check ()
39typeCheckAll _ [] = return ()
40typeCheckAll moduleName (DataDeclaration name args dctors : rest) = do
41 rethrow (("Error in type constructor " ++ show name ++ ":\n") ++) $ do
42 env <- getEnv
43 guardWith (show name ++ " is already defined") $ not $ M.member (moduleName, name) (types env)
44 ctorKind <- kindsOf moduleName (Just name) args (mapMaybe snd dctors)
45 putEnv $ env { types = M.insert (moduleName, name) (ctorKind, Data) (types env) }
46 forM_ dctors $ \(dctor, maybeTy) ->
47 rethrow (("Error in data constructor " ++ show name ++ ":\n") ++) $ do
48 env' <- getEnv
49 guardWith (show dctor ++ " is already defined") $ not $ M.member (moduleName, dctor) (dataConstructors env')
50 let retTy = foldl TypeApp (TypeConstructor (Qualified (Just moduleName) name)) (map TypeVar args)
51 let dctorTy = maybe retTy (\ty -> Function [ty] retTy) maybeTy
52 let polyType = mkForAll args dctorTy
53 putEnv $ env' { dataConstructors = M.insert (moduleName, dctor) polyType (dataConstructors env') }
54 typeCheckAll moduleName rest
55typeCheckAll moduleName (TypeSynonymDeclaration name args ty : rest) = do
56 rethrow (("Error in type synonym " ++ show name ++ ":\n") ++) $ do
57 env <- getEnv
58 guardWith (show name ++ " is already defined") $ not $ M.member (moduleName, name) (types env)
59 kind <- kindsOf moduleName (Just name) args [ty]
60 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env)
61 , typeSynonyms = M.insert (moduleName, name) (args, ty) (typeSynonyms env) }
62 typeCheckAll moduleName rest
63typeCheckAll _ (TypeDeclaration _ _ : _) = error "Type declarations should have been removed"
64typeCheckAll moduleName (ValueDeclaration name [] Nothing val : rest) = do
65 rethrow (("Error in declaration " ++ show name ++ ":\n") ++) $ do
66 env <- getEnv
67 case M.lookup (moduleName, name) (names env) of
68 Just _ -> throwError $ show name ++ " is already defined"
69 Nothing -> do
70 [ty] <- typesOf moduleName [(name, val)]
71 putEnv (env { names = M.insert (moduleName, name) (ty, Value) (names env) })
72 typeCheckAll moduleName rest
73typeCheckAll _ (ValueDeclaration _ _ _ _ : _) = error "Binders were not desugared"
74typeCheckAll moduleName (BindingGroupDeclaration vals : rest) = do
75 rethrow (("Error in binding group " ++ show (map fst vals) ++ ":\n") ++) $ do
76 forM_ (map fst vals) $ \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 ()
81 tys <- typesOf moduleName vals
82 forM (zip (map fst vals) tys) $ \(name, ty) ->
83 modifyEnv $ \env -> env { names = M.insert (moduleName, name) (ty, Value) (names env) }
84 typeCheckAll moduleName rest
85typeCheckAll moduleName (ExternDataDeclaration name kind : rest) = do
86 env <- getEnv
87 guardWith (show name ++ " is already defined") $ not $ M.member (moduleName, name) (types env)
88 putEnv $ env { types = M.insert (moduleName, name) (kind, TypeSynonym) (types env) }
89 typeCheckAll moduleName rest
90typeCheckAll moduleName (ExternMemberDeclaration member name ty : rest) = do
91 rethrow (("Error in foreign import member declaration " ++ show name ++ ":\n") ++) $ do
92 env <- getEnv
93 kind <- kindOf moduleName ty
94 guardWith "Expected kind *" $ kind == Star
95 case M.lookup (moduleName, name) (names env) of
96 Just _ -> throwError $ show name ++ " is already defined"
97 Nothing -> case ty of
98 _ | isSingleArgumentFunction ty -> do
99 putEnv (env { names = M.insert (moduleName, name) (ty, Extern) (names env)
100 , members = M.insert (moduleName, name) member (members env) })
101 | otherwise -> throwError "Foreign member declarations must have function types, with an single argument."
102 typeCheckAll moduleName rest
103 where
104 isSingleArgumentFunction (Function [_] _) = True
105 isSingleArgumentFunction (ForAll _ t) = isSingleArgumentFunction t
106 isSingleArgumentFunction _ = False
107typeCheckAll moduleName (ExternDeclaration name ty : rest) = do
108 rethrow (("Error in foreign import declaration " ++ show name ++ ":\n") ++) $ do
109 env <- getEnv
110 kind <- kindOf moduleName ty
111 guardWith "Expected kind *" $ kind == Star
112 case M.lookup (moduleName, name) (names env) of
113 Just _ -> throwError $ show name ++ " is already defined"
114 Nothing -> putEnv (env { names = M.insert (moduleName, name) (ty, Extern) (names env) })
115 typeCheckAll moduleName rest
116typeCheckAll moduleName (FixityDeclaration _ name : rest) = do
117 typeCheckAll moduleName rest
118 env <- getEnv
119 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (moduleName, Op name) $ names env
120typeCheckAll currentModule (ImportDeclaration moduleName idents : rest) = do
121 env <- getEnv
122 rethrow errorMessage $ do
123 guardWith ("Module " ++ show moduleName ++ " does not exist") $ moduleExists env
124 case idents of
125 Nothing -> bindIdents (map snd $ filterModule env) env
126 Just idents' -> bindIdents idents' env
127 typeCheckAll moduleName rest
128 where errorMessage = (("Error in import declaration " ++ show moduleName ++ ":\n") ++)
129 filterModule = filter ((== moduleName) . fst) . M.keys . names
130 moduleExists env = not $ null $ filterModule env
131 bindIdents idents' env =
132 forM_ idents' $ \ident -> do
133 guardWith (show currentModule ++ "." ++ show ident ++ " is already defined") $ (currentModule, ident) `M.notMember` names env
134 case (moduleName, ident) `M.lookup` names env of
135 Just (pt, _) -> modifyEnv (\e -> e { names = M.insert (currentModule, ident) (pt, Alias moduleName ident) (names e) })
136 Nothing -> throwError (show moduleName ++ "." ++ show ident ++ " is undefined")