Imports.hs 17.6 KB
Newer Older
Björn Peemöller 's avatar
Björn Peemöller committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
{- |
    Module      :  $Header$
    Description :  Importing interface declarations
    Copyright   :  (c) 2000-2003, Wolfgang Lux
                       2011, Björn Peemöller (bjp@informatik.uni-kiel.de)
    License     :  OtherLicense

    Maintainer  :  bjp@informatik.uni-kiel.de
    Stability   :  experimental
    Portability :  portable

    This module provides the function 'importModules' to bring the imported
    entities into the module's scope, and the function 'qualifyEnv' to
    qualify the environment prior to computing the export interface.
-}
module Imports (importModules, qualifyEnv) where

import qualified Data.Map as Map
import Data.Maybe
import qualified Data.Set as Set

import Curry.Base.Ident
import Curry.Syntax

import Base.CurryTypes (toQualType, toQualTypes)
26
import Base.Messages (Message, errorMessage, posErr, internalError)
27
import Base.TopEnv
Björn Peemöller 's avatar
Björn Peemöller committed
28
29
30
import Base.Types

import Env.Interface
Björn Peemöller 's avatar
Björn Peemöller committed
31
import Env.ModuleAlias (importAliases)
Björn Peemöller 's avatar
Björn Peemöller committed
32
33
34
35
36
37
import Env.OpPrec
import Env.TypeConstructors
import Env.Value

import CompilerEnv
import CompilerOpts
38
import Records (expandTCValueEnv, expandValueEnv)
Björn Peemöller 's avatar
Björn Peemöller committed
39
40
41

-- |The function 'importModules' brings the declarations of all
-- imported interfaces into scope for the current module.
42
43
importModules :: Options -> Module -> InterfaceEnv -> CompilerEnv
importModules opts (Module mid _ imps _) iEnv
44
  = expandTCValueEnv opts
45
46
  $ importUnifyData
  $ foldl importModule initEnv imps
Björn Peemöller 's avatar
Björn Peemöller committed
47
48
  where
    initEnv = (initCompilerEnv mid)
49
50
      { aliasEnv     = importAliases     imps -- import module aliases
      , interfaceEnv = iEnv                   -- imported interfaces
Björn Peemöller 's avatar
Björn Peemöller committed
51
52
      }
    importModule env (ImportDecl _ m q asM is) = case Map.lookup m iEnv of
53
54
55
      Just intf -> importInterface (fromMaybe m asM) q is intf env
      Nothing   -> internalError $ "Imports.importModules: no interface for "
                                   ++ show m
Björn Peemöller 's avatar
Björn Peemöller committed
56
57
58
59
60

-- ---------------------------------------------------------------------------
-- Importing an interface into the module
-- ---------------------------------------------------------------------------

61
-- Three kinds of environments are computed from the interface:
Björn Peemöller 's avatar
Björn Peemöller committed
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
--
-- 1. The operator precedences
-- 2. The type constructors
-- 3. The types of the data constructors and functions (values)
--
-- Note that the original names of all entities defined in the imported module
-- are qualified appropriately. The same is true for type expressions.

type IdentMap    = Map.Map Ident

type ExpPEnv     = IdentMap PrecInfo
type ExpTCEnv    = IdentMap TypeInfo
type ExpValueEnv = IdentMap ValueInfo

-- When an interface is imported, the compiler first transforms the
-- interface into these environments. If an import specification is
-- present, the environments are restricted to only those entities which
-- are included in the specification or not hidden by it, respectively.
-- The resulting environments are then imported into the current module
-- using either a qualified import (if the module is imported qualified)
-- or both a qualified and an unqualified import (non-qualified import).

importInterface :: ModuleIdent -> Bool -> Maybe ImportSpec -> Interface
                -> CompilerEnv -> CompilerEnv
importInterface m q is i env = env
  { opPrecEnv = importEntities m q vs id              mPEnv  $ opPrecEnv env
  , tyConsEnv = importEntities m q ts (importData vs) mTCEnv $ tyConsEnv env
  , valueEnv  = importEntities m q vs id              mTyEnv $ valueEnv  env
  }
Björn Peemöller 's avatar
Björn Peemöller committed
91
92
93
94
95
96
97
98
  where
  mPEnv  = intfEnv bindPrec i -- all operator precedences
  mTCEnv = intfEnv bindTC   i -- all type constructors
  mTyEnv = intfEnv bindTy   i -- all values
  -- all imported type constructors / values
  expandedSpec = maybe [] (expandSpecs m mTCEnv mTyEnv) is
  ts = isVisible is (Set.fromList $ foldr addType  [] expandedSpec)
  vs = isVisible is (Set.fromList $ foldr addValue [] expandedSpec)
Björn Peemöller 's avatar
Björn Peemöller committed
99

