4c060de29f9e11f4689ce119e67ff0ffa3b192c4
[ghc.git] / compiler / deSugar / DsMeta.hs
1 {-# LANGUAGE CPP #-}
2
3 -----------------------------------------------------------------------------
4 --
5 -- (c) The University of Glasgow 2006
6 --
7 -- The purpose of this module is to transform an HsExpr into a CoreExpr which
8 -- when evaluated, returns a (Meta.Q Meta.Exp) computation analogous to the
9 -- input HsExpr. We do this in the DsM monad, which supplies access to
10 -- CoreExpr's of the "smart constructors" of the Meta.Exp datatype.
11 --
12 -- It also defines a bunch of knownKeyNames, in the same way as is done
13 -- in prelude/PrelNames. It's much more convenient to do it here, because
14 -- otherwise we have to recompile PrelNames whenever we add a Name, which is
15 -- a Royal Pain (triggers other recompilation).
16 -----------------------------------------------------------------------------
17
18 module DsMeta( dsBracket ) where
19
20 #include "HsVersions.h"
21
22 import {-# SOURCE #-} DsExpr ( dsExpr )
23
24 import MatchLit
25 import DsMonad
26
27 import qualified Language.Haskell.TH as TH
28
29 import HsSyn
30 import Class
31 import PrelNames
32 -- To avoid clashes with DsMeta.varName we must make a local alias for
33 -- OccName.varName we do this by removing varName from the import of
34 -- OccName above, making a qualified instance of OccName and using
35 -- OccNameAlias.varName where varName ws previously used in this file.
36 import qualified OccName( isDataOcc, isVarOcc, isTcOcc )
37
38 import Module
39 import Id
40 import Name hiding( isVarOcc, isTcOcc, varName, tcName )
41 import THNames
42 import NameEnv
43 import TcType
44 import TyCon
45 import TysWiredIn
46 import TysPrim ( liftedTypeKindTyConName, constraintKindTyConName )
47 import CoreSyn
48 import MkCore
49 import CoreUtils
50 import SrcLoc
51 import Unique
52 import BasicTypes
53 import Outputable
54 import Bag
55 import DynFlags
56 import FastString
57 import ForeignCall
58 import Util
59 import Maybes
60 import MonadUtils
61
62 import Data.ByteString ( unpack )
63 import Control.Monad
64 import Data.List
65
66 -----------------------------------------------------------------------------
67 dsBracket :: HsBracket Name -> [PendingTcSplice] -> DsM CoreExpr
68 -- Returns a CoreExpr of type TH.ExpQ
69 -- The quoted thing is parameterised over Name, even though it has
70 -- been type checked. We don't want all those type decorations!
71
72 dsBracket brack splices
73 = dsExtendMetaEnv new_bit (do_brack brack)
74 where
75 new_bit = mkNameEnv [(n, DsSplice (unLoc e)) | PendingTcSplice n e <- splices]
76
77 do_brack (VarBr _ n) = do { MkC e1 <- lookupOcc n ; return e1 }
78 do_brack (ExpBr e) = do { MkC e1 <- repLE e ; return e1 }
79 do_brack (PatBr p) = do { MkC p1 <- repTopP p ; return p1 }
80 do_brack (TypBr t) = do { MkC t1 <- repLTy t ; return t1 }
81 do_brack (DecBrG gp) = do { MkC ds1 <- repTopDs gp ; return ds1 }
82 do_brack (DecBrL _) = panic "dsBracket: unexpected DecBrL"
83 do_brack (TExpBr e) = do { MkC e1 <- repLE e ; return e1 }
84
85 {- -------------- Examples --------------------
86
87 [| \x -> x |]
88 ====>
89 gensym (unpackString "x"#) `bindQ` \ x1::String ->
90 lam (pvar x1) (var x1)
91
92
93 [| \x -> $(f [| x |]) |]
94 ====>
95 gensym (unpackString "x"#) `bindQ` \ x1::String ->
96 lam (pvar x1) (f (var x1))
97 -}
98
99
100 -------------------------------------------------------
101 -- Declarations
102 -------------------------------------------------------
103
104 repTopP :: LPat Name -> DsM (Core TH.PatQ)
105 repTopP pat = do { ss <- mkGenSyms (collectPatBinders pat)
106 ; pat' <- addBinds ss (repLP pat)
107 ; wrapGenSyms ss pat' }
108
109 repTopDs :: HsGroup Name -> DsM (Core (TH.Q [TH.Dec]))
110 repTopDs group@(HsGroup { hs_valds = valds
111 , hs_splcds = splcds
112 , hs_tyclds = tyclds
113 , hs_instds = instds
114 , hs_derivds = derivds
115 , hs_fixds = fixds
116 , hs_defds = defds
117 , hs_fords = fords
118 , hs_warnds = warnds
119 , hs_annds = annds
120 , hs_ruleds = ruleds
121 , hs_vects = vects
122 , hs_docs = docs })
123 = do { let { tv_bndrs = hsSigTvBinders valds
124 ; bndrs = tv_bndrs ++ hsGroupBinders group } ;
125 ss <- mkGenSyms bndrs ;
126
127 -- Bind all the names mainly to avoid repeated use of explicit strings.
128 -- Thus we get
129 -- do { t :: String <- genSym "T" ;
130 -- return (Data t [] ...more t's... }
131 -- The other important reason is that the output must mention
132 -- only "T", not "Foo:T" where Foo is the current module
133
134 decls <- addBinds ss (
135 do { val_ds <- rep_val_binds valds
136 ; _ <- mapM no_splice splcds
137 ; tycl_ds <- mapM repTyClD (tyClGroupConcat tyclds)
138 ; role_ds <- mapM repRoleD (concatMap group_roles tyclds)
139 ; inst_ds <- mapM repInstD instds
140 ; deriv_ds <- mapM repStandaloneDerivD derivds
141 ; fix_ds <- mapM repFixD fixds
142 ; _ <- mapM no_default_decl defds
143 ; for_ds <- mapM repForD fords
144 ; _ <- mapM no_warn (concatMap (wd_warnings . unLoc)
145 warnds)
146 ; ann_ds <- mapM repAnnD annds
147 ; rule_ds <- mapM repRuleD (concatMap (rds_rules . unLoc)
148 ruleds)
149 ; _ <- mapM no_vect vects
150 ; _ <- mapM no_doc docs
151
152 -- more needed
153 ; return (de_loc $ sort_by_loc $
154 val_ds ++ catMaybes tycl_ds ++ role_ds
155 ++ (concat fix_ds)
156 ++ inst_ds ++ rule_ds ++ for_ds
157 ++ ann_ds ++ deriv_ds) }) ;
158
159 decl_ty <- lookupType decQTyConName ;
160 let { core_list = coreList' decl_ty decls } ;
161
162 dec_ty <- lookupType decTyConName ;
163 q_decs <- repSequenceQ dec_ty core_list ;
164
165 wrapGenSyms ss q_decs
166 }
167 where
168 no_splice (L loc _)
169 = notHandledL loc "Splices within declaration brackets" empty
170 no_default_decl (L loc decl)
171 = notHandledL loc "Default declarations" (ppr decl)
172 no_warn (L loc (Warning thing _))
173 = notHandledL loc "WARNING and DEPRECATION pragmas" $
174 text "Pragma for declaration of" <+> ppr thing
175 no_vect (L loc decl)
176 = notHandledL loc "Vectorisation pragmas" (ppr decl)
177 no_doc (L loc _)
178 = notHandledL loc "Haddock documentation" empty
179
180 hsSigTvBinders :: HsValBinds Name -> [Name]
181 -- See Note [Scoped type variables in bindings]
182 hsSigTvBinders binds
183 = [hsLTyVarName tv | L _ (TypeSig _ (L _ (HsForAllTy Explicit _ qtvs _ _)) _) <- sigs
184 , tv <- hsQTvBndrs qtvs]
185 where
186 sigs = case binds of
187 ValBindsIn _ sigs -> sigs
188 ValBindsOut _ sigs -> sigs
189
190
191 {- Notes
192
193 Note [Scoped type variables in bindings]
194 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
195 Consider
196 f :: forall a. a -> a
197 f x = x::a
198 Here the 'forall a' brings 'a' into scope over the binding group.
199 To achieve this we
200
201 a) Gensym a binding for 'a' at the same time as we do one for 'f'
202 collecting the relevant binders with hsSigTvBinders
203
204 b) When processing the 'forall', don't gensym
205
206 The relevant places are signposted with references to this Note
207
208 Note [Binders and occurrences]
209 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
210 When we desugar [d| data T = MkT |]
211 we want to get
212 Data "T" [] [Con "MkT" []] []
213 and *not*
214 Data "Foo:T" [] [Con "Foo:MkT" []] []
215 That is, the new data decl should fit into whatever new module it is
216 asked to fit in. We do *not* clone, though; no need for this:
217 Data "T79" ....
218
219 But if we see this:
220 data T = MkT
221 foo = reifyDecl T
222
223 then we must desugar to
224 foo = Data "Foo:T" [] [Con "Foo:MkT" []] []
225
226 So in repTopDs we bring the binders into scope with mkGenSyms and addBinds.
227 And we use lookupOcc, rather than lookupBinder
228 in repTyClD and repC.
229
230 -}
231
232 -- represent associated family instances
233 --
234 repTyClD :: LTyClDecl Name -> DsM (Maybe (SrcSpan, Core TH.DecQ))
235
236 repTyClD (L loc (FamDecl { tcdFam = fam })) = liftM Just $ repFamilyDecl (L loc fam)
237
238 repTyClD (L loc (SynDecl { tcdLName = tc, tcdTyVars = tvs, tcdRhs = rhs }))
239 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
240 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
241 repSynDecl tc1 bndrs rhs
242 ; return (Just (loc, dec)) }
243
244 repTyClD (L loc (DataDecl { tcdLName = tc, tcdTyVars = tvs, tcdDataDefn = defn }))
245 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
246 ; tc_tvs <- mk_extra_tvs tc tvs defn
247 ; dec <- addTyClTyVarBinds tc_tvs $ \bndrs ->
248 repDataDefn tc1 bndrs Nothing (hsLTyVarNames tc_tvs) defn
249 ; return (Just (loc, dec)) }
250
251 repTyClD (L loc (ClassDecl { tcdCtxt = cxt, tcdLName = cls,
252 tcdTyVars = tvs, tcdFDs = fds,
253 tcdSigs = sigs, tcdMeths = meth_binds,
254 tcdATs = ats, tcdATDefs = atds }))
255 = do { cls1 <- lookupLOcc cls -- See note [Binders and occurrences]
256 ; dec <- addTyVarBinds tvs $ \bndrs ->
257 do { cxt1 <- repLContext cxt
258 ; sigs1 <- rep_sigs sigs
259 ; binds1 <- rep_binds meth_binds
260 ; fds1 <- repLFunDeps fds
261 ; ats1 <- repFamilyDecls ats
262 ; atds1 <- repAssocTyFamDefaults atds
263 ; decls1 <- coreList decQTyConName (ats1 ++ atds1 ++ sigs1 ++ binds1)
264 ; repClass cxt1 cls1 bndrs fds1 decls1
265 }
266 ; return $ Just (loc, dec)
267 }
268
269 -------------------------
270 repRoleD :: LRoleAnnotDecl Name -> DsM (SrcSpan, Core TH.DecQ)
271 repRoleD (L loc (RoleAnnotDecl tycon roles))
272 = do { tycon1 <- lookupLOcc tycon
273 ; roles1 <- mapM repRole roles
274 ; roles2 <- coreList roleTyConName roles1
275 ; dec <- repRoleAnnotD tycon1 roles2
276 ; return (loc, dec) }
277
278 -------------------------
279 repDataDefn :: Core TH.Name -> Core [TH.TyVarBndr]
280 -> Maybe (Core [TH.TypeQ])
281 -> [Name] -> HsDataDefn Name
282 -> DsM (Core TH.DecQ)
283 repDataDefn tc bndrs opt_tys tv_names
284 (HsDataDefn { dd_ND = new_or_data, dd_ctxt = cxt
285 , dd_cons = cons, dd_derivs = mb_derivs })
286 = do { cxt1 <- repLContext cxt
287 ; derivs1 <- repDerivs mb_derivs
288 ; case new_or_data of
289 NewType -> do { con1 <- repC tv_names (head cons)
290 ; case con1 of
291 [c] -> repNewtype cxt1 tc bndrs opt_tys c derivs1
292 _cs -> failWithDs (ptext
293 (sLit "Multiple constructors for newtype:")
294 <+> pprQuotedList
295 (con_names $ unLoc $ head cons))
296 }
297 DataType -> do { consL <- concatMapM (repC tv_names) cons
298 ; cons1 <- coreList conQTyConName consL
299 ; repData cxt1 tc bndrs opt_tys cons1 derivs1 } }
300
301 repSynDecl :: Core TH.Name -> Core [TH.TyVarBndr]
302 -> LHsType Name
303 -> DsM (Core TH.DecQ)
304 repSynDecl tc bndrs ty
305 = do { ty1 <- repLTy ty
306 ; repTySyn tc bndrs ty1 }
307
308 repFamilyDecl :: LFamilyDecl Name -> DsM (SrcSpan, Core TH.DecQ)
309 repFamilyDecl decl@(L loc (FamilyDecl { fdInfo = info,
310 fdLName = tc,
311 fdTyVars = tvs,
312 fdResultSig = L _ resultSig,
313 fdInjectivityAnn = injectivity }))
314 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
315 ; let mkHsQTvs tvs = HsQTvs { hsq_kvs = [], hsq_tvs = tvs }
316 resTyVar = case resultSig of
317 TyVarSig bndr -> mkHsQTvs [bndr]
318 _ -> mkHsQTvs []
319 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
320 addTyClTyVarBinds resTyVar $ \_ ->
321 case info of
322 ClosedTypeFamily Nothing ->
323 notHandled "abstract closed type family" (ppr decl)
324 ClosedTypeFamily (Just eqns) ->
325 do { eqns1 <- mapM repTyFamEqn eqns
326 ; eqns2 <- coreList tySynEqnQTyConName eqns1
327 ; result <- repFamilyResultSig resultSig
328 ; inj <- repInjectivityAnn injectivity
329 ; repClosedFamilyD tc1 bndrs result inj eqns2 }
330 OpenTypeFamily ->
331 do { result <- repFamilyResultSig resultSig
332 ; inj <- repInjectivityAnn injectivity
333 ; repOpenFamilyD tc1 bndrs result inj }
334 DataFamily ->
335 do { kind <- repFamilyResultSigToMaybeKind resultSig
336 ; repDataFamilyD tc1 bndrs kind }
337 ; return (loc, dec)
338 }
339
340 -- | Represent result signature of a type family
341 repFamilyResultSig :: FamilyResultSig Name -> DsM (Core TH.FamilyResultSig)
342 repFamilyResultSig NoSig = repNoSig
343 repFamilyResultSig (KindSig ki) = do { ki' <- repLKind ki
344 ; repKindSig ki' }
345 repFamilyResultSig (TyVarSig bndr) = do { bndr' <- repTyVarBndr bndr
346 ; repTyVarSig bndr' }
347
348 -- | Represent result signature using a Maybe Kind. Used with data families,
349 -- where the result signature can be either missing or a kind but never a named
350 -- result variable.
