Add typed holes support in Template Haskell.
[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 (HsUnboundVar name) = do
1171 occ <- occNameLit name
1172 sname <- repNameS occ
1173 repUnboundVar sname
1174
1175 repE e@(PArrSeq {}) = notHandled "Parallel arrays" (ppr e)
1176 repE e@(HsCoreAnn {}) = notHandled "Core annotations" (ppr e)
1177 repE e@(HsSCC {}) = notHandled "Cost centres" (ppr e)
1178 repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
1179 repE e@(HsTcBracketOut {}) = notHandled "TH brackets" (ppr e)
1180 repE e = notHandled "Expression form" (ppr e)
1181
1182 -----------------------------------------------------------------------------
1183 -- Building representations of auxillary structures like Match, Clause, Stmt,
1184
1185 repMatchTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.MatchQ)
1186 repMatchTup (L _ (Match _ [p] _ (GRHSs guards wheres))) =
1187 do { ss1 <- mkGenSyms (collectPatBinders p)
1188 ; addBinds ss1 $ do {
1189 ; p1 <- repLP p
1190 ; (ss2,ds) <- repBinds wheres
1191 ; addBinds ss2 $ do {
1192 ; gs <- repGuards guards
1193 ; match <- repMatch p1 gs ds
1194 ; wrapGenSyms (ss1++ss2) match }}}
1195 repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
1196
1197 repClauseTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ClauseQ)
1198 repClauseTup (L _ (Match _ ps _ (GRHSs guards wheres))) =
1199 do { ss1 <- mkGenSyms (collectPatsBinders ps)
1200 ; addBinds ss1 $ do {
1201 ps1 <- repLPs ps
1202 ; (ss2,ds) <- repBinds wheres
1203 ; addBinds ss2 $ do {
1204 gs <- repGuards guards
1205 ; clause <- repClause ps1 gs ds
1206 ; wrapGenSyms (ss1++ss2) clause }}}
1207
1208 repGuards :: [LGRHS Name (LHsExpr Name)] -> DsM (Core TH.BodyQ)
1209 repGuards [L _ (GRHS [] e)]
1210 = do {a <- repLE e; repNormal a }
1211 repGuards other
1212 = do { zs <- mapM repLGRHS other
1213 ; let (xs, ys) = unzip zs
1214 ; gd <- repGuarded (nonEmptyCoreList ys)
1215 ; wrapGenSyms (concat xs) gd }
1216
1217 repLGRHS :: LGRHS Name (LHsExpr Name) -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
1218 repLGRHS (L _ (GRHS [L _ (BodyStmt e1 _ _ _)] e2))
1219 = do { guarded <- repLNormalGE e1 e2
1220 ; return ([], guarded) }
1221 repLGRHS (L _ (GRHS ss rhs))
1222 = do { (gs, ss') <- repLSts ss
1223 ; rhs' <- addBinds gs $ repLE rhs
1224 ; guarded <- repPatGE (nonEmptyCoreList ss') rhs'
1225 ; return (gs, guarded) }
1226
1227 repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
1228 repFields (HsRecFields { rec_flds = flds })
1229 = repList fieldExpQTyConName rep_fld flds
1230 where
1231 rep_fld :: LHsRecField Name (LHsExpr Name) -> DsM (Core (TH.Q TH.FieldExp))
1232 rep_fld (L _ fld) = do { fn <- lookupLOcc (hsRecFieldSel fld)
1233 ; e <- repLE (hsRecFieldArg fld)
1234 ; repFieldExp fn e }
1235
1236 repUpdFields :: [LHsRecUpdField Name] -> DsM (Core [TH.Q TH.FieldExp])
1237 repUpdFields = repList fieldExpQTyConName rep_fld
1238 where
1239 rep_fld :: LHsRecUpdField Name -> DsM (Core (TH.Q TH.FieldExp))
1240 rep_fld (L l fld) = case unLoc (hsRecFieldLbl fld) of
1241 Unambiguous _ sel_name -> do { fn <- lookupLOcc (L l sel_name)
1242 ; e <- repLE (hsRecFieldArg fld)
1243 ; repFieldExp fn e }
1244 _ -> notHandled "ambiguous record updates" (ppr fld)
1245
1246
1247
1248 -----------------------------------------------------------------------------
1249 -- Representing Stmt's is tricky, especially if bound variables
1250 -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |]
1251 -- First gensym new names for every variable in any of the patterns.