100
101
102
103
104
105
106
107
108
109
addType :: Import -> [Ident] -> [Ident]
addType (Import            _) tcs = tcs
addType (ImportTypeWith tc _) tcs = tc : tcs
addType (ImportTypeAll     _) _   = internalError "Imports.addType"

addValue :: Import -> [Ident] -> [Ident]
addValue (Import            f) fs = f : fs
addValue (ImportTypeWith _ cs) fs = cs ++ fs
addValue (ImportTypeAll     _) _  = internalError "Imports.addValue"

Björn Peemöller 's avatar
Björn Peemöller committed
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
isVisible :: Maybe ImportSpec -> Set.Set Ident -> Ident -> Bool
isVisible (Just (Importing _ _)) xs = (`Set.member`    xs)
isVisible (Just (Hiding    _ _)) xs = (`Set.notMember` xs)
isVisible Nothing                _  = const True

importEntities :: Entity a => ModuleIdent -> Bool -> (Ident -> Bool)
               -> (a -> a) -> IdentMap a -> TopEnv a -> TopEnv a
importEntities m q isVisible' f mEnv env =
  foldr (uncurry (if q then qualImportTopEnv m else importUnqual m)) env
        [(x,f y) | (x,y) <- Map.toList mEnv, isVisible' x]
  where importUnqual m' x y = importTopEnv m' x y . qualImportTopEnv m' x y

importData :: (Ident -> Bool) -> TypeInfo -> TypeInfo
importData isVisible' (DataType tc n cs) =
  DataType tc n (map (>>= importConstr isVisible') cs)
importData isVisible' (RenamingType tc n nc) =
  maybe (DataType tc n []) (RenamingType tc n) (importConstr isVisible' nc)
importData _ (AliasType tc n ty) = AliasType tc n ty

importConstr :: (Ident -> Bool) -> DataConstr -> Maybe DataConstr
importConstr isVisible' dc@(DataConstr c _ _)
  | isVisible' c = Just dc
  | otherwise    = Nothing

-- ---------------------------------------------------------------------------
-- Building the initial environment
-- ---------------------------------------------------------------------------

-- In a first step, the four export environments are initialized from
-- the interface's declarations. This step also qualifies the names of
-- all entities defined in (but not imported into) the interface with its
-- module name.

intfEnv :: (ModuleIdent -> IDecl -> IdentMap a -> IdentMap a)
        -> Interface -> IdentMap a
145
intfEnv bind (Interface m _ ds) = foldr (bind m) Map.empty ds
Björn Peemöller 's avatar
Björn Peemöller committed
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189

-- operator precedences
bindPrec :: ModuleIdent -> IDecl -> ExpPEnv -> ExpPEnv
bindPrec m (IInfixDecl _ fix p op) =
  Map.insert (unqualify op) (PrecInfo (qualQualify m op) (OpPrec fix p))
bindPrec _ _ = id

bindTCHidden :: ModuleIdent -> IDecl -> ExpTCEnv -> ExpTCEnv
bindTCHidden m (HidingDataDecl _ tc tvs) =
  bindType DataType m (qualify tc) tvs []
bindTCHidden m d = bindTC m d