351 repFamilyResultSigToMaybeKind :: FamilyResultSig Name
352 -> DsM (Core (Maybe TH.Kind))
353 repFamilyResultSigToMaybeKind NoSig =
354 do { coreNothing kindTyConName }
355 repFamilyResultSigToMaybeKind (KindSig ki) =
356 do { ki' <- repLKind ki
357 ; coreJust kindTyConName ki' }
358 repFamilyResultSigToMaybeKind _ = panic "repFamilyResultSigToMaybeKind"
359
360 -- | Represent injectivity annotation of a type family
361 repInjectivityAnn :: Maybe (LInjectivityAnn Name)
362 -> DsM (Core (Maybe TH.InjectivityAnn))
363 repInjectivityAnn Nothing =
364 do { coreNothing injAnnTyConName }
365 repInjectivityAnn (Just (L _ (InjectivityAnn lhs rhs))) =
366 do { lhs' <- lookupBinder (unLoc lhs)
367 ; rhs1 <- mapM (lookupBinder . unLoc) rhs
368 ; rhs2 <- coreList nameTyConName rhs1
369 ; injAnn <- rep2 injectivityAnnName [unC lhs', unC rhs2]
370 ; coreJust injAnnTyConName injAnn }
371
372 repFamilyDecls :: [LFamilyDecl Name] -> DsM [Core TH.DecQ]
373 repFamilyDecls fds = liftM de_loc (mapM repFamilyDecl fds)
374
375 repAssocTyFamDefaults :: [LTyFamDefltEqn Name] -> DsM [Core TH.DecQ]
376 repAssocTyFamDefaults = mapM rep_deflt
377 where
378 -- very like repTyFamEqn, but different in the details
379 rep_deflt :: LTyFamDefltEqn Name -> DsM (Core TH.DecQ)
380 rep_deflt (L _ (TyFamEqn { tfe_tycon = tc
381 , tfe_pats = bndrs
382 , tfe_rhs = rhs }))
383 = addTyClTyVarBinds bndrs $ \ _ ->
384 do { tc1 <- lookupLOcc tc
385 ; tys1 <- repLTys (hsLTyVarBndrsToTypes bndrs)
386 ; tys2 <- coreList typeQTyConName tys1
387 ; rhs1 <- repLTy rhs
388 ; eqn1 <- repTySynEqn tys2 rhs1
389 ; repTySynInst tc1 eqn1 }
390
391 -------------------------
392 mk_extra_tvs :: Located Name -> LHsTyVarBndrs Name
393 -> HsDataDefn Name -> DsM (LHsTyVarBndrs Name)
394 -- If there is a kind signature it must be of form
395 -- k1 -> .. -> kn -> *
396 -- Return type variables [tv1:k1, tv2:k2, .., tvn:kn]
397 mk_extra_tvs tc tvs defn
398 | HsDataDefn { dd_kindSig = Just hs_kind } <- defn
399 = do { extra_tvs <- go hs_kind
400 ; return (tvs { hsq_tvs = hsq_tvs tvs ++ extra_tvs }) }
401 | otherwise
402 = return tvs
403 where
404 go :: LHsKind Name -> DsM [LHsTyVarBndr Name]
405 go (L loc (HsFunTy kind rest))
406 = do { uniq <- newUnique
407 ; let { occ = mkTyVarOccFS (fsLit "t")
408 ; nm = mkInternalName uniq occ loc
409 ; hs_tv = L loc (KindedTyVar (noLoc nm) kind) }
410 ; hs_tvs <- go rest
411 ; return (hs_tv : hs_tvs) }
412
413 go (L _ (HsTyVar n))
414 | n == liftedTypeKindTyConName
415 = return []
416
417 go _ = failWithDs (ptext (sLit "Malformed kind signature for") <+> ppr tc)
418
419 -------------------------
420 -- represent fundeps
421 --
422 repLFunDeps :: [Located (FunDep (Located Name))] -> DsM (Core [TH.FunDep])
423 repLFunDeps fds = repList funDepTyConName repLFunDep fds
424
425 repLFunDep :: Located (FunDep (Located Name)) -> DsM (Core TH.FunDep)
426 repLFunDep (L _ (xs, ys))
427 = do xs' <- repList nameTyConName (lookupBinder . unLoc) xs
428 ys' <- repList nameTyConName (lookupBinder . unLoc) ys
429 repFunDep xs' ys'
430
431 -- Represent instance declarations
432 --
433 repInstD :: LInstDecl Name -> DsM (SrcSpan, Core TH.DecQ)
434 repInstD (L loc (TyFamInstD { tfid_inst = fi_decl }))
435 = do { dec <- repTyFamInstD fi_decl
436 ; return (loc, dec) }
437 repInstD (L loc (DataFamInstD { dfid_inst = fi_decl }))
438 = do { dec <- repDataFamInstD fi_decl
439 ; return (loc, dec) }
440 repInstD (L loc (ClsInstD { cid_inst = cls_decl }))
441 = do { dec <- repClsInstD cls_decl
442 ; return (loc, dec) }
443
444 repClsInstD :: ClsInstDecl Name -> DsM (Core TH.DecQ)
445 repClsInstD (ClsInstDecl { cid_poly_ty = ty, cid_binds = binds
446 , cid_sigs = prags, cid_tyfam_insts = ats
447 , cid_datafam_insts = adts })
448 = addTyVarBinds tvs $ \_ ->
449 -- We must bring the type variables into scope, so their
450 -- occurrences don't fail, even though the binders don't
451 -- appear in the resulting data structure
452 --
453 -- But we do NOT bring the binders of 'binds' into scope
454 -- because they are properly regarded as occurrences
455 -- For example, the method names should be bound to
456 -- the selector Ids, not to fresh names (Trac #5410)
457 --
458 do { cxt1 <- repContext cxt
459 ; cls_tcon <- repTy (HsTyVar (unLoc cls))
460 ; cls_tys <- repLTys tys
461 ; inst_ty1 <- repTapps cls_tcon cls_tys
462 ; binds1 <- rep_binds binds
463 ; prags1 <- rep_sigs prags
464 ; ats1 <- mapM (repTyFamInstD . unLoc) ats
465 ; adts1 <- mapM (repDataFamInstD . unLoc) adts
466 ; decls <- coreList decQTyConName (ats1 ++ adts1 ++ binds1 ++ prags1)
467 ; repInst cxt1 inst_ty1 decls }
468 where
469 Just (tvs, cxt, cls, tys) = splitLHsInstDeclTy_maybe ty
470
471 repStandaloneDerivD :: LDerivDecl Name -> DsM (SrcSpan, Core TH.DecQ)
472 repStandaloneDerivD (L loc (DerivDecl { deriv_type = ty }))
473 = do { dec <- addTyVarBinds tvs $ \_ ->
474 do { cxt' <- repContext cxt
475 ; cls_tcon <- repTy (HsTyVar (unLoc cls))
476 ; cls_tys <- repLTys tys
477 ; inst_ty <- repTapps cls_tcon cls_tys
478 ; repDeriv cxt' inst_ty }
479 ; return (loc, dec) }
480 where
481 Just (tvs, cxt, cls, tys) = splitLHsInstDeclTy_maybe ty
482
483 repTyFamInstD :: TyFamInstDecl Name -> DsM (Core TH.DecQ)
484 repTyFamInstD decl@(TyFamInstDecl { tfid_eqn = eqn })
485 = do { let tc_name = tyFamInstDeclLName decl
486 ; tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
487 ; eqn1 <- repTyFamEqn eqn
488 ; repTySynInst tc eqn1 }
489
490 repTyFamEqn :: LTyFamInstEqn Name -> DsM (Core TH.TySynEqnQ)
491 repTyFamEqn (L loc (TyFamEqn { tfe_pats = HsWB { hswb_cts = tys
492 , hswb_kvs = kv_names
493 , hswb_tvs = tv_names }
494 , tfe_rhs = rhs }))
495 = do { let hs_tvs = HsQTvs { hsq_kvs = kv_names
496 , hsq_tvs = userHsTyVarBndrs loc tv_names } -- Yuk
497 ; addTyClTyVarBinds hs_tvs $ \ _ ->
498 do { tys1 <- repLTys tys
499 ; tys2 <- coreList typeQTyConName tys1
500 ; rhs1 <- repLTy rhs
501 ; repTySynEqn tys2 rhs1 } }
502
503 repDataFamInstD :: DataFamInstDecl Name -> DsM (Core TH.DecQ)
504 repDataFamInstD (DataFamInstDecl { dfid_tycon = tc_name
505 , dfid_pats = HsWB { hswb_cts = tys, hswb_kvs = kv_names, hswb_tvs = tv_names }
506 , dfid_defn = defn })
507 = do { tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
508 ; let loc = getLoc tc_name
509 hs_tvs = HsQTvs { hsq_kvs = kv_names, hsq_tvs = userHsTyVarBndrs loc tv_names } -- Yuk
510 ; addTyClTyVarBinds hs_tvs $ \ bndrs ->
511 do { tys1 <- repList typeQTyConName repLTy tys
512 ; repDataDefn tc bndrs (Just tys1) tv_names defn } }
513
514 repForD :: Located (ForeignDecl Name) -> DsM (SrcSpan, Core TH.DecQ)
515 repForD (L loc (ForeignImport name typ _ (CImport (L _ cc) (L _ s) mch cis _)))
516 = do MkC name' <- lookupLOcc name
517 MkC typ' <- repLTy typ
518 MkC cc' <- repCCallConv cc
519 MkC s' <- repSafety s
520 cis' <- conv_cimportspec cis
521 MkC str <- coreStringLit (static ++ chStr ++ cis')
522 dec <- rep2 forImpDName [cc', s', str, name', typ']
523 return (loc, dec)
524 where
525 conv_cimportspec (CLabel cls) = notHandled "Foreign label" (doubleQuotes (ppr cls))
526 conv_cimportspec (CFunction DynamicTarget) = return "dynamic"
527 conv_cimportspec (CFunction (StaticTarget _ fs _ True))
528 = return (unpackFS fs)
529 conv_cimportspec (CFunction (StaticTarget _ _ _ False))
530 = panic "conv_cimportspec: values not supported yet"
531 conv_cimportspec CWrapper = return "wrapper"
532 -- these calling conventions do not support headers and the static keyword
533 raw_cconv = cc == PrimCallConv || cc == JavaScriptCallConv
534 static = case cis of
535 CFunction (StaticTarget _ _ _ _) | not raw_cconv -> "static "
536 _ -> ""
537 chStr = case mch of
538 Just (Header _ h) | not raw_cconv -> unpackFS h ++ " "
539 _ -> ""
540 repForD decl = notHandled "Foreign declaration" (ppr decl)
541
542 repCCallConv :: CCallConv -> DsM (Core TH.Callconv)
543 repCCallConv CCallConv = rep2 cCallName []
544 repCCallConv StdCallConv = rep2 stdCallName []
545 repCCallConv CApiConv = rep2 cApiCallName []
546 repCCallConv PrimCallConv = rep2 primCallName []
547 repCCallConv JavaScriptCallConv = rep2 javaScriptCallName []
548
549 repSafety :: Safety -> DsM (Core TH.Safety)
550 repSafety PlayRisky = rep2 unsafeName []
551 repSafety PlayInterruptible = rep2 interruptibleName []
552 repSafety PlaySafe = rep2 safeName []
553
554 repFixD :: LFixitySig Name -> DsM [(SrcSpan, Core TH.DecQ)]
555 repFixD (L loc (FixitySig names (Fixity prec dir)))
556 = do { MkC prec' <- coreIntLit prec
557 ; let rep_fn = case dir of
558 InfixL -> infixLDName
559 InfixR -> infixRDName
560 InfixN -> infixNDName
561 ; let do_one name
562 = do { MkC name' <- lookupLOcc name
563 ; dec <- rep2 rep_fn [prec', name']
564 ; return (loc,dec) }
565 ; mapM do_one names }
566
567 repRuleD :: LRuleDecl Name -> DsM (SrcSpan, Core TH.DecQ)
568 repRuleD (L loc (HsRule n act bndrs lhs _ rhs _))
569 = do { let bndr_names = concatMap ruleBndrNames bndrs
570 ; ss <- mkGenSyms bndr_names
571 ; rule1 <- addBinds ss $
572 do { bndrs' <- repList ruleBndrQTyConName repRuleBndr bndrs
573 ; n' <- coreStringLit $ unpackFS $ snd $ unLoc n
574 ; act' <- repPhases act
575 ; lhs' <- repLE lhs
576 ; rhs' <- repLE rhs
577 ; repPragRule n' bndrs' lhs' rhs' act' }
578 ; rule2 <- wrapGenSyms ss rule1
579 ; return (loc, rule2) }
580
581 ruleBndrNames :: LRuleBndr Name -> [Name]
582 ruleBndrNames (L _ (RuleBndr n)) = [unLoc n]
583 ruleBndrNames (L _ (RuleBndrSig n (HsWB { hswb_kvs = kvs, hswb_tvs = tvs })))
584 = unLoc n : kvs ++ tvs
585
586 repRuleBndr :: LRuleBndr Name -> DsM (Core TH.RuleBndrQ)
587 repRuleBndr (L _ (RuleBndr n))
588 = do { MkC n' <- lookupLBinder n
589 ; rep2 ruleVarName [n'] }
590 repRuleBndr (L _ (RuleBndrSig n (HsWB { hswb_cts = ty })))
591 = do { MkC n' <- lookupLBinder n
592 ; MkC ty' <- repLTy ty
593 ; rep2 typedRuleVarName [n', ty'] }
594
595 repAnnD :: LAnnDecl Name -> DsM (SrcSpan, Core TH.DecQ)
596 repAnnD (L loc (HsAnnotation _ ann_prov (L _ exp)))
597 = do { target <- repAnnProv ann_prov
598 ; exp' <- repE exp
599 ; dec <- repPragAnn target exp'
600 ; return (loc, dec) }
601
602 repAnnProv :: AnnProvenance Name -> DsM (Core TH.AnnTarget)
603 repAnnProv (ValueAnnProvenance (L _ n))
604 = do { MkC n' <- globalVar n -- ANNs are allowed only at top-level
605 ; rep2 valueAnnotationName [ n' ] }
606 repAnnProv (TypeAnnProvenance (L _ n))
607 = do { MkC n' <- globalVar n
608 ; rep2 typeAnnotationName [ n' ] }