1252 -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
1253 -- if variables didn't shaddow, the static gensym wouldn't be necessary
1254 -- and we could reuse the original names (x and x).
1255 --
1256 -- do { x'1 <- gensym "x"
1257 -- ; x'2 <- gensym "x"
1258 -- ; doE [ BindSt (pvar x'1) [| f 1 |]
1259 -- , BindSt (pvar x'2) [| f x |]
1260 -- , NoBindSt [| g x |]
1261 -- ]
1262 -- }
1263
1264 -- The strategy is to translate a whole list of do-bindings by building a
1265 -- bigger environment, and a bigger set of meta bindings
1266 -- (like: x'1 <- gensym "x" ) and then combining these with the translations
1267 -- of the expressions within the Do
1268
1269 -----------------------------------------------------------------------------
1270 -- The helper function repSts computes the translation of each sub expression
1271 -- and a bunch of prefix bindings denoting the dynamic renaming.
1272
1273 repLSts :: [LStmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1274 repLSts stmts = repSts (map unLoc stmts)
1275
1276 repSts :: [Stmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1277 repSts (BindStmt p e _ _ : ss) =
1278 do { e2 <- repLE e
1279 ; ss1 <- mkGenSyms (collectPatBinders p)
1280 ; addBinds ss1 $ do {
1281 ; p1 <- repLP p;
1282 ; (ss2,zs) <- repSts ss
1283 ; z <- repBindSt p1 e2
1284 ; return (ss1++ss2, z : zs) }}
1285 repSts (LetStmt bs : ss) =
1286 do { (ss1,ds) <- repBinds bs
1287 ; z <- repLetSt ds
1288 ; (ss2,zs) <- addBinds ss1 (repSts ss)
1289 ; return (ss1++ss2, z : zs) }
1290 repSts (BodyStmt e _ _ _ : ss) =
1291 do { e2 <- repLE e
1292 ; z <- repNoBindSt e2
1293 ; (ss2,zs) <- repSts ss
1294 ; return (ss2, z : zs) }
1295 repSts (ParStmt stmt_blocks _ _ : ss) =
1296 do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks
1297 ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1
1298 ss1 = concat ss_s
1299 ; z <- repParSt stmt_blocks2
1300 ; (ss2, zs) <- addBinds ss1 (repSts ss)
1301 ; return (ss1++ss2, z : zs) }
1302 where
1303 rep_stmt_block :: ParStmtBlock Name Name -> DsM ([GenSymBind], Core [TH.StmtQ])
1304 rep_stmt_block (ParStmtBlock stmts _ _) =
1305 do { (ss1, zs) <- repSts (map unLoc stmts)
1306 ; zs1 <- coreList stmtQTyConName zs
1307 ; return (ss1, zs1) }
1308 repSts [LastStmt e _ _]
1309 = do { e2 <- repLE e
1310 ; z <- repNoBindSt e2
1311 ; return ([], [z]) }
1312 repSts [] = return ([],[])
1313 repSts other = notHandled "Exotic statement" (ppr other)
1314
1315
1316 -----------------------------------------------------------
1317 -- Bindings
1318 -----------------------------------------------------------
1319
1320 repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ])
1321 repBinds EmptyLocalBinds
1322 = do { core_list <- coreList decQTyConName []
1323 ; return ([], core_list) }
1324
1325 repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
1326
1327 repBinds (HsValBinds decs)
1328 = do { let { bndrs = hsSigTvBinders decs ++ collectHsValBinders decs }
1329 -- No need to worrry about detailed scopes within
1330 -- the binding group, because we are talking Names
1331 -- here, so we can safely treat it as a mutually
1332 -- recursive group
1333 -- For hsSigTvBinders see Note [Scoped type variables in bindings]
1334 ; ss <- mkGenSyms bndrs
1335 ; prs <- addBinds ss (rep_val_binds decs)
1336 ; core_list <- coreList decQTyConName
1337 (de_loc (sort_by_loc prs))
1338 ; return (ss, core_list) }
1339
1340 rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1341 -- Assumes: all the binders of the binding are alrady in the meta-env
1342 rep_val_binds (ValBindsOut binds sigs)
1343 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
1344 ; core2 <- rep_sigs' sigs
1345 ; return (core1 ++ core2) }
1346 rep_val_binds (ValBindsIn _ _)
1347 = panic "rep_val_binds: ValBindsIn"
1348
1349 rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
1350 rep_binds binds = do { binds_w_locs <- rep_binds' binds
1351 ; return (de_loc (sort_by_loc binds_w_locs)) }
1352