-- type constructors
bindTC :: ModuleIdent -> IDecl -> ExpTCEnv -> ExpTCEnv
bindTC m (IDataDecl _ tc tvs cs) mTCEnv
  | unqualify tc `Map.member` mTCEnv = mTCEnv
  | otherwise = bindType DataType m tc tvs (map (fmap mkData) cs) mTCEnv
  where
   mkData (ConstrDecl _ evs c tys) =
     DataConstr c (length evs) (toQualTypes m tvs tys)
   mkData (ConOpDecl _ evs ty1 c ty2) =
     DataConstr c (length evs) (toQualTypes m tvs [ty1,ty2])

bindTC m (INewtypeDecl _ tc tvs (NewConstrDecl _ evs c ty)) mTCEnv =
  bindType RenamingType m tc tvs
 (DataConstr c (length evs) [toQualType m tvs ty]) mTCEnv

bindTC m (ITypeDecl _ tc tvs ty) mTCEnv
  | isRecordExtId tc' =
    bindType AliasType m (qualify (fromRecordExtId tc')) tvs
   (toQualType m tvs ty) mTCEnv
  | otherwise =
    bindType AliasType m tc tvs (toQualType m tvs ty) mTCEnv
  where tc' = unqualify tc

bindTC _ _ mTCEnv = mTCEnv

bindType :: (QualIdent -> Int -> a -> TypeInfo) -> ModuleIdent -> QualIdent
         -> [Ident] -> a -> ExpTCEnv -> ExpTCEnv
bindType f m tc tvs = Map.insert (unqualify tc)
                    . f (qualQualify m tc) (length tvs)

-- functions and data constructors
bindTy :: ModuleIdent -> IDecl -> ExpValueEnv -> ExpValueEnv
190
191
bindTy m (IDataDecl _ tc tvs cs) env =
  foldr (bindConstr m tc' tvs $ constrType tc' tvs) env $ catMaybes cs
Björn Peemöller 's avatar
Björn Peemöller committed
192
  where tc' = qualQualify m tc
193
194
bindTy m (INewtypeDecl _ tc tvs nc) env =
  bindNewConstr m tc' tvs (constrType tc' tvs) nc env
Björn Peemöller 's avatar
Björn Peemöller committed
195
  where tc' = qualQualify m tc
196
bindTy m (ITypeDecl _ r _ (RecordType fs _)) env =
197
  foldr (bindRecordLabels m r') env fs
198
199
200
201
  where r' = qualifyWith m $ fromRecordExtId $ unqualify r
bindTy m (IFunctionDecl _ f a ty) env = Map.insert (unqualify f)
  (Value (qualQualify m f) a (polyType (toQualType m [] ty))) env
bindTy _ _ env = env
Björn Peemöller 's avatar
Björn Peemöller committed
202
203
204

bindConstr :: ModuleIdent -> QualIdent -> [Ident] -> TypeExpr -> ConstrDecl
           -> ExpValueEnv -> ExpValueEnv
205
206
207
208
209
210
bindConstr m tc tvs ty0 (ConstrDecl _ evs c tys) = Map.insert c $
  DataConstructor (qualifyLike tc c) (length tys) $
  constrType' m tvs evs (foldr ArrowType ty0 tys)
bindConstr m tc tvs ty0 (ConOpDecl _ evs ty1 op ty2) = Map.insert op $
  DataConstructor (qualifyLike tc op) 2 $
  constrType' m tvs evs (ArrowType ty1 (ArrowType ty2 ty0))
Björn Peemöller 's avatar
Björn Peemöller committed
211
212
213

bindNewConstr :: ModuleIdent -> QualIdent -> [Ident] -> TypeExpr
              -> NewConstrDecl -> ExpValueEnv -> ExpValueEnv
214
215
216
217
218
219
220
221
222
223
224
bindNewConstr m tc tvs ty0 (NewConstrDecl _ evs c ty1) = Map.insert c $
  NewtypeConstructor (qualifyLike tc c) $
  constrType' m tvs evs (ArrowType ty1 ty0)

constrType' :: ModuleIdent -> [Ident] -> [Ident] -> TypeExpr -> ExistTypeScheme
constrType' m tvs evs ty = ForAllExist (length tvs) (length evs)
                                       (toQualType m tvs ty)

qualifyLike :: QualIdent -> Ident -> QualIdent
qualifyLike x = maybe qualify qualifyWith (qualidMod x)

225
226
227
bindRecordLabels :: ModuleIdent -> QualIdent -> ([Ident], TypeExpr)
                 -> ExpValueEnv -> ExpValueEnv
bindRecordLabels m r (ls, ty) env = foldr bindLbl env ls
228
  where
229
230
231
232
233
  bindLbl l = Map.insert l (lblInfo l)
  lblInfo l = Label (qualify l) r (polyType $ toQualType m [] ty)

constrType :: QualIdent -> [Ident] -> TypeExpr
constrType tc tvs = ConstructorType tc $ map VariableType tvs
Björn Peemöller 's avatar
Björn Peemöller committed
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274