609 repAnnProv ModuleAnnProvenance
610 = rep2 moduleAnnotationName []
611
612 -------------------------------------------------------
613 -- Constructors
614 -------------------------------------------------------
615
616 repC :: [Name] -> LConDecl Name -> DsM [Core TH.ConQ]
617 repC _ (L _ (ConDecl { con_names = con, con_qvars = con_tvs, con_cxt = L _ []
618 , con_details = details, con_res = ResTyH98 }))
619 | null (hsQTvBndrs con_tvs)
620 = do { con1 <- mapM lookupLOcc con -- See Note [Binders and occurrences]
621 ; mapM (\c -> repConstr c details) con1 }
622
623 repC tvs (L _ (ConDecl { con_names = cons
624 , con_qvars = con_tvs, con_cxt = L _ ctxt
625 , con_details = details
626 , con_res = res_ty }))
627 = do { (eq_ctxt, con_tv_subst) <- mkGadtCtxt tvs res_ty
628 ; let ex_tvs = HsQTvs { hsq_kvs = filterOut (in_subst con_tv_subst) (hsq_kvs con_tvs)
629 , hsq_tvs = filterOut (in_subst con_tv_subst . hsLTyVarName) (hsq_tvs con_tvs) }
630
631 ; binds <- mapM dupBinder con_tv_subst
632 ; b <- dsExtendMetaEnv (mkNameEnv binds) $ -- Binds some of the con_tvs
633 addTyVarBinds ex_tvs $ \ ex_bndrs -> -- Binds the remaining con_tvs
634 do { cons1 <- mapM lookupLOcc cons -- See Note [Binders and occurrences]
635 ; c' <- mapM (\c -> repConstr c details) cons1
636 ; ctxt' <- repContext (eq_ctxt ++ ctxt)
637 ; rep2 forallCName ([unC ex_bndrs, unC ctxt'] ++ (map unC c')) }
638 ; return [b]
639 }
640
641 in_subst :: [(Name,Name)] -> Name -> Bool
642 in_subst [] _ = False
643 in_subst ((n',_):ns) n = n==n' || in_subst ns n
644
645 mkGadtCtxt :: [Name] -- Tyvars of the data type
646 -> ResType (LHsType Name)
647 -> DsM (HsContext Name, [(Name,Name)])
648 -- Given a data type in GADT syntax, figure out the equality
649 -- context, so that we can represent it with an explicit
650 -- equality context, because that is the only way to express
651 -- the GADT in TH syntax
652 --
653 -- Example:
654 -- data T a b c where { MkT :: forall d e. d -> e -> T d [e] e
655 -- mkGadtCtxt [a,b,c] [d,e] (T d [e] e)
656 -- returns
657 -- (b~[e], c~e), [d->a]
658 --
659 -- This function is fiddly, but not really hard
660 mkGadtCtxt _ ResTyH98
661 = return ([], [])
662 mkGadtCtxt data_tvs (ResTyGADT _ res_ty)
663 | Just (_, tys) <- hsTyGetAppHead_maybe res_ty
664 , data_tvs `equalLength` tys
665 = return (go [] [] (data_tvs `zip` tys))
666
667 | otherwise
668 = failWithDs (ptext (sLit "Malformed constructor result type:") <+> ppr res_ty)
669 where
670 go cxt subst [] = (cxt, subst)
671 go cxt subst ((data_tv, ty) : rest)
672 | Just con_tv <- is_hs_tyvar ty
673 , isTyVarName con_tv
674 , not (in_subst subst con_tv)
675 = go cxt ((con_tv, data_tv) : subst) rest
676 | otherwise
677 = go (eq_pred : cxt) subst rest
678 where
679 loc = getLoc ty
680 eq_pred = L loc (HsEqTy (L loc (HsTyVar data_tv)) ty)
681
682 is_hs_tyvar (L _ (HsTyVar n)) = Just n -- Type variables *and* tycons
683 is_hs_tyvar (L _ (HsParTy ty)) = is_hs_tyvar ty
684 is_hs_tyvar _ = Nothing
685
686
687 repBangTy :: LBangType Name -> DsM (Core (TH.StrictTypeQ))
688 repBangTy ty = do
689 MkC s <- rep2 str []
690 MkC t <- repLTy ty'
691 rep2 strictTypeName [s, t]
692 where
693 (str, ty') = case ty of
694 L _ (HsBangTy (HsSrcBang _ SrcUnpack SrcStrict) ty)
695 -> (unpackedName, ty)
696 L _ (HsBangTy (HsSrcBang _ _ SrcStrict) ty)
697 -> (isStrictName, ty)
698 _ -> (notStrictName, ty)
699
700 -------------------------------------------------------
701 -- Deriving clause
702 -------------------------------------------------------
703
704 repDerivs :: Maybe (Located [LHsType Name]) -> DsM (Core [TH.Name])
705 repDerivs Nothing = coreList nameTyConName []
706 repDerivs (Just (L _ ctxt))
707 = repList nameTyConName rep_deriv ctxt
708 where
709 rep_deriv :: LHsType Name -> DsM (Core TH.Name)
710 -- Deriving clauses must have the simple H98 form
711 rep_deriv ty
712 | Just (cls, []) <- splitHsClassTy_maybe (unLoc ty)
713 = lookupOcc cls
714 | otherwise
715 = notHandled "Non-H98 deriving clause" (ppr ty)
716
717
718 -------------------------------------------------------
719 -- Signatures in a class decl, or a group of bindings
720 -------------------------------------------------------
721
722 rep_sigs :: [LSig Name] -> DsM [Core TH.DecQ]
723 rep_sigs sigs = do locs_cores <- rep_sigs' sigs
724 return $ de_loc $ sort_by_loc locs_cores
725
726 rep_sigs' :: [LSig Name] -> DsM [(SrcSpan, Core TH.DecQ)]
727 -- We silently ignore ones we don't recognise
728 rep_sigs' sigs = do { sigs1 <- mapM rep_sig sigs ;
729 return (concat sigs1) }
730
731 rep_sig :: LSig Name -> DsM [(SrcSpan, Core TH.DecQ)]
732 rep_sig (L loc (TypeSig nms ty _)) = mapM (rep_ty_sig sigDName loc ty) nms
733 rep_sig (L _ (PatSynSig {})) = notHandled "Pattern type signatures" empty
734 rep_sig (L loc (GenericSig nms ty)) = mapM (rep_ty_sig defaultSigDName loc ty) nms
735 rep_sig d@(L _ (IdSig {})) = pprPanic "rep_sig IdSig" (ppr d)
736 rep_sig (L _ (FixSig {})) = return [] -- fixity sigs at top level
737 rep_sig (L loc (InlineSig nm ispec)) = rep_inline nm ispec loc
738 rep_sig (L loc (SpecSig nm tys ispec))
739 = concatMapM (\t -> rep_specialise nm t ispec loc) tys
740 rep_sig (L loc (SpecInstSig _ ty)) = rep_specialiseInst ty loc
741 rep_sig (L _ (MinimalSig {})) = notHandled "MINIMAL pragmas" empty
742
743 rep_ty_sig :: Name -> SrcSpan -> LHsType Name -> Located Name
744 -> DsM (SrcSpan, Core TH.DecQ)
745 rep_ty_sig mk_sig loc (L _ ty) nm
746 = do { nm1 <- lookupLOcc nm
747 ; ty1 <- rep_ty ty
748 ; sig <- repProto mk_sig nm1 ty1
749 ; return (loc, sig) }
750 where
751 -- We must special-case the top-level explicit for-all of a TypeSig
752 -- See Note [Scoped type variables in bindings]
753 rep_ty (HsForAllTy Explicit _ tvs ctxt ty)
754 = do { let rep_in_scope_tv tv = do { name <- lookupBinder (hsLTyVarName tv)
755 ; repTyVarBndrWithKind tv name }
756 ; bndrs1 <- repList tyVarBndrTyConName rep_in_scope_tv (hsQTvBndrs tvs)
757 ; ctxt1 <- repLContext ctxt
758 ; ty1 <- repLTy ty
759 ; repTForall bndrs1 ctxt1 ty1 }
760
761 rep_ty ty = repTy ty
762
763 rep_inline :: Located Name
764 -> InlinePragma -- Never defaultInlinePragma
765 -> SrcSpan
766 -> DsM [(SrcSpan, Core TH.DecQ)]
767 rep_inline nm ispec loc
768 = do { nm1 <- lookupLOcc nm
769 ; inline <- repInline $ inl_inline ispec
770 ; rm <- repRuleMatch $ inl_rule ispec
771 ; phases <- repPhases $ inl_act ispec
772 ; pragma <- repPragInl nm1 inline rm phases
773 ; return [(loc, pragma)]
774 }
775
776 rep_specialise :: Located Name -> LHsType Name -> InlinePragma -> SrcSpan
777 -> DsM [(SrcSpan, Core TH.DecQ)]
778 rep_specialise nm ty ispec loc
779 = do { nm1 <- lookupLOcc nm
780 ; ty1 <- repLTy ty
781 ; phases <- repPhases $ inl_act ispec
782 ; let inline = inl_inline ispec
783 ; pragma <- if isEmptyInlineSpec inline
784 then -- SPECIALISE
785 repPragSpec nm1 ty1 phases
786 else -- SPECIALISE INLINE
787 do { inline1 <- repInline inline
788 ; repPragSpecInl nm1 ty1 inline1 phases }
789 ; return [(loc, pragma)]
790 }
791
792 rep_specialiseInst :: LHsType Name -> SrcSpan -> DsM [(SrcSpan, Core TH.DecQ)]
793 rep_specialiseInst ty loc
794 = do { ty1 <- repLTy ty
795 ; pragma <- repPragSpecInst ty1
796 ; return [(loc, pragma)] }
797
798 repInline :: InlineSpec -> DsM (Core TH.Inline)
799 repInline NoInline = dataCon noInlineDataConName
800 repInline Inline = dataCon inlineDataConName
801 repInline Inlinable = dataCon inlinableDataConName
802 repInline spec = notHandled "repInline" (ppr spec)
803
804 repRuleMatch :: RuleMatchInfo -> DsM (Core TH.RuleMatch)
805 repRuleMatch ConLike = dataCon conLikeDataConName
806 repRuleMatch FunLike = dataCon funLikeDataConName
807
808 repPhases :: Activation -> DsM (Core TH.Phases)
809 repPhases (ActiveBefore i) = do { MkC arg <- coreIntLit i
810 ; dataCon' beforePhaseDataConName [arg] }
811 repPhases (ActiveAfter i) = do { MkC arg <- coreIntLit i
812 ; dataCon' fromPhaseDataConName [arg] }
813 repPhases _ = dataCon allPhasesDataConName
814
815 -------------------------------------------------------
816 -- Types
817 -------------------------------------------------------
818
819 addTyVarBinds :: LHsTyVarBndrs Name -- the binders to be added
820 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a))) -- action in the ext env
821 -> DsM (Core (TH.Q a))
822 -- gensym a list of type variables and enter them into the meta environment;
823 -- the computations passed as the second argument is executed in that extended
824 -- meta environment and gets the *new* names on Core-level as an argument
825
826 addTyVarBinds (HsQTvs { hsq_kvs = kvs, hsq_tvs = tvs }) m
827 = do { fresh_kv_names <- mkGenSyms kvs
828 ; fresh_tv_names <- mkGenSyms (map hsLTyVarName tvs)
829 ; let fresh_names = fresh_kv_names ++ fresh_tv_names
830 ; term <- addBinds fresh_names $
831 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr (tvs `zip` fresh_tv_names)
832 ; m kbs }
833 ; wrapGenSyms fresh_names term }
834 where
835 mk_tv_bndr (tv, (_,v)) = repTyVarBndrWithKind tv (coreVar v)
836
837 addTyClTyVarBinds :: LHsTyVarBndrs Name
838 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a)))
839 -> DsM (Core (TH.Q a))
840
841 -- Used for data/newtype declarations, and family instances,
842 -- so that the nested type variables work right
843 -- instance C (T a) where
844 -- type W (T a) = blah
845 -- The 'a' in the type instance is the one bound by the instance decl
846 addTyClTyVarBinds tvs m
847 = do { let tv_names = hsLKiTyVarNames tvs
848 ; env <- dsGetMetaEnv
849 ; freshNames <- mkGenSyms (filterOut (`elemNameEnv` env) tv_names)
850 -- Make fresh names for the ones that are not already in scope
851 -- This makes things work for family declarations
852
853 ; term <- addBinds freshNames $
854 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr (hsQTvBndrs tvs)
855 ; m kbs }
856
857 ; wrapGenSyms freshNames term }
858 where
859 mk_tv_bndr tv = do { v <- lookupBinder (hsLTyVarName tv)
860 ; repTyVarBndrWithKind tv v }
861
862 -- Produce kinded binder constructors from the Haskell tyvar binders
863 --
864 repTyVarBndrWithKind :: LHsTyVarBndr Name
865 -> Core TH.Name -> DsM (Core TH.TyVarBndr)
866 repTyVarBndrWithKind (L _ (UserTyVar _)) nm
867 = repPlainTV nm
868 repTyVarBndrWithKind (L _ (KindedTyVar _ ki)) nm
869 = repLKind ki >>= repKindedTV nm
870
871 -- | Represent a type variable binder
872 repTyVarBndr :: LHsTyVarBndr Name -> DsM (Core TH.TyVarBndr)