1353 rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1354 rep_binds' = mapM rep_bind . bagToList
1355
1356 rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
1357 -- Assumes: all the binders of the binding are alrady in the meta-env
1358
1359 -- Note GHC treats declarations of a variable (not a pattern)
1360 -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match
1361 -- with an empty list of patterns
1362 rep_bind (L loc (FunBind
1363 { fun_id = fn,
1364 fun_matches = MG { mg_alts = [L _ (Match _ [] _
1365 (GRHSs guards wheres))] } }))
1366 = do { (ss,wherecore) <- repBinds wheres
1367 ; guardcore <- addBinds ss (repGuards guards)
1368 ; fn' <- lookupLBinder fn
1369 ; p <- repPvar fn'
1370 ; ans <- repVal p guardcore wherecore
1371 ; ans' <- wrapGenSyms ss ans
1372 ; return (loc, ans') }
1373
1374 rep_bind (L loc (FunBind { fun_id = fn, fun_matches = MG { mg_alts = ms } }))
1375 = do { ms1 <- mapM repClauseTup ms
1376 ; fn' <- lookupLBinder fn
1377 ; ans <- repFun fn' (nonEmptyCoreList ms1)
1378 ; return (loc, ans) }
1379
1380 rep_bind (L loc (PatBind { pat_lhs = pat, pat_rhs = GRHSs guards wheres }))
1381 = do { patcore <- repLP pat
1382 ; (ss,wherecore) <- repBinds wheres
1383 ; guardcore <- addBinds ss (repGuards guards)
1384 ; ans <- repVal patcore guardcore wherecore
1385 ; ans' <- wrapGenSyms ss ans
1386 ; return (loc, ans') }
1387
1388 rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1389 = do { v' <- lookupBinder v
1390 ; e2 <- repLE e
1391 ; x <- repNormal e2
1392 ; patcore <- repPvar v'
1393 ; empty_decls <- coreList decQTyConName []
1394 ; ans <- repVal patcore x empty_decls
1395 ; return (srcLocSpan (getSrcLoc v), ans) }
1396
1397 rep_bind (L _ (AbsBinds {})) = panic "rep_bind: AbsBinds"
1398 rep_bind (L _ dec@(PatSynBind {})) = notHandled "pattern synonyms" (ppr dec)
1399 -----------------------------------------------------------------------------
1400 -- Since everything in a Bind is mutually recursive we need rename all
1401 -- all the variables simultaneously. For example:
1402 -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to
1403 -- do { f'1 <- gensym "f"
1404 -- ; g'2 <- gensym "g"
1405 -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]},
1406 -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]}
1407 -- ]}
1408 -- This requires collecting the bindings (f'1 <- gensym "f"), and the
1409 -- environment ( f |-> f'1 ) from each binding, and then unioning them
1410 -- together. As we do this we collect GenSymBinds's which represent the renamed
1411 -- variables bound by the Bindings. In order not to lose track of these
1412 -- representations we build a shadow datatype MB with the same structure as
1413 -- MonoBinds, but which has slots for the representations
1414
1415
1416 -----------------------------------------------------------------------------
1417 -- GHC allows a more general form of lambda abstraction than specified
1418 -- by Haskell 98. In particular it allows guarded lambda's like :
1419 -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in
1420 -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like
1421 -- (\ p1 .. pn -> exp) by causing an error.
1422
1423 repLambda :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ExpQ)
1424 repLambda (L _ (Match _ ps _ (GRHSs [L _ (GRHS [] e)] EmptyLocalBinds)))
1425 = do { let bndrs = collectPatsBinders ps ;
1426 ; ss <- mkGenSyms bndrs
1427 ; lam <- addBinds ss (
1428 do { xs <- repLPs ps; body <- repLE e; repLam xs body })
1429 ; wrapGenSyms ss lam }
1430
1431 repLambda (L _ m) = notHandled "Guarded labmdas" (pprMatch (LambdaExpr :: HsMatchContext Name) m)
1432
1433
1434 -----------------------------------------------------------------------------
1435 -- Patterns
1436 -- repP deals with patterns. It assumes that we have already
1437 -- walked over the pattern(s) once to collect the binders, and
1438 -- have extended the environment. So every pattern-bound
1439 -- variable should already appear in the environment.