-- ---------------------------------------------------------------------------
-- Expansion of the import specification
-- ---------------------------------------------------------------------------

-- After the environments have been initialized, the optional import
-- specifications can be checked. There are two kinds of import
-- specifications, a ``normal'' one, which names the entities that shall
-- be imported, and a hiding specification, which lists those entities
-- that shall not be imported.
--
-- There is a subtle difference between both kinds of
-- specifications: While it is not allowed to list a data constructor
-- outside of its type in a ``normal'' specification, it is allowed to
-- hide a data constructor explicitly. E.g., if module \texttt{A} exports
-- the data type \texttt{T} with constructor \texttt{C}, the data
-- constructor can be imported with one of the two specifications
--
-- import A (T(C))
-- import A (T(..))
--
-- but can be hidden in three different ways:
--
-- import A hiding (C)
-- import A hiding (T (C))
-- import A hiding (T (..))
--
-- The functions \texttt{expandImport} and \texttt{expandHiding} check
-- that all entities in an import specification are actually exported
-- from the module. In addition, all imports of type constructors are
-- changed into a \texttt{T()} specification and explicit imports for the
-- data constructors are added.

expandSpecs :: ModuleIdent -> ExpTCEnv -> ExpValueEnv -> ImportSpec
            -> [Import]
expandSpecs m tcEnv tyEnv (Importing _ is) =
  concatMap (expandImport m tcEnv tyEnv) is
expandSpecs m tcEnv tyEnv (Hiding _ is) =
  concatMap (expandHiding m tcEnv tyEnv) is

expandImport :: ModuleIdent -> ExpTCEnv -> ExpValueEnv -> Import -> [Import]
Björn Peemöller 's avatar
Björn Peemöller committed
275
276
277
278
279
280
expandImport m tcEnv tyEnv (Import             x) =
  expandThing m tcEnv tyEnv x
expandImport m tcEnv _     (ImportTypeWith tc cs) =
  [expandTypeWith m tcEnv tc cs]
expandImport m tcEnv _     (ImportTypeAll     tc) =
  [expandTypeAll  m tcEnv tc   ]
Björn Peemöller 's avatar
Björn Peemöller committed
281
282
283

expandHiding :: ModuleIdent -> ExpTCEnv -> ExpValueEnv -> Import -> [Import]
expandHiding m tcEnv tyEnv (Import             x) = expandHide m tcEnv tyEnv x
Björn Peemöller 's avatar
Björn Peemöller committed
284
285
286
287
expandHiding m tcEnv _     (ImportTypeWith tc cs) =
  [expandTypeWith m tcEnv tc cs]
expandHiding m tcEnv _     (ImportTypeAll     tc) =
  [expandTypeAll  m tcEnv tc   ]
Björn Peemöller 's avatar
Björn Peemöller committed
288
289
290
291
292
293
294
295

-- try to expand as type constructor
expandThing :: ModuleIdent -> ExpTCEnv -> ExpValueEnv -> Ident -> [Import]
expandThing m tcEnv tyEnv tc = case Map.lookup tc tcEnv of
  Just _  -> expandThing' m tyEnv tc $ Just [ImportTypeWith tc []]
  Nothing -> expandThing' m tyEnv tc Nothing

-- try to expand as function / data constructor
Björn Peemöller 's avatar
Björn Peemöller committed
296
297
expandThing' :: ModuleIdent -> ExpValueEnv -> Ident -> Maybe [Import]
             -> [Import]
Björn Peemöller 's avatar
Björn Peemöller committed
298
299
expandThing' m tyEnv f tcImport = case Map.lookup f tyEnv of
  Just v
300
    | isConstr v -> fromMaybe (errorMessage $ errImportDataConstr m f) tcImport
Björn Peemöller 's avatar
Björn Peemöller committed
301
    | otherwise  -> Import f : fromMaybe [] tcImport
302
303
  Nothing -> fromMaybe (errorMessage $ errUndefinedEntity m f) tcImport
  where isConstr (DataConstructor  _ _ _) = True
Björn Peemöller 's avatar
Björn Peemöller committed
304
        isConstr (NewtypeConstructor _ _) = True
305
        isConstr (Value            _ _ _) = False
Björn Peemöller 's avatar
Björn Peemöller committed
306
307
308
309
310
311
312
313
314
        isConstr (Label            _ _ _) = False