873 repTyVarBndr (L _ (UserTyVar nm)) = do { nm' <- lookupBinder nm
874 ; repPlainTV nm' }
875 repTyVarBndr (L _ (KindedTyVar (L _ nm) ki)) = do { nm' <- lookupBinder nm
876 ; ki' <- repLKind ki
877 ; repKindedTV nm' ki' }
878
879 -- represent a type context
880 --
881 repLContext :: LHsContext Name -> DsM (Core TH.CxtQ)
882 repLContext (L _ ctxt) = repContext ctxt
883
884 repContext :: HsContext Name -> DsM (Core TH.CxtQ)
885 repContext ctxt = do preds <- repList typeQTyConName repLTy ctxt
886 repCtxt preds
887
888 -- yield the representation of a list of types
889 --
890 repLTys :: [LHsType Name] -> DsM [Core TH.TypeQ]
891 repLTys tys = mapM repLTy tys
892
893 -- represent a type
894 --
895 repLTy :: LHsType Name -> DsM (Core TH.TypeQ)
896 repLTy (L _ ty) = repTy ty
897
898 repTy :: HsType Name -> DsM (Core TH.TypeQ)
899 repTy (HsForAllTy _ extra tvs ctxt ty) =
900 addTyVarBinds tvs $ \bndrs -> do
901 ctxt1 <- repLContext ctxt'
902 ty1 <- repLTy ty
903 repTForall bndrs ctxt1 ty1
904 where
905 -- If extra is not Nothing, an extra-constraints wild card was removed
906 -- (just) before renaming. It must be put back now, otherwise the
907 -- represented type won't include this extra-constraints wild card.
908 ctxt'
909 | Just loc <- extra
910 = let uniq = panic "addExtraCtsWC"
911 -- This unique will be discarded by repLContext, but is required
912 -- to make a Name
913 name = mkInternalName uniq (mkTyVarOcc "_") loc
914 in (++ [L loc (HsWildCardTy (AnonWildCard name))]) `fmap` ctxt
915 | otherwise
916 = ctxt
917
918
919
920 repTy (HsTyVar n)
921 | isTvOcc occ = do tv1 <- lookupOcc n
922 repTvar tv1
923 | isDataOcc occ = do tc1 <- lookupOcc n
924 repPromotedTyCon tc1
925 | otherwise = do tc1 <- lookupOcc n
926 repNamedTyCon tc1
927 where
928 occ = nameOccName n
929
930 repTy (HsAppTy f a) = do
931 f1 <- repLTy f
932 a1 <- repLTy a
933 repTapp f1 a1
934 repTy (HsFunTy f a) = do
935 f1 <- repLTy f
936 a1 <- repLTy a
937 tcon <- repArrowTyCon
938 repTapps tcon [f1, a1]
939 repTy (HsListTy t) = do
940 t1 <- repLTy t
941 tcon <- repListTyCon
942 repTapp tcon t1
943 repTy (HsPArrTy t) = do
944 t1 <- repLTy t
945 tcon <- repTy (HsTyVar (tyConName parrTyCon))
946 repTapp tcon t1
947 repTy (HsTupleTy HsUnboxedTuple tys) = do
948 tys1 <- repLTys tys
949 tcon <- repUnboxedTupleTyCon (length tys)
950 repTapps tcon tys1
951 repTy (HsTupleTy _ tys) = do tys1 <- repLTys tys
952 tcon <- repTupleTyCon (length tys)
953 repTapps tcon tys1
954 repTy (HsOpTy ty1 (_, n) ty2) = repLTy ((nlHsTyVar (unLoc n) `nlHsAppTy` ty1)
955 `nlHsAppTy` ty2)
956 repTy (HsParTy t) = repLTy t
957 repTy (HsEqTy t1 t2) = do
958 t1' <- repLTy t1
959 t2' <- repLTy t2
960 eq <- repTequality
961 repTapps eq [t1', t2']
962 repTy (HsKindSig t k) = do
963 t1 <- repLTy t
964 k1 <- repLKind k
965 repTSig t1 k1
966 repTy (HsSpliceTy splice _) = repSplice splice
967 repTy (HsExplicitListTy _ tys) = do
968 tys1 <- repLTys tys
969 repTPromotedList tys1
970 repTy (HsExplicitTupleTy _ tys) = do
971 tys1 <- repLTys tys
972 tcon <- repPromotedTupleTyCon (length tys)
973 repTapps tcon tys1
974 repTy (HsTyLit lit) = do
975 lit' <- repTyLit lit
976 repTLit lit'
977 repTy (HsWildCardTy (AnonWildCard _)) = repTWildCard
978 repTy (HsWildCardTy (NamedWildCard n)) = do
979 nwc <- lookupOcc n
980 repTNamedWildCard nwc
981
982 repTy ty = notHandled "Exotic form of type" (ppr ty)
983
984 repTyLit :: HsTyLit -> DsM (Core TH.TyLitQ)
985 repTyLit (HsNumTy _ i) = do iExpr <- mkIntegerExpr i
986 rep2 numTyLitName [iExpr]
987 repTyLit (HsStrTy _ s) = do { s' <- mkStringExprFS s
988 ; rep2 strTyLitName [s']
989 }
990
991 -- represent a kind
992 --
993 repLKind :: LHsKind Name -> DsM (Core TH.Kind)
994 repLKind ki
995 = do { let (kis, ki') = splitHsFunType ki
996 ; kis_rep <- mapM repLKind kis
997 ; ki'_rep <- repNonArrowLKind ki'
998 ; kcon <- repKArrow
999 ; let f k1 k2 = repKApp kcon k1 >>= flip repKApp k2
1000 ; foldrM f ki'_rep kis_rep
1001 }
1002
1003 repNonArrowLKind :: LHsKind Name -> DsM (Core TH.Kind)
1004 repNonArrowLKind (L _ ki) = repNonArrowKind ki
1005
1006 repNonArrowKind :: HsKind Name -> DsM (Core TH.Kind)
1007 repNonArrowKind (HsTyVar name)
1008 | name == liftedTypeKindTyConName = repKStar
1009 | name == constraintKindTyConName = repKConstraint
1010 | isTvOcc (nameOccName name) = lookupOcc name >>= repKVar
1011 | otherwise = lookupOcc name >>= repKCon
1012 repNonArrowKind (HsAppTy f a) = do { f' <- repLKind f
1013 ; a' <- repLKind a
1014 ; repKApp f' a'
1015 }
1016 repNonArrowKind (HsListTy k) = do { k' <- repLKind k
1017 ; kcon <- repKList
1018 ; repKApp kcon k'
1019 }
1020 repNonArrowKind (HsTupleTy _ ks) = do { ks' <- mapM repLKind ks
1021 ; kcon <- repKTuple (length ks)
1022 ; repKApps kcon ks'
1023 }
1024 repNonArrowKind k = notHandled "Exotic form of kind" (ppr k)
1025
1026 repRole :: Located (Maybe Role) -> DsM (Core TH.Role)
1027 repRole (L _ (Just Nominal)) = rep2 nominalRName []
1028 repRole (L _ (Just Representational)) = rep2 representationalRName []
1029 repRole (L _ (Just Phantom)) = rep2 phantomRName []
1030 repRole (L _ Nothing) = rep2 inferRName []
1031
1032 -----------------------------------------------------------------------------
1033 -- Splices
1034 -----------------------------------------------------------------------------
1035
1036 repSplice :: HsSplice Name -> DsM (Core a)
1037 -- See Note [How brackets and nested splices are handled] in TcSplice
1038 -- We return a CoreExpr of any old type; the context should know
1039 repSplice (HsTypedSplice n _) = rep_splice n
1040 repSplice (HsUntypedSplice n _) = rep_splice n
1041 repSplice (HsQuasiQuote n _ _ _) = rep_splice n
1042
1043 rep_splice :: Name -> DsM (Core a)
1044 rep_splice splice_name
1045 = do { mb_val <- dsLookupMetaEnv splice_name
1046 ; case mb_val of
1047 Just (DsSplice e) -> do { e' <- dsExpr e
1048 ; return (MkC e') }
1049 _ -> pprPanic "HsSplice" (ppr splice_name) }
1050 -- Should not happen; statically checked
1051
1052 -----------------------------------------------------------------------------
1053 -- Expressions
1054 -----------------------------------------------------------------------------
1055
1056 repLEs :: [LHsExpr Name] -> DsM (Core [TH.ExpQ])
1057 repLEs es = repList expQTyConName repLE es
1058
1059 -- FIXME: some of these panics should be converted into proper error messages
1060 -- unless we can make sure that constructs, which are plainly not
1061 -- supported in TH already lead to error messages at an earlier stage
1062 repLE :: LHsExpr Name -> DsM (Core TH.ExpQ)
1063 repLE (L loc e) = putSrcSpanDs loc (repE e)
1064
1065 repE :: HsExpr Name -> DsM (Core TH.ExpQ)
1066 repE (HsVar x) =
1067 do { mb_val <- dsLookupMetaEnv x
1068 ; case mb_val of
1069 Nothing -> do { str <- globalVar x
1070 ; repVarOrCon x str }
1071 Just (DsBound y) -> repVarOrCon x (coreVar y)
1072 Just (DsSplice e) -> do { e' <- dsExpr e
1073 ; return (MkC e') } }
1074 repE e@(HsIPVar _) = notHandled "Implicit parameters" (ppr e)
1075
1076 -- Remember, we're desugaring renamer output here, so
1077 -- HsOverlit can definitely occur
1078 repE (HsOverLit l) = do { a <- repOverloadedLiteral l; repLit a }
1079 repE (HsLit l) = do { a <- repLiteral l; repLit a }
1080 repE (HsLam (MG { mg_alts = [m] })) = repLambda m
1081 repE (HsLamCase _ (MG { mg_alts = ms }))
1082 = do { ms' <- mapM repMatchTup ms
1083 ; core_ms <- coreList matchQTyConName ms'
1084 ; repLamCase core_ms }
1085 repE (HsApp x y) = do {a <- repLE x; b <- repLE y; repApp a b}
1086
1087 repE (OpApp e1 op _ e2) =
1088 do { arg1 <- repLE e1;
1089 arg2 <- repLE e2;
1090 the_op <- repLE op ;
1091 repInfixApp arg1 the_op arg2 }
1092 repE (NegApp x _) = do
1093 a <- repLE x
1094 negateVar <- lookupOcc negateName >>= repVar
1095 negateVar `repApp` a
1096 repE (HsPar x) = repLE x
1097 repE (SectionL x y) = do { a <- repLE x; b <- repLE y; repSectionL a b }
1098 repE (SectionR x y) = do { a <- repLE x; b <- repLE y; repSectionR a b }
1099 repE (HsCase e (MG { mg_alts = ms }))
1100 = do { arg <- repLE e
1101 ; ms2 <- mapM repMatchTup ms
1102 ; core_ms2 <- coreList matchQTyConName ms2
1103 ; repCaseE arg core_ms2 }
1104 repE (HsIf _ x y z) = do
1105 a <- repLE x
1106 b <- repLE y
1107 c <- repLE z
1108 repCond a b c
1109 repE (HsMultiIf _ alts)
1110 = do { (binds, alts') <- liftM unzip $ mapM repLGRHS alts
1111 ; expr' <- repMultiIf (nonEmptyCoreList alts')
1112 ; wrapGenSyms (concat binds) expr' }
1113 repE (HsLet bs e) = do { (ss,ds) <- repBinds bs
1114 ; e2 <- addBinds ss (repLE e)
1115 ; z <- repLetE ds e2
1116 ; wrapGenSyms ss z }
1117
1118 -- FIXME: I haven't got the types here right yet
1119 repE e@(HsDo ctxt sts _)
1120 | case ctxt of { DoExpr -> True; GhciStmtCtxt -> True; _ -> False }
1121 = do { (ss,zs) <- repLSts sts;
1122 e' <- repDoE (nonEmptyCoreList zs);
1123 wrapGenSyms ss e' }
1124
1125 | ListComp <- ctxt
1126 = do { (ss,zs) <- repLSts sts;
1127 e' <- repComp (nonEmptyCoreList zs);
1128 wrapGenSyms ss e' }
1129
1130 | otherwise
1131 = notHandled "mdo, monad comprehension and [: :]" (ppr e)
1132
1133 repE (ExplicitList _ _ es) = do { xs <- repLEs es; repListExp xs }
1134 repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
1135 repE e@(ExplicitTuple es boxed)
1136 | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
1137 | isBoxed boxed = do { xs <- repLEs [e | L _ (Present e) <- es]; repTup xs }
1138 | otherwise = do { xs <- repLEs [e | L _ (Present e) <- es]
1139 ; repUnboxedTup xs }
1140
1141 repE (RecordCon c _ flds)
1142 = do { x <- lookupLOcc c;
1143 fs <- repFields flds;
1144 repRecCon x fs }
1145 repE (RecordUpd e flds _ _ _)
1146 = do { x <- repLE e;
1147 fs <- repUpdFields flds;
1148 repRecUpd x fs }
1149
1150 repE (ExprWithTySig e ty _) = do { e1 <- repLE e; t1 <- repLTy ty; repSigExp e1 t1 }
1151 repE (ArithSeq _ _ aseq) =
1152 case aseq of
1153 From e -> do { ds1 <- repLE e; repFrom ds1 }
1154 FromThen e1 e2 -> do
1155 ds1 <- repLE e1
1156 ds2 <- repLE e2
1157 repFromThen ds1 ds2
1158 FromTo e1 e2 -> do
1159 ds1 <- repLE e1
1160 ds2 <- repLE e2
1161 repFromTo ds1 ds2
1162 FromThenTo e1 e2 e3 -> do
1163 ds1 <- repLE e1
1164 ds2 <- repLE e2
1165 ds3 <- repLE e3
1166 repFromThenTo ds1 ds2 ds3
1167
1168 repE (HsSpliceE splice) = repSplice splice
1169 repE (HsStatic e) = repLE e >>= rep2 staticEName . (:[]) . unC
1170 repE e@(PArrSeq {}) = notHandled "Parallel arrays" (ppr e)