1440
1441 -- Process a list of patterns
1442 repLPs :: [LPat Name] -> DsM (Core [TH.PatQ])
1443 repLPs ps = repList patQTyConName repLP ps
1444
1445 repLP :: LPat Name -> DsM (Core TH.PatQ)
1446 repLP (L _ p) = repP p
1447
1448 repP :: Pat Name -> DsM (Core TH.PatQ)
1449 repP (WildPat _) = repPwild
1450 repP (LitPat l) = do { l2 <- repLiteral l; repPlit l2 }
1451 repP (VarPat x) = do { x' <- lookupBinder x; repPvar x' }
1452 repP (LazyPat p) = do { p1 <- repLP p; repPtilde p1 }
1453 repP (BangPat p) = do { p1 <- repLP p; repPbang p1 }
1454 repP (AsPat x p) = do { x' <- lookupLBinder x; p1 <- repLP p; repPaspat x' p1 }
1455 repP (ParPat p) = repLP p
1456 repP (ListPat ps _ Nothing) = do { qs <- repLPs ps; repPlist qs }
1457 repP (ListPat ps ty1 (Just (_,e))) = do { p <- repP (ListPat ps ty1 Nothing); e' <- repE e; repPview e' p}
1458 repP (TuplePat ps boxed _)
1459 | isBoxed boxed = do { qs <- repLPs ps; repPtup qs }
1460 | otherwise = do { qs <- repLPs ps; repPunboxedTup qs }
1461 repP (ConPatIn dc details)
1462 = do { con_str <- lookupLOcc dc
1463 ; case details of
1464 PrefixCon ps -> do { qs <- repLPs ps; repPcon con_str qs }
1465 RecCon rec -> do { fps <- repList fieldPatQTyConName rep_fld (rec_flds rec)
1466 ; repPrec con_str fps }
1467 InfixCon p1 p2 -> do { p1' <- repLP p1;
1468 p2' <- repLP p2;
1469 repPinfix p1' con_str p2' }
1470 }
1471 where
1472 rep_fld :: LHsRecField Name (LPat Name) -> DsM (Core (TH.Name,TH.PatQ))
1473 rep_fld (L _ fld) = do { MkC v <- lookupLOcc (hsRecFieldSel fld)
1474 ; MkC p <- repLP (hsRecFieldArg fld)
1475 ; rep2 fieldPatName [v,p] }
1476
1477 repP (NPat (L _ l) Nothing _) = do { a <- repOverloadedLiteral l; repPlit a }
1478 repP (ViewPat e p _) = do { e' <- repLE e; p' <- repLP p; repPview e' p' }
1479 repP p@(NPat _ (Just _) _) = notHandled "Negative overloaded patterns" (ppr p)
1480 repP p@(SigPatIn {}) = notHandled "Type signatures in patterns" (ppr p)
1481 -- The problem is to do with scoped type variables.
1482 -- To implement them, we have to implement the scoping rules
1483 -- here in DsMeta, and I don't want to do that today!
1484 -- do { p' <- repLP p; t' <- repLTy t; repPsig p' t' }
1485 -- repPsig :: Core TH.PatQ -> Core TH.TypeQ -> DsM (Core TH.PatQ)
1486 -- repPsig (MkC p) (MkC t) = rep2 sigPName [p, t]
1487
1488 repP (SplicePat splice) = repSplice splice
1489
1490 repP other = notHandled "Exotic pattern" (ppr other)
1491
1492 ----------------------------------------------------------
1493 -- Declaration ordering helpers
1494
1495 sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)]
1496 sort_by_loc xs = sortBy comp xs
1497 where comp x y = compare (fst x) (fst y)
1498
1499 de_loc :: [(a, b)] -> [b]
1500 de_loc = map snd
1501
1502 ----------------------------------------------------------
1503 -- The meta-environment
1504
1505 -- A name/identifier association for fresh names of locally bound entities
1506 type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id
1507 -- I.e. (x, x_id) means
1508 -- let x_id = gensym "x" in ...
