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 ++ ": ") ++) $ 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 ++ ": ") ++) $ 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 = PolyType 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 ++ ": ") ++) $ 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 ++ ": ") ++) $ 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 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 ++ ": ") ++) $ 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 (PolyType _ (Function [_] _)) -> do
98 putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env)
99 , members = M.insert (modulePath, name) member (members env) })
100 _ -> throwError "Foreign member declarations must have function types, with an single argument."
101 typeCheckAll rest
102typeCheckAll (ExternDeclaration name ty : rest) = do
103 rethrow (("Error in foreign import declaration " ++ show name ++ ": ") ++) $ do
104 env <- getEnv
105 modulePath <- checkModulePath `fmap` get
106 kind <- kindOf ty
107 guardWith "Expected kind *" $ kind == Star
108 case M.lookup (modulePath, name) (names env) of
109 Just _ -> throwError $ show name ++ " is already defined"
110 Nothing -> putEnv (env { names = M.insert (modulePath, name) (ty, Extern) (names env) })
111 typeCheckAll rest
112typeCheckAll (FixityDeclaration _ name : rest) = do
113 typeCheckAll rest
114 env <- getEnv
115 modulePath <- checkModulePath `fmap` get
116 guardWith ("Fixity declaration with no binding: " ++ name) $ M.member (modulePath, Op name) $ names env
117typeCheckAll (ModuleDeclaration name decls : rest) = do
118 withModule name $ typeCheckAll decls
119 typeCheckAll rest
120typeCheckAll (ImportDeclaration modulePath idents : rest) = do
121 env <- getEnv
122 omp <- checkModulePath `fmap` get
123 rethrow errorMessage $
124 guardWith "module does not exist" $ moduleExists env
125 case idents of
126 Nothing -> do
127 let idents = map snd $ filterModule env
128 rethrow errorMessage $
129 bindIdents idents omp env
130 typeCheckAll rest
131 Just idents -> do
132 rethrow errorMessage $
133 bindIdents idents omp env
134 typeCheckAll rest
135 where errorMessage = (("Error importing " ++ show modulePath ++ ": ") ++)
136 filterModule env = filter (\(m, _) -> m == modulePath) (M.keys (names env))
137 moduleExists env = not $ null $ filterModule env
138 bindIdents idents omp env =
139 forM_ idents $ \ident ->
140 case M.lookup (modulePath, ident) (names env) of
141 Nothing -> throwError $ show modulePath ++ "." ++ show ident ++ " is undefined"
142 Just (pt, _) -> getEnv >>= \env' ->
143 putEnv (env' { names = M.insert (omp, ident) (pt, Alias modulePath ident) (names env') })