1171 repE e@(HsCoreAnn {}) = notHandled "Core annotations" (ppr e)
1172 repE e@(HsSCC {}) = notHandled "Cost centres" (ppr e)
1173 repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
1174 repE e@(HsTcBracketOut {}) = notHandled "TH brackets" (ppr e)
1175 repE e = notHandled "Expression form" (ppr e)
1176
1177 -----------------------------------------------------------------------------
1178 -- Building representations of auxillary structures like Match, Clause, Stmt,
1179
1180 repMatchTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.MatchQ)
1181 repMatchTup (L _ (Match _ [p] _ (GRHSs guards wheres))) =
1182 do { ss1 <- mkGenSyms (collectPatBinders p)
1183 ; addBinds ss1 $ do {
1184 ; p1 <- repLP p
1185 ; (ss2,ds) <- repBinds wheres
1186 ; addBinds ss2 $ do {
1187 ; gs <- repGuards guards
1188 ; match <- repMatch p1 gs ds
1189 ; wrapGenSyms (ss1++ss2) match }}}
1190 repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
1191
1192 repClauseTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ClauseQ)
1193 repClauseTup (L _ (Match _ ps _ (GRHSs guards wheres))) =
1194 do { ss1 <- mkGenSyms (collectPatsBinders ps)
1195 ; addBinds ss1 $ do {
1196 ps1 <- repLPs ps
1197 ; (ss2,ds) <- repBinds wheres
1198 ; addBinds ss2 $ do {
1199 gs <- repGuards guards
1200 ; clause <- repClause ps1 gs ds
1201 ; wrapGenSyms (ss1++ss2) clause }}}
1202
1203 repGuards :: [LGRHS Name (LHsExpr Name)] -> DsM (Core TH.BodyQ)
1204 repGuards [L _ (GRHS [] e)]
1205 = do {a <- repLE e; repNormal a }
1206 repGuards other
1207 = do { zs <- mapM repLGRHS other
1208 ; let (xs, ys) = unzip zs
1209 ; gd <- repGuarded (nonEmptyCoreList ys)
1210 ; wrapGenSyms (concat xs) gd }
1211
1212 repLGRHS :: LGRHS Name (LHsExpr Name) -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
1213 repLGRHS (L _ (GRHS [L _ (BodyStmt e1 _ _ _)] e2))
1214 = do { guarded <- repLNormalGE e1 e2
1215 ; return ([], guarded) }
1216 repLGRHS (L _ (GRHS ss rhs))
1217 = do { (gs, ss') <- repLSts ss
1218 ; rhs' <- addBinds gs $ repLE rhs
1219 ; guarded <- repPatGE (nonEmptyCoreList ss') rhs'
1220 ; return (gs, guarded) }
1221
1222 repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
1223 repFields (HsRecFields { rec_flds = flds })
1224 = repList fieldExpQTyConName rep_fld flds
1225 where
1226 rep_fld :: LHsRecField Name (LHsExpr Name) -> DsM (Core (TH.Q TH.FieldExp))
1227 rep_fld (L _ fld) = do { fn <- lookupLOcc (hsRecFieldSel fld)
1228 ; e <- repLE (hsRecFieldArg fld)
1229 ; repFieldExp fn e }
1230
1231 repUpdFields :: [LHsRecUpdField Name] -> DsM (Core [TH.Q TH.FieldExp])
1232 repUpdFields = repList fieldExpQTyConName rep_fld
1233 where
1234 rep_fld :: LHsRecUpdField Name -> DsM (Core (TH.Q TH.FieldExp))
1235 rep_fld (L l fld) = case unLoc (hsRecFieldLbl fld) of
1236 Unambiguous _ sel_name -> do { fn <- lookupLOcc (L l sel_name)
1237 ; e <- repLE (hsRecFieldArg fld)
1238 ; repFieldExp fn e }
1239 _ -> notHandled "ambiguous record updates" (ppr fld)
1240
1241
1242
1243 -----------------------------------------------------------------------------
1244 -- Representing Stmt's is tricky, especially if bound variables
1245 -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |]
1246 -- First gensym new names for every variable in any of the patterns.
1247 -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
1248 -- if variables didn't shaddow, the static gensym wouldn't be necessary
1249 -- and we could reuse the original names (x and x).
1250 --
1251 -- do { x'1 <- gensym "x"
1252 -- ; x'2 <- gensym "x"
1253 -- ; doE [ BindSt (pvar x'1) [| f 1 |]
1254 -- , BindSt (pvar x'2) [| f x |]
1255 -- , NoBindSt [| g x |]
1256 -- ]
1257 -- }
1258
1259 -- The strategy is to translate a whole list of do-bindings by building a
1260 -- bigger environment, and a bigger set of meta bindings
1261 -- (like: x'1 <- gensym "x" ) and then combining these with the translations
1262 -- of the expressions within the Do
1263
1264 -----------------------------------------------------------------------------
1265 -- The helper function repSts computes the translation of each sub expression
1266 -- and a bunch of prefix bindings denoting the dynamic renaming.
1267
1268 repLSts :: [LStmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1269 repLSts stmts = repSts (map unLoc stmts)
1270
1271 repSts :: [Stmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1272 repSts (BindStmt p e _ _ : ss) =
1273 do { e2 <- repLE e
1274 ; ss1 <- mkGenSyms (collectPatBinders p)
1275 ; addBinds ss1 $ do {
1276 ; p1 <- repLP p;
1277 ; (ss2,zs) <- repSts ss
1278 ; z <- repBindSt p1 e2
1279 ; return (ss1++ss2, z : zs) }}
1280 repSts (LetStmt bs : ss) =
1281 do { (ss1,ds) <- repBinds bs
1282 ; z <- repLetSt ds
1283 ; (ss2,zs) <- addBinds ss1 (repSts ss)
1284 ; return (ss1++ss2, z : zs) }
1285 repSts (BodyStmt e _ _ _ : ss) =
1286 do { e2 <- repLE e
1287 ; z <- repNoBindSt e2
1288 ; (ss2,zs) <- repSts ss
1289 ; return (ss2, z : zs) }
1290 repSts (ParStmt stmt_blocks _ _ : ss) =
1291 do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks
1292 ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1
1293 ss1 = concat ss_s
1294 ; z <- repParSt stmt_blocks2
1295 ; (ss2, zs) <- addBinds ss1 (repSts ss)
1296 ; return (ss1++ss2, z : zs) }
1297 where
1298 rep_stmt_block :: ParStmtBlock Name Name -> DsM ([GenSymBind], Core [TH.StmtQ])
1299 rep_stmt_block (ParStmtBlock stmts _ _) =
1300 do { (ss1, zs) <- repSts (map unLoc stmts)
1301 ; zs1 <- coreList stmtQTyConName zs
1302 ; return (ss1, zs1) }
1303 repSts [LastStmt e _ _]
1304 = do { e2 <- repLE e
1305 ; z <- repNoBindSt e2
1306 ; return ([], [z]) }
1307 repSts [] = return ([],[])
1308 repSts other = notHandled "Exotic statement" (ppr other)
1309
1310
1311 -----------------------------------------------------------
1312 -- Bindings
1313 -----------------------------------------------------------
1314
1315 repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ])
1316 repBinds EmptyLocalBinds
1317 = do { core_list <- coreList decQTyConName []
1318 ; return ([], core_list) }
1319
1320 repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
1321
1322 repBinds (HsValBinds decs)
1323 = do { let { bndrs = hsSigTvBinders decs ++ collectHsValBinders decs }
1324 -- No need to worrry about detailed scopes within
1325 -- the binding group, because we are talking Names
1326 -- here, so we can safely treat it as a mutually
1327 -- recursive group
1328 -- For hsSigTvBinders see Note [Scoped type variables in bindings]
1329 ; ss <- mkGenSyms bndrs
1330 ; prs <- addBinds ss (rep_val_binds decs)
1331 ; core_list <- coreList decQTyConName
1332 (de_loc (sort_by_loc prs))
1333 ; return (ss, core_list) }
1334
1335 rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1336 -- Assumes: all the binders of the binding are alrady in the meta-env
1337 rep_val_binds (ValBindsOut binds sigs)
1338 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
1339 ; core2 <- rep_sigs' sigs
1340 ; return (core1 ++ core2) }
1341 rep_val_binds (ValBindsIn _ _)
1342 = panic "rep_val_binds: ValBindsIn"
1343
1344 rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
1345 rep_binds binds = do { binds_w_locs <- rep_binds' binds
1346 ; return (de_loc (sort_by_loc binds_w_locs)) }
1347
1348 rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1349 rep_binds' = mapM rep_bind . bagToList
1350
1351 rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
1352 -- Assumes: all the binders of the binding are alrady in the meta-env
1353
1354 -- Note GHC treats declarations of a variable (not a pattern)
1355 -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match
1356 -- with an empty list of patterns
1357 rep_bind (L loc (FunBind
1358 { fun_id = fn,
1359 fun_matches = MG { mg_alts = [L _ (Match _ [] _
1360 (GRHSs guards wheres))] } }))
1361 = do { (ss,wherecore) <- repBinds wheres
1362 ; guardcore <- addBinds ss (repGuards guards)
1363 ; fn' <- lookupLBinder fn
1364 ; p <- repPvar fn'
1365 ; ans <- repVal p guardcore wherecore
1366 ; ans' <- wrapGenSyms ss ans
1367 ; return (loc, ans') }
1368
1369 rep_bind (L loc (FunBind { fun_id = fn, fun_matches = MG { mg_alts = ms } }))
1370 = do { ms1 <- mapM repClauseTup ms
1371 ; fn' <- lookupLBinder fn
1372 ; ans <- repFun fn' (nonEmptyCoreList ms1)
1373 ; return (loc, ans) }
1374
1375 rep_bind (L loc (PatBind { pat_lhs = pat, pat_rhs = GRHSs guards wheres }))
1376 = do { patcore <- repLP pat
1377 ; (ss,wherecore) <- repBinds wheres
1378 ; guardcore <- addBinds ss (repGuards guards)
1379 ; ans <- repVal patcore guardcore wherecore
1380 ; ans' <- wrapGenSyms ss ans
1381 ; return (loc, ans') }
1382
1383 rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1384 = do { v' <- lookupBinder v
1385 ; e2 <- repLE e
1386 ; x <- repNormal e2
1387 ; patcore <- repPvar v'
1388 ; empty_decls <- coreList decQTyConName []
1389 ; ans <- repVal patcore x empty_decls
1390 ; return (srcLocSpan (getSrcLoc v), ans) }
1391
1392 rep_bind (L _ (AbsBinds {})) = panic "rep_bind: AbsBinds"
1393 rep_bind (L _ dec@(PatSynBind {})) = notHandled "pattern synonyms" (ppr dec)
1394 -----------------------------------------------------------------------------
1395 -- Since everything in a Bind is mutually recursive we need rename all
1396 -- all the variables simultaneously. For example:
1397 -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to
1398 -- do { f'1 <- gensym "f"
1399 -- ; g'2 <- gensym "g"
1400 -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]},
1401 -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]}
1402 -- ]}
1403 -- This requires collecting the bindings (f'1 <- gensym "f"), and the
1404 -- environment ( f |-> f'1 ) from each binding, and then unioning them
1405 -- together. As we do this we collect GenSymBinds's which represent the renamed
1406 -- variables bound by the Bindings. In order not to lose track of these
1407 -- representations we build a shadow datatype MB with the same structure as
1408 -- MonoBinds, but which has slots for the representations
1409
1410
1411 -----------------------------------------------------------------------------
1412 -- GHC allows a more general form of lambda abstraction than specified
1413 -- by Haskell 98. In particular it allows guarded lambda's like :
1414 -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in
1415 -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like
1416 -- (\ p1 .. pn -> exp) by causing an error.