-- try to hide as type constructor
expandHide :: ModuleIdent -> ExpTCEnv -> ExpValueEnv -> Ident -> [Import]
expandHide m tcEnv tyEnv tc = case Map.lookup tc tcEnv of
  Just _  -> expandHide' m tyEnv tc $ Just [ImportTypeWith tc []]
  Nothing -> expandHide' m tyEnv tc Nothing

-- try to hide as function / data constructor
Björn Peemöller 's avatar
Björn Peemöller committed
315
316
expandHide' :: ModuleIdent -> ExpValueEnv -> Ident -> Maybe [Import]
            -> [Import]
Björn Peemöller 's avatar
Björn Peemöller committed
317
318
expandHide' m tyEnv f tcImport = case Map.lookup f tyEnv of
  Just _  -> Import f : fromMaybe [] tcImport
319
  Nothing -> fromMaybe (errorMessage $ errUndefinedEntity m f) tcImport
Björn Peemöller 's avatar
Björn Peemöller committed
320
321
322

expandTypeWith ::  ModuleIdent -> ExpTCEnv -> Ident -> [Ident] -> Import
expandTypeWith m tcEnv tc cs = case Map.lookup tc tcEnv of
323
324
325
326
327
328
329
330
  Just (DataType     _ _                cs') -> ImportTypeWith tc $
    map (checkConstr [c | Just (DataConstr c _ _) <- cs']) cs
  Just (RenamingType _ _ (DataConstr c _ _)) -> ImportTypeWith tc $
    map (checkConstr [c]) cs
  Just (AliasType    _ _ (TypeRecord  fs _)) -> ImportTypeWith tc $
    map (checkLabel [l | (l, _) <- fs] . renameLabel) cs
  Just (AliasType _ _ _) -> errorMessage $ errNonDataType tc
  Nothing                -> errorMessage $ errUndefinedEntity m tc
Björn Peemöller 's avatar
Björn Peemöller committed
331
  where
332
333
334
335
336
337
338
  checkConstr cs' c
    | c `elem` cs' = c
    | otherwise    = errorMessage $ errUndefinedDataConstr tc c
  checkLabel ls' l
    | l `elem` ls' = l
    | otherwise    = errorMessage $ errUndefinedLabel tc l

Björn Peemöller 's avatar
Björn Peemöller committed
339
340
341

expandTypeAll :: ModuleIdent -> ExpTCEnv -> Ident -> Import
expandTypeAll m tcEnv tc = case Map.lookup tc tcEnv of
342
343
344
345
346
347
348
349
  Just (DataType     _ _                 cs) -> ImportTypeWith tc
    [c | Just (DataConstr c _ _) <- cs]
  Just (RenamingType _ _ (DataConstr c _ _)) -> ImportTypeWith tc
    [c]
  Just (AliasType    _ _ (TypeRecord  fs _)) -> ImportTypeWith tc
    [l | (l, _) <- fs]
  Just (AliasType _ _ _) -> errorMessage $ errNonDataType tc
  Nothing                -> errorMessage $ errUndefinedEntity m tc
Björn Peemöller 's avatar
Björn Peemöller committed
350
351
352
353
354
355
356
357
358
359
360

-- ---------------------------------------------------------------------------

-- After all modules have been imported, the compiler has to ensure that
-- all references to a data type use the same list of constructors.

importUnifyData :: CompilerEnv -> CompilerEnv
importUnifyData cEnv = cEnv { tyConsEnv = importUnifyData' $ tyConsEnv cEnv }

importUnifyData' :: TCEnv -> TCEnv
importUnifyData' tcEnv = fmap (setInfo allTyCons) tcEnv
Björn Peemöller 's avatar
Björn Peemöller committed
361
362
363
364
365
366
  where
  setInfo tcs t   = fromJust $ Map.lookup (origName t) tcs
  allTyCons       = foldr (mergeData . snd) Map.empty $ allImports tcEnv
  mergeData t tcs =
    Map.insert tc (maybe t (fromJust . merge t) $ Map.lookup tc tcs) tcs
    where tc = origName t
Björn Peemöller 's avatar
Björn Peemöller committed
367
368
369

-- ---------------------------------------------------------------------------

Björn Peemöller 's avatar
Björn Peemöller committed
370
371
-- |
qualifyEnv :: Options -> CompilerEnv -> CompilerEnv
372
qualifyEnv opts env = expandValueEnv opts
Björn Peemöller 's avatar
Björn Peemöller committed
373
374
375
376
377
378
                    $ qualifyLocal env
                    $ foldl (flip importInterfaceIntf) initEnv
                    $ Map.elems
                    $ interfaceEnv env
  where initEnv = initCompilerEnv $ moduleIdent env

Björn Peemöller 's avatar
Björn Peemöller committed
379
380
381
382
383
384
385
386
387
388
qualifyLocal :: CompilerEnv -> CompilerEnv -> CompilerEnv
qualifyLocal currentEnv initEnv = currentEnv
  { opPrecEnv = foldr bindQual   pEnv  $ localBindings $ opPrecEnv currentEnv
  , tyConsEnv = foldr bindQual   tcEnv $ localBindings $ tyConsEnv currentEnv
  , valueEnv  = foldr bindGlobal tyEnv $ localBindings $ valueEnv  currentEnv
  }
  where
    pEnv  = opPrecEnv initEnv
    tcEnv = tyConsEnv initEnv
    tyEnv = valueEnv  initEnv
389
    bindQual   (_, y) = qualBindTopEnv "Modules.qualifyEnv" (origName y) y
Björn Peemöller 's avatar
Björn Peemöller committed
390
391
    bindGlobal (x, y)
      | uniqueId x == 0 = bindQual (x, y)
392
      | otherwise       = bindTopEnv "Modules.qualifyEnv" x y
Björn Peemöller 's avatar
Björn Peemöller committed
393
394
395
396
397
398
399
400

-- Importing an interface into another interface is somewhat simpler
-- because all entities are imported into the environment. In addition,
-- only a qualified import is necessary. Note that the hidden data types
-- are imported as well because they may be used in type expressions in
-- an interface.

importInterfaceIntf :: Interface -> CompilerEnv -> CompilerEnv
401
importInterfaceIntf i@(Interface m _ _) env = env
Björn Peemöller 's avatar
Björn Peemöller committed
402
403
404
405
  { opPrecEnv = importEntities m True (const True) id mPEnv  $ opPrecEnv env
  , tyConsEnv = importEntities m True (const True) id mTCEnv $ tyConsEnv env
  , valueEnv  = importEntities m True (const True) id mTyEnv $ valueEnv  env
  }
Björn Peemöller 's avatar
Björn Peemöller committed
406
407
408
409
  where
  mPEnv  = intfEnv bindPrec       i -- all operator precedences
  mTCEnv = intfEnv bindTCHidden   i -- all type constructors
  mTyEnv = intfEnv bindTy         i -- all values
Björn Peemöller 's avatar
Björn Peemöller committed
410
411
412

-- Error messages:

413
414
errUndefinedEntity :: ModuleIdent -> Ident -> Message
errUndefinedEntity m x = posErr x $
Björn Peemöller 's avatar
Björn Peemöller committed
415
416
  "Module " ++ moduleName m ++ " does not export " ++ name x

417
418
errUndefinedDataConstr :: Ident -> Ident -> Message
errUndefinedDataConstr tc c = posErr c $
Björn Peemöller 's avatar
Björn Peemöller committed
419
420
  name c ++ " is not a data constructor of type " ++ name tc

421
422
423
424
errUndefinedLabel :: Ident -> Ident -> Message
errUndefinedLabel tc c = posErr c $
  name c ++ " is not a label of record type " ++ name tc

425
426
errNonDataType :: Ident -> Message
errNonDataType tc = posErr tc $ name tc ++ " is not a data type"
Björn Peemöller 's avatar
Björn Peemöller committed
427

428
429
errImportDataConstr :: ModuleIdent -> Ident -> Message
errImportDataConstr _ c = posErr c $
Björn Peemöller 's avatar
Björn Peemöller committed
430
  "Explicit import for data constructor " ++ name c