1417
1418 repLambda :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ExpQ)
1419 repLambda (L _ (Match _ ps _ (GRHSs [L _ (GRHS [] e)] EmptyLocalBinds)))
1420 = do { let bndrs = collectPatsBinders ps ;
1421 ; ss <- mkGenSyms bndrs
1422 ; lam <- addBinds ss (
1423 do { xs <- repLPs ps; body <- repLE e; repLam xs body })
1424 ; wrapGenSyms ss lam }
1425
1426 repLambda (L _ m) = notHandled "Guarded labmdas" (pprMatch (LambdaExpr :: HsMatchContext Name) m)
1427
1428
1429 -----------------------------------------------------------------------------
1430 -- Patterns
1431 -- repP deals with patterns. It assumes that we have already
1432 -- walked over the pattern(s) once to collect the binders, and
1433 -- have extended the environment. So every pattern-bound
1434 -- variable should already appear in the environment.
1435
1436 -- Process a list of patterns
1437 repLPs :: [LPat Name] -> DsM (Core [TH.PatQ])
1438 repLPs ps = repList patQTyConName repLP ps
1439
1440 repLP :: LPat Name -> DsM (Core TH.PatQ)
1441 repLP (L _ p) = repP p
1442
1443 repP :: Pat Name -> DsM (Core TH.PatQ)
1444 repP (WildPat _) = repPwild
1445 repP (LitPat l) = do { l2 <- repLiteral l; repPlit l2 }
1446 repP (VarPat x) = do { x' <- lookupBinder x; repPvar x' }
1447 repP (LazyPat p) = do { p1 <- repLP p; repPtilde p1 }
1448 repP (BangPat p) = do { p1 <- repLP p; repPbang p1 }
1449 repP (AsPat x p) = do { x' <- lookupLBinder x; p1 <- repLP p; repPaspat x' p1 }
1450 repP (ParPat p) = repLP p
1451 repP (ListPat ps _ Nothing) = do { qs <- repLPs ps; repPlist qs }
1452 repP (ListPat ps ty1 (Just (_,e))) = do { p <- repP (ListPat ps ty1 Nothing); e' <- repE e; repPview e' p}
1453 repP (TuplePat ps boxed _)
1454 | isBoxed boxed = do { qs <- repLPs ps; repPtup qs }
1455 | otherwise = do { qs <- repLPs ps; repPunboxedTup qs }
1456 repP (ConPatIn dc details)
1457 = do { con_str <- lookupLOcc dc
1458 ; case details of
1459 PrefixCon ps -> do { qs <- repLPs ps; repPcon con_str qs }
1460 RecCon rec -> do { fps <- repList fieldPatQTyConName rep_fld (rec_flds rec)
1461 ; repPrec con_str fps }
1462 InfixCon p1 p2 -> do { p1' <- repLP p1;
1463 p2' <- repLP p2;
1464 repPinfix p1' con_str p2' }
1465 }
1466 where
1467 rep_fld :: LHsRecField Name (LPat Name) -> DsM (Core (TH.Name,TH.PatQ))
1468 rep_fld (L _ fld) = do { MkC v <- lookupLOcc (hsRecFieldSel fld)
1469 ; MkC p <- repLP (hsRecFieldArg fld)
1470 ; rep2 fieldPatName [v,p] }
1471
1472 repP (NPat (L _ l) Nothing _) = do { a <- repOverloadedLiteral l; repPlit a }
1473 repP (ViewPat e p _) = do { e' <- repLE e; p' <- repLP p; repPview e' p' }
1474 repP p@(NPat _ (Just _) _) = notHandled "Negative overloaded patterns" (ppr p)
1475 repP p@(SigPatIn {}) = notHandled "Type signatures in patterns" (ppr p)
1476 -- The problem is to do with scoped type variables.
1477 -- To implement them, we have to implement the scoping rules
1478 -- here in DsMeta, and I don't want to do that today!
1479 -- do { p' <- repLP p; t' <- repLTy t; repPsig p' t' }
1480 -- repPsig :: Core TH.PatQ -> Core TH.TypeQ -> DsM (Core TH.PatQ)
1481 -- repPsig (MkC p) (MkC t) = rep2 sigPName [p, t]
1482
1483 repP (SplicePat splice) = repSplice splice
1484
1485 repP other = notHandled "Exotic pattern" (ppr other)
1486
1487 ----------------------------------------------------------
1488 -- Declaration ordering helpers
1489
1490 sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)]
1491 sort_by_loc xs = sortBy comp xs
1492 where comp x y = compare (fst x) (fst y)
1493
1494 de_loc :: [(a, b)] -> [b]
1495 de_loc = map snd
1496
1497 ----------------------------------------------------------
1498 -- The meta-environment
1499
1500 -- A name/identifier association for fresh names of locally bound entities
1501 type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id
1502 -- I.e. (x, x_id) means
1503 -- let x_id = gensym "x" in ...
1504
1505 -- Generate a fresh name for a locally bound entity
1506
1507 mkGenSyms :: [Name] -> DsM [GenSymBind]
1508 -- We can use the existing name. For example:
1509 -- [| \x_77 -> x_77 + x_77 |]
1510 -- desugars to
1511 -- do { x_77 <- genSym "x"; .... }
1512 -- We use the same x_77 in the desugared program, but with the type Bndr
1513 -- instead of Int
1514 --
1515 -- We do make it an Internal name, though (hence localiseName)
1516 --
1517 -- Nevertheless, it's monadic because we have to generate nameTy
1518 mkGenSyms ns = do { var_ty <- lookupType nameTyConName
1519 ; return [(nm, mkLocalId (localiseName nm) var_ty) | nm <- ns] }
1520
1521
1522 addBinds :: [GenSymBind] -> DsM a -> DsM a
1523 -- Add a list of fresh names for locally bound entities to the
1524 -- meta environment (which is part of the state carried around
1525 -- by the desugarer monad)
1526 addBinds bs m = dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs]) m
1527
1528 dupBinder :: (Name, Name) -> DsM (Name, DsMetaVal)
1529 dupBinder (new, old)
1530 = do { mb_val <- dsLookupMetaEnv old
1531 ; case mb_val of
1532 Just val -> return (new, val)
1533 Nothing -> pprPanic "dupBinder" (ppr old) }
1534
1535 -- Look up a locally bound name
1536 --
1537 lookupLBinder :: Located Name -> DsM (Core TH.Name)
1538 lookupLBinder (L _ n) = lookupBinder n
1539
1540 lookupBinder :: Name -> DsM (Core TH.Name)
1541 lookupBinder = lookupOcc
1542 -- Binders are brought into scope before the pattern or what-not is
1543 -- desugared. Moreover, in instance declaration the binder of a method
1544 -- will be the selector Id and hence a global; so we need the
1545 -- globalVar case of lookupOcc
1546
1547 -- Look up a name that is either locally bound or a global name
1548 --
1549 -- * If it is a global name, generate the "original name" representation (ie,
1550 -- the <module>:<name> form) for the associated entity
1551 --
1552 lookupLOcc :: Located Name -> DsM (Core TH.Name)
1553 -- Lookup an occurrence; it can't be a splice.
1554 -- Use the in-scope bindings if they exist
1555 lookupLOcc (L _ n) = lookupOcc n
1556
1557 lookupOcc :: Name -> DsM (Core TH.Name)
1558 lookupOcc n
1559 = do { mb_val <- dsLookupMetaEnv n ;
1560 case mb_val of
1561 Nothing -> globalVar n
1562 Just (DsBound x) -> return (coreVar x)
1563 Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n)
1564 }
1565
1566 globalVar :: Name -> DsM (Core TH.Name)
1567 -- Not bound by the meta-env
1568 -- Could be top-level; or could be local
1569 -- f x = $(g [| x |])
1570 -- Here the x will be local
1571 globalVar name
1572 | isExternalName name
1573 = do { MkC mod <- coreStringLit name_mod
1574 ; MkC pkg <- coreStringLit name_pkg
1575 ; MkC occ <- occNameLit name
1576 ; rep2 mk_varg [pkg,mod,occ] }
1577 | otherwise
1578 = do { MkC occ <- occNameLit name
1579 ; MkC uni <- coreIntLit (getKey (getUnique name))
1580 ; rep2 mkNameLName [occ,uni] }
1581 where
1582 mod = ASSERT( isExternalName name) nameModule name
1583 name_mod = moduleNameString (moduleName mod)
1584 name_pkg = unitIdString (moduleUnitId mod)
1585 name_occ = nameOccName name
1586 mk_varg | OccName.isDataOcc name_occ = mkNameG_dName
1587 | OccName.isVarOcc name_occ = mkNameG_vName
1588 | OccName.isTcOcc name_occ = mkNameG_tcName
1589 | otherwise = pprPanic "DsMeta.globalVar" (ppr name)
1590
1591 lookupType :: Name -- Name of type constructor (e.g. TH.ExpQ)
1592 -> DsM Type -- The type
1593 lookupType tc_name = do { tc <- dsLookupTyCon tc_name ;
1594 return (mkTyConApp tc []) }
1595
1596 wrapGenSyms :: [GenSymBind]
1597 -> Core (TH.Q a) -> DsM (Core (TH.Q a))
1598 -- wrapGenSyms [(nm1,id1), (nm2,id2)] y
1599 -- --> bindQ (gensym nm1) (\ id1 ->
1600 -- bindQ (gensym nm2 (\ id2 ->
1601 -- y))
1602
1603 wrapGenSyms binds body@(MkC b)
1604 = do { var_ty <- lookupType nameTyConName
1605 ; go var_ty binds }
1606 where
1607 [elt_ty] = tcTyConAppArgs (exprType b)
1608 -- b :: Q a, so we can get the type 'a' by looking at the
1609 -- argument type. NB: this relies on Q being a data/newtype,
1610 -- not a type synonym
1611
1612 go _ [] = return body
1613 go var_ty ((name,id) : binds)
1614 = do { MkC body' <- go var_ty binds
1615 ; lit_str <- occNameLit name
1616 ; gensym_app <- repGensym lit_str
1617 ; repBindQ var_ty elt_ty
1618 gensym_app (MkC (Lam id body')) }
1619
1620 occNameLit :: Name -> DsM (Core String)
1621 occNameLit n = coreStringLit (occNameString (nameOccName n))
1622
1623
1624 -- %*********************************************************************
1625 -- %* *
1626 -- Constructing code
1627 -- %* *
1628 -- %*********************************************************************
1629
1630 -----------------------------------------------------------------------------
1631 -- PHANTOM TYPES for consistency. In order to make sure we do this correct
1632 -- we invent a new datatype which uses phantom types.
1633
1634 newtype Core a = MkC CoreExpr
1635 unC :: Core a -> CoreExpr
1636 unC (MkC x) = x
1637
1638 rep2 :: Name -> [ CoreExpr ] -> DsM (Core a)
1639 rep2 n xs = do { id <- dsLookupGlobalId n
1640 ; return (MkC (foldl App (Var id) xs)) }
1641
1642 dataCon' :: Name -> [CoreExpr] -> DsM (Core a)
1643 dataCon' n args = do { id <- dsLookupDataCon n
1644 ; return $ MkC $ mkCoreConApps id args }
1645
1646 dataCon :: Name -> DsM (Core a)
1647 dataCon n = dataCon' n []
1648
1649 -- Then we make "repConstructors" which use the phantom types for each of the
1650 -- smart constructors of the Meta.Meta datatypes.
1651
1652
1653 -- %*********************************************************************
1654 -- %* *
1655 -- The 'smart constructors'
1656 -- %* *
1657 -- %*********************************************************************
1658
1659 --------------- Patterns -----------------
1660 repPlit :: Core TH.Lit -> DsM (Core TH.PatQ)
1661 repPlit (MkC l) = rep2 litPName [l]
1662
1663 repPvar :: Core TH.Name -> DsM (Core TH.PatQ)
1664 repPvar (MkC s) = rep2 varPName [s]
1665
1666 repPtup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1667 repPtup (MkC ps) = rep2 tupPName [ps]
1668
1669 repPunboxedTup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1670 repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps]
1671
1672 repPcon :: Core TH.Name -> Core [TH.PatQ] -> DsM (Core TH.PatQ)
1673 repPcon (MkC s) (MkC ps) = rep2 conPName [s, ps]
1674
1675 repPrec :: Core TH.Name -> Core [(TH.Name,TH.PatQ)] -> DsM (Core TH.PatQ)
1676 repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps]
1677
1678 repPinfix :: Core TH.PatQ -> Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1679 repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2]
1680
1681 repPtilde :: Core TH.PatQ -> DsM (Core TH.PatQ)
1682 repPtilde (MkC p) = rep2 tildePName [p]
1683
1684 repPbang :: Core TH.PatQ -> DsM (Core TH.PatQ)
1685 repPbang (MkC p) = rep2 bangPName [p]
1686
1687 repPaspat :: Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1688 repPaspat (MkC s) (MkC p) = rep2 asPName [s, p]
1689
1690 repPwild :: DsM (Core TH.PatQ)
1691 repPwild = rep2 wildPName []
1692
1693 repPlist :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1694 repPlist (MkC ps) = rep2 listPName [ps]
1695
1696 repPview :: Core TH.ExpQ -> Core TH.PatQ -> DsM (Core TH.PatQ)
1697 repPview (MkC e) (MkC p) = rep2 viewPName [e,p]
1698
1699 --------------- Expressions -----------------
1700 repVarOrCon :: Name -> Core TH.Name -> DsM (Core TH.ExpQ)
1701 repVarOrCon vc str | isDataOcc (nameOccName vc) = repCon str
1702 | otherwise = repVar str
1703
1704 repVar :: Core TH.Name -> DsM (Core TH.ExpQ)
1705 repVar (MkC s) = rep2 varEName [s]
1706
1707 repCon :: Core TH.Name -> DsM (Core TH.ExpQ)
1708 repCon (MkC s) = rep2 conEName [s]
1709
1710 repLit :: Core TH.Lit -> DsM (Core TH.ExpQ)
1711 repLit (MkC c) = rep2 litEName [c]
1712
1713 repApp :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1714 repApp (MkC x) (MkC y) = rep2 appEName [x,y]
1715
1716 repLam :: Core [TH.PatQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1717 repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e]
1718
1719 repLamCase :: Core [TH.MatchQ] -> DsM (Core TH.ExpQ)
1720 repLamCase (MkC ms) = rep2 lamCaseEName [ms]
1721
1722 repTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1723 repTup (MkC es) = rep2 tupEName [es]
1724
1725 repUnboxedTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1726 repUnboxedTup (MkC es) = rep2 unboxedTupEName [es]
1727
1728 repCond :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1729 repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z]
1730
1731 repMultiIf :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.ExpQ)
1732 repMultiIf (MkC alts) = rep2 multiIfEName [alts]
1733
1734 repLetE :: Core [TH.DecQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1735 repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e]
1736
1737 repCaseE :: Core TH.ExpQ -> Core [TH.MatchQ] -> DsM( Core TH.ExpQ)
1738 repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms]
1739
1740 repDoE :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1741 repDoE (MkC ss) = rep2 doEName [ss]
1742
1743 repComp :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1744 repComp (MkC ss) = rep2 compEName [ss]
1745
1746 repListExp :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1747 repListExp (MkC es) = rep2 listEName [es]
1748
1749 repSigExp :: Core TH.ExpQ -> Core TH.TypeQ -> DsM (Core TH.ExpQ)
1750 repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t]
1751
1752 repRecCon :: Core TH.Name -> Core [TH.Q TH.FieldExp]-> DsM (Core TH.ExpQ)
1753 repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs]
1754
1755 repRecUpd :: Core TH.ExpQ -> Core [TH.Q TH.FieldExp] -> DsM (Core TH.ExpQ)
1756 repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs]
1757
1758 repFieldExp :: Core TH.Name -> Core TH.ExpQ -> DsM (Core (TH.Q TH.FieldExp))
1759 repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x]
1760
1761 repInfixApp :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1762 repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z]
1763
1764 repSectionL :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1765 repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y]
1766
1767 repSectionR :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1768 repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y]
1769
1770 ------------ Right hand sides (guarded expressions) ----
1771 repGuarded :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.BodyQ)
1772 repGuarded (MkC pairs) = rep2 guardedBName [pairs]
1773
1774 repNormal :: Core TH.ExpQ -> DsM (Core TH.BodyQ)
1775 repNormal (MkC e) = rep2 normalBName [e]
1776
1777 ------------ Guards ----
1778 repLNormalGE :: LHsExpr Name -> LHsExpr Name -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1779 repLNormalGE g e = do g' <- repLE g
1780 e' <- repLE e
1781 repNormalGE g' e'
1782
1783 repNormalGE :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1784 repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e]
1785
1786 repPatGE :: Core [TH.StmtQ] -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1787 repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e]
1788
1789 ------------- Stmts -------------------
1790 repBindSt :: Core TH.PatQ -> Core TH.ExpQ -> DsM (Core TH.StmtQ)
1791 repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e]
1792
1793 repLetSt :: Core [TH.DecQ] -> DsM (Core TH.StmtQ)
1794 repLetSt (MkC ds) = rep2 letSName [ds]
1795
1796 repNoBindSt :: Core TH.ExpQ -> DsM (Core TH.StmtQ)
1797 repNoBindSt (MkC e) = rep2 noBindSName [e]
1798
1799 repParSt :: Core [[TH.StmtQ]] -> DsM (Core TH.StmtQ)
1800 repParSt (MkC sss) = rep2 parSName [sss]
1801
1802 -------------- Range (Arithmetic sequences) -----------
1803 repFrom :: Core TH.ExpQ -> DsM (Core TH.ExpQ)
1804 repFrom (MkC x) = rep2 fromEName [x]
1805
1806 repFromThen :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1807 repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y]
1808
1809 repFromTo :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1810 repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y]
1811
1812 repFromThenTo :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1813 repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z]
1814
1815 ------------ Match and Clause Tuples -----------
1816 repMatch :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.MatchQ)
1817 repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds]
1818
1819 repClause :: Core [TH.PatQ] -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.ClauseQ)
1820 repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds]
1821
1822 -------------- Dec -----------------------------
1823 repVal :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1824 repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds]
1825
1826 repFun :: Core TH.Name -> Core [TH.ClauseQ] -> DsM (Core TH.DecQ)
1827 repFun (MkC nm) (MkC b) = rep2 funDName [nm, b]
1828
1829 repData :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1830 -> Maybe (Core [TH.TypeQ])
1831 -> Core [TH.ConQ] -> Core [TH.Name] -> DsM (Core TH.DecQ)
1832 repData (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC cons) (MkC derivs)
1833 = rep2 dataDName [cxt, nm, tvs, cons, derivs]
1834 repData (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC cons) (MkC derivs)
1835 = rep2 dataInstDName [cxt, nm, tys, cons, derivs]
1836
1837 repNewtype :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1838 -> Maybe (Core [TH.TypeQ])
1839 -> Core TH.ConQ -> Core [TH.Name] -> DsM (Core TH.DecQ)
1840 repNewtype (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC con) (MkC derivs)
1841 = rep2 newtypeDName [cxt, nm, tvs, con, derivs]
1842 repNewtype (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC con) (MkC derivs)
1843 = rep2 newtypeInstDName [cxt, nm, tys, con, derivs]
1844
1845 repTySyn :: Core TH.Name -> Core [TH.TyVarBndr]
1846 -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1847 repTySyn (MkC nm) (MkC tvs) (MkC rhs)
1848 = rep2 tySynDName [nm, tvs, rhs]
1849
1850 repInst :: Core TH.CxtQ -> Core TH.TypeQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1851 repInst (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceDName [cxt, ty, ds]
1852
1853 repClass :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1854 -> Core [TH.FunDep] -> Core [TH.DecQ]
1855 -> DsM (Core TH.DecQ)
1856 repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds)
1857 = rep2 classDName [cxt, cls, tvs, fds, ds]
1858
1859 repDeriv :: Core TH.CxtQ -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1860 repDeriv (MkC cxt) (MkC ty) = rep2 standaloneDerivDName [cxt, ty]
1861
1862 repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch
1863 -> Core TH.Phases -> DsM (Core TH.DecQ)
1864 repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases)
1865 = rep2 pragInlDName [nm, inline, rm, phases]
1866
1867 repPragSpec :: Core TH.Name -> Core TH.TypeQ -> Core TH.Phases
1868 -> DsM (Core TH.DecQ)
1869 repPragSpec (MkC nm) (MkC ty) (MkC phases)
1870 = rep2 pragSpecDName [nm, ty, phases]
1871
1872 repPragSpecInl :: Core TH.Name -> Core TH.TypeQ -> Core TH.Inline
1873 -> Core TH.Phases -> DsM (Core TH.DecQ)
1874 repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases)
1875 = rep2 pragSpecInlDName [nm, ty, inline, phases]
1876
1877 repPragSpecInst :: Core TH.TypeQ -> DsM (Core TH.DecQ)
1878 repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty]
1879
1880 repPragRule :: Core String -> Core [TH.RuleBndrQ] -> Core TH.ExpQ
1881 -> Core TH.ExpQ -> Core TH.Phases -> DsM (Core TH.DecQ)
1882 repPragRule (MkC nm) (MkC bndrs) (MkC lhs) (MkC rhs) (MkC phases)
1883 = rep2 pragRuleDName [nm, bndrs, lhs, rhs, phases]
1884
1885 repPragAnn :: Core TH.AnnTarget -> Core TH.ExpQ -> DsM (Core TH.DecQ)
1886 repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e]
1887
1888 repTySynInst :: Core TH.Name -> Core TH.TySynEqnQ -> DsM (Core TH.DecQ)
1889 repTySynInst (MkC nm) (MkC eqn)
1890 = rep2 tySynInstDName [nm, eqn]
1891
1892 repDataFamilyD :: Core TH.Name -> Core [TH.TyVarBndr]
1893 -> Core (Maybe TH.Kind) -> DsM (Core TH.DecQ)
1894 repDataFamilyD (MkC nm) (MkC tvs) (MkC kind)
1895 = rep2 dataFamilyDName [nm, tvs, kind]
1896
1897 repOpenFamilyD :: Core TH.Name
1898 -> Core [TH.TyVarBndr]
1899 -> Core TH.FamilyResultSig
1900 -> Core (Maybe TH.InjectivityAnn)
1901 -> DsM (Core TH.DecQ)
1902 repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj)
1903 = rep2 openTypeFamilyDName [nm, tvs, result, inj]
1904
1905 repClosedFamilyD :: Core TH.Name
1906 -> Core [TH.TyVarBndr]
1907 -> Core TH.FamilyResultSig
1908 -> Core (Maybe TH.InjectivityAnn)
1909 -> Core [TH.TySynEqnQ]
1910 -> DsM (Core TH.DecQ)
1911 repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns)
1912 = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns]
1913
1914 repTySynEqn :: Core [TH.TypeQ] -> Core TH.TypeQ -> DsM (Core TH.TySynEqnQ)
1915 repTySynEqn (MkC lhs) (MkC rhs)
1916 = rep2 tySynEqnName [lhs, rhs]
1917
1918 repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> DsM (Core TH.DecQ)
1919 repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles]
1920
1921 repFunDep :: Core [TH.Name] -> Core [TH.Name] -> DsM (Core TH.FunDep)
1922 repFunDep (MkC xs) (MkC ys) = rep2 funDepName [xs, ys]
1923
1924 repProto :: Name -> Core TH.Name -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1925 repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty]
1926
1927 repCtxt :: Core [TH.PredQ] -> DsM (Core TH.CxtQ)
1928 repCtxt (MkC tys) = rep2 cxtName [tys]
1929
1930 repConstr :: Core TH.Name -> HsConDeclDetails Name
1931 -> DsM (Core TH.ConQ)
1932 repConstr con (PrefixCon ps)
1933 = do arg_tys <- repList strictTypeQTyConName repBangTy ps
1934 rep2 normalCName [unC con, unC arg_tys]
1935
1936 repConstr con (RecCon (L _ ips))
1937 = do { args <- concatMapM rep_ip ips
1938 ; arg_vtys <- coreList varStrictTypeQTyConName args
1939 ; rep2 recCName [unC con, unC arg_vtys] }
1940 where
1941 rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip)
1942
1943 rep_one_ip :: LBangType Name -> LFieldOcc Name -> DsM (Core a)
1944 rep_one_ip t n = do { MkC v <- lookupOcc (selectorFieldOcc $ unLoc n)
1945 ; MkC ty <- repBangTy t
1946 ; rep2 varStrictTypeName [v,ty] }
1947
1948 repConstr con (InfixCon st1 st2)
1949 = do arg1 <- repBangTy st1
1950 arg2 <- repBangTy st2
1951 rep2 infixCName [unC arg1, unC con, unC arg2]
1952
1953 ------------ Types -------------------
1954
1955 repTForall :: Core [TH.TyVarBndr] -> Core TH.CxtQ -> Core TH.TypeQ
1956 -> DsM (Core TH.TypeQ)
1957 repTForall (MkC tvars) (MkC ctxt) (MkC ty)
1958 = rep2 forallTName [tvars, ctxt, ty]
1959
1960 repTvar :: Core TH.Name -> DsM (Core TH.TypeQ)
1961 repTvar (MkC s) = rep2 varTName [s]
1962
1963 repTapp :: Core TH.TypeQ -> Core TH.TypeQ -> DsM (Core TH.TypeQ)
1964 repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2]
1965
1966 repTapps :: Core TH.TypeQ -> [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
1967 repTapps f [] = return f
1968 repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts }
1969
1970 repTSig :: Core TH.TypeQ -> Core TH.Kind -> DsM (Core TH.TypeQ)
1971 repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki]
1972
1973 repTequality :: DsM (Core TH.TypeQ)
1974 repTequality = rep2 equalityTName []
1975
1976 repTPromotedList :: [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
1977 repTPromotedList [] = repPromotedNilTyCon
1978 repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon
1979 ; f <- repTapp tcon t
1980 ; t' <- repTPromotedList ts
1981 ; repTapp f t'
1982 }
1983
1984 repTLit :: Core TH.TyLitQ -> DsM (Core TH.TypeQ)
1985 repTLit (MkC lit) = rep2 litTName [lit]
1986
1987 repTWildCard :: DsM (Core TH.TypeQ)
1988 repTWildCard = rep2 wildCardTName []
1989
1990 repTNamedWildCard :: Core TH.Name -> DsM (Core TH.TypeQ)
1991 repTNamedWildCard (MkC s) = rep2 namedWildCardTName [s]
1992
1993
1994 --------- Type constructors --------------
1995
1996 repNamedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
1997 repNamedTyCon (MkC s) = rep2 conTName [s]
1998
1999 repTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2000 -- Note: not Core Int; it's easier to be direct here
2001 repTupleTyCon i = do dflags <- getDynFlags
2002 rep2 tupleTName [mkIntExprInt dflags i]
2003
2004 repUnboxedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2005 -- Note: not Core Int; it's easier to be direct here
2006 repUnboxedTupleTyCon i = do dflags <- getDynFlags
2007 rep2 unboxedTupleTName [mkIntExprInt dflags i]
2008
2009 repArrowTyCon :: DsM (Core TH.TypeQ)
2010 repArrowTyCon = rep2 arrowTName []
2011
2012 repListTyCon :: DsM (Core TH.TypeQ)
2013 repListTyCon = rep2 listTName []
2014
2015 repPromotedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2016 repPromotedTyCon (MkC s) = rep2 promotedTName [s]
2017
2018 repPromotedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2019 repPromotedTupleTyCon i = do dflags <- getDynFlags
2020 rep2 promotedTupleTName [mkIntExprInt dflags i]
2021
2022 repPromotedNilTyCon :: DsM (Core TH.TypeQ)
2023 repPromotedNilTyCon = rep2 promotedNilTName []
2024
2025 repPromotedConsTyCon :: DsM (Core TH.TypeQ)
2026 repPromotedConsTyCon = rep2 promotedConsTName []
2027
2028 ------------ Kinds -------------------
2029
2030 repPlainTV :: Core TH.Name -> DsM (Core TH.TyVarBndr)
2031 repPlainTV (MkC nm) = rep2 plainTVName [nm]
2032
2033 repKindedTV :: Core TH.Name -> Core TH.Kind -> DsM (Core TH.TyVarBndr)
2034 repKindedTV (MkC nm) (MkC ki) = rep2 kindedTVName [nm, ki]
2035
2036 repKVar :: Core TH.Name -> DsM (Core TH.Kind)
2037 repKVar (MkC s) = rep2 varKName [s]
2038
2039 repKCon :: Core TH.Name -> DsM (Core TH.Kind)
2040 repKCon (MkC s) = rep2 conKName [s]
2041
2042 repKTuple :: Int -> DsM (Core TH.Kind)
2043 repKTuple i = do dflags <- getDynFlags
2044 rep2 tupleKName [mkIntExprInt dflags i]
2045
2046 repKArrow :: DsM (Core TH.Kind)
2047 repKArrow = rep2 arrowKName []
2048
2049 repKList :: DsM (Core TH.Kind)
2050 repKList = rep2 listKName []
2051
2052 repKApp :: Core TH.Kind -> Core TH.Kind -> DsM (Core TH.Kind)
2053 repKApp (MkC k1) (MkC k2) = rep2 appKName [k1, k2]
2054
2055 repKApps :: Core TH.Kind -> [Core TH.Kind] -> DsM (Core TH.Kind)
2056 repKApps f [] = return f
2057 repKApps f (k:ks) = do { f' <- repKApp f k; repKApps f' ks }
2058
2059 repKStar :: DsM (Core TH.Kind)
2060 repKStar = rep2 starKName []
2061
2062 repKConstraint :: DsM (Core TH.Kind)
2063 repKConstraint = rep2 constraintKName []
2064
2065 ----------------------------------------------------------
2066 -- Type family result signature
2067
2068 repNoSig :: DsM (Core TH.FamilyResultSig)
2069 repNoSig = rep2 noSigName []
2070
2071 repKindSig :: Core TH.Kind -> DsM (Core TH.FamilyResultSig)
2072 repKindSig (MkC ki) = rep2 kindSigName [ki]
2073
2074 repTyVarSig :: Core TH.TyVarBndr -> DsM (Core TH.FamilyResultSig)
2075 repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr]
2076
2077 ----------------------------------------------------------
2078 -- Literals
2079
2080 repLiteral :: HsLit -> DsM (Core TH.Lit)
2081 repLiteral (HsStringPrim _ bs)
2082 = do dflags <- getDynFlags
2083 word8_ty <- lookupType word8TyConName
2084 let w8s = unpack bs
2085 w8s_expr = map (\w8 -> mkCoreConApps word8DataCon
2086 [mkWordLit dflags (toInteger w8)]) w8s
2087 rep2 stringPrimLName [mkListExpr word8_ty w8s_expr]
2088 repLiteral lit
2089 = do lit' <- case lit of
2090 HsIntPrim _ i -> mk_integer i
2091 HsWordPrim _ w -> mk_integer w
2092 HsInt _ i -> mk_integer i
2093 HsFloatPrim r -> mk_rational r
2094 HsDoublePrim r -> mk_rational r
2095 HsCharPrim _ c -> mk_char c
2096 _ -> return lit
2097 lit_expr <- dsLit lit'
2098 case mb_lit_name of
2099 Just lit_name -> rep2 lit_name [lit_expr]
2100 Nothing -> notHandled "Exotic literal" (ppr lit)
2101 where
2102 mb_lit_name = case lit of
2103 HsInteger _ _ _ -> Just integerLName
2104 HsInt _ _ -> Just integerLName
2105 HsIntPrim _ _ -> Just intPrimLName
2106 HsWordPrim _ _ -> Just wordPrimLName
2107 HsFloatPrim _ -> Just floatPrimLName
2108 HsDoublePrim _ -> Just doublePrimLName
2109 HsChar _ _ -> Just charLName
2110 HsCharPrim _ _ -> Just charPrimLName
2111 HsString _ _ -> Just stringLName
2112 HsRat _ _ -> Just rationalLName
2113 _ -> Nothing
2114
2115 mk_integer :: Integer -> DsM HsLit
2116 mk_integer i = do integer_ty <- lookupType integerTyConName
2117 return $ HsInteger "" i integer_ty
2118 mk_rational :: FractionalLit -> DsM HsLit
2119 mk_rational r = do rat_ty <- lookupType rationalTyConName
2120 return $ HsRat r rat_ty
2121 mk_string :: FastString -> DsM HsLit
2122 mk_string s = return $ HsString "" s
2123
2124 mk_char :: Char -> DsM HsLit
2125 mk_char c = return $ HsChar "" c
2126
2127 repOverloadedLiteral :: HsOverLit Name -> DsM (Core TH.Lit)
2128 repOverloadedLiteral (OverLit { ol_val = val})
2129 = do { lit <- mk_lit val; repLiteral lit }
2130 -- The type Rational will be in the environment, because
2131 -- the smart constructor 'TH.Syntax.rationalL' uses it in its type,
2132 -- and rationalL is sucked in when any TH stuff is used
2133
2134 mk_lit :: OverLitVal -> DsM HsLit
2135 mk_lit (HsIntegral _ i) = mk_integer i
2136 mk_lit (HsFractional f) = mk_rational f
2137 mk_lit (HsIsString _ s) = mk_string s
2138
2139 --------------- Miscellaneous -------------------
2140
2141 repGensym :: Core String -> DsM (Core (TH.Q TH.Name))
2142 repGensym (MkC lit_str) = rep2 newNameName [lit_str]
2143
2144 repBindQ :: Type -> Type -- a and b
2145 -> Core (TH.Q a) -> Core (a -> TH.Q b) -> DsM (Core (TH.Q b))
2146 repBindQ ty_a ty_b (MkC x) (MkC y)
2147 = rep2 bindQName [Type ty_a, Type ty_b, x, y]
2148
2149 repSequenceQ :: Type -> Core [TH.Q a] -> DsM (Core (TH.Q [a]))
2150 repSequenceQ ty_a (MkC list)
2151 = rep2 sequenceQName [Type ty_a, list]
2152
2153 ------------ Lists -------------------
2154 -- turn a list of patterns into a single pattern matching a list
2155
2156 repList :: Name -> (a -> DsM (Core b))
2157 -> [a] -> DsM (Core [b])
2158 repList tc_name f args
2159 = do { args1 <- mapM f args
2160 ; coreList tc_name args1 }
2161
2162 coreList :: Name -- Of the TyCon of the element type
2163 -> [Core a] -> DsM (Core [a])
2164 coreList tc_name es
2165 = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) }
2166
2167 coreList' :: Type -- The element type
2168 -> [Core a] -> Core [a]
2169 coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es ))
2170
2171 nonEmptyCoreList :: [Core a] -> Core [a]
2172 -- The list must be non-empty so we can get the element type
2173 -- Otherwise use coreList
2174 nonEmptyCoreList [] = panic "coreList: empty argument"
2175 nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs))
2176
2177 coreStringLit :: String -> DsM (Core String)
2178 coreStringLit s = do { z <- mkStringExpr s; return(MkC z) }
2179
2180 ------------------- Maybe ------------------
2181
2182 -- | Construct Core expression for Nothing of a given type name
2183 coreNothing :: Name -- ^ Name of the TyCon of the element type
2184 -> DsM (Core (Maybe a))
2185 coreNothing tc_name =
2186 do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) }
2187
2188 -- | Construct Core expression for Nothing of a given type
2189 coreNothing' :: Type -- ^ The element type
2190 -> Core (Maybe a)
2191 coreNothing' elt_ty = MkC (mkNothingExpr elt_ty)
2192
2193 -- | Store given Core expression in a Just of a given type name
2194 coreJust :: Name -- ^ Name of the TyCon of the element type
2195 -> Core a -> DsM (Core (Maybe a))
2196 coreJust tc_name es
2197 = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) }
2198
2199 -- | Store given Core expression in a Just of a given type
2200 coreJust' :: Type -- ^ The element type
2201 -> Core a -> Core (Maybe a)
2202 coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es))
2203
2204 ------------ Literals & Variables -------------------
2205
2206 coreIntLit :: Int -> DsM (Core Int)
2207 coreIntLit i = do dflags <- getDynFlags
2208 return (MkC (mkIntExprInt dflags i))
2209
2210 coreVar :: Id -> Core TH.Name -- The Id has type Name
2211 coreVar id = MkC (Var id)
2212
2213 ----------------- Failure -----------------------
2214 notHandledL :: SrcSpan -> String -> SDoc -> DsM a
2215 notHandledL loc what doc
2216 | isGoodSrcSpan loc
2217 = putSrcSpanDs loc $ notHandled what doc
2218 | otherwise
2219 = notHandled what doc
2220
2221 notHandled :: String -> SDoc -> DsM a
2222 notHandled what doc = failWithDs msg
2223 where
2224 msg = hang (text what <+> ptext (sLit "not (yet) handled by Template Haskell"))
2225 2 doc