1509
1510 -- Generate a fresh name for a locally bound entity
1511
1512 mkGenSyms :: [Name] -> DsM [GenSymBind]
1513 -- We can use the existing name. For example:
1514 -- [| \x_77 -> x_77 + x_77 |]
1515 -- desugars to
1516 -- do { x_77 <- genSym "x"; .... }
1517 -- We use the same x_77 in the desugared program, but with the type Bndr
1518 -- instead of Int
1519 --
1520 -- We do make it an Internal name, though (hence localiseName)
1521 --
1522 -- Nevertheless, it's monadic because we have to generate nameTy
1523 mkGenSyms ns = do { var_ty <- lookupType nameTyConName
1524 ; return [(nm, mkLocalId (localiseName nm) var_ty) | nm <- ns] }
1525
1526
1527 addBinds :: [GenSymBind] -> DsM a -> DsM a
1528 -- Add a list of fresh names for locally bound entities to the
1529 -- meta environment (which is part of the state carried around
1530 -- by the desugarer monad)
1531 addBinds bs m = dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs]) m
1532
1533 dupBinder :: (Name, Name) -> DsM (Name, DsMetaVal)
1534 dupBinder (new, old)
1535 = do { mb_val <- dsLookupMetaEnv old
1536 ; case mb_val of
1537 Just val -> return (new, val)
1538 Nothing -> pprPanic "dupBinder" (ppr old) }
1539
1540 -- Look up a locally bound name
1541 --
1542 lookupLBinder :: Located Name -> DsM (Core TH.Name)
1543 lookupLBinder (L _ n) = lookupBinder n
1544
1545 lookupBinder :: Name -> DsM (Core TH.Name)
1546 lookupBinder = lookupOcc
1547 -- Binders are brought into scope before the pattern or what-not is
1548 -- desugared. Moreover, in instance declaration the binder of a method
1549 -- will be the selector Id and hence a global; so we need the
1550 -- globalVar case of lookupOcc
1551
1552 -- Look up a name that is either locally bound or a global name
1553 --
1554 -- * If it is a global name, generate the "original name" representation (ie,
1555 -- the <module>:<name> form) for the associated entity
1556 --
1557 lookupLOcc :: Located Name -> DsM (Core TH.Name)
1558 -- Lookup an occurrence; it can't be a splice.
1559 -- Use the in-scope bindings if they exist
1560 lookupLOcc (L _ n) = lookupOcc n
1561
1562 lookupOcc :: Name -> DsM (Core TH.Name)
1563 lookupOcc n
1564 = do { mb_val <- dsLookupMetaEnv n ;
1565 case mb_val of
1566 Nothing -> globalVar n
1567 Just (DsBound x) -> return (coreVar x)
1568 Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n)
1569 }
1570
1571 globalVar :: Name -> DsM (Core TH.Name)
1572 -- Not bound by the meta-env
1573 -- Could be top-level; or could be local
1574 -- f x = $(g [| x |])
1575 -- Here the x will be local
1576 globalVar name
1577 | isExternalName name
1578 = do { MkC mod <- coreStringLit name_mod
1579 ; MkC pkg <- coreStringLit name_pkg
1580 ; MkC occ <- nameLit name
1581 ; rep2 mk_varg [pkg,mod,occ] }
1582 | otherwise
1583 = do { MkC occ <- nameLit name
1584 ; MkC uni <- coreIntLit (getKey (getUnique name))
1585 ; rep2 mkNameLName [occ,uni] }
1586 where
1587 mod = ASSERT( isExternalName name) nameModule name
1588 name_mod = moduleNameString (moduleName mod)
1589 name_pkg = unitIdString (moduleUnitId mod)
1590 name_occ = nameOccName name
1591 mk_varg | OccName.isDataOcc name_occ = mkNameG_dName
1592 | OccName.isVarOcc name_occ = mkNameG_vName
1593 | OccName.isTcOcc name_occ = mkNameG_tcName
1594 | otherwise = pprPanic "DsMeta.globalVar" (ppr name)
1595
1596 lookupType :: Name -- Name of type constructor (e.g. TH.ExpQ)
1597 -> DsM Type -- The type
1598 lookupType tc_name = do { tc <- dsLookupTyCon tc_name ;
1599 return (mkTyConApp tc []) }
1600
1601 wrapGenSyms :: [GenSymBind]
1602 -> Core (TH.Q a) -> DsM (Core (TH.Q a))
1603 -- wrapGenSyms [(nm1,id1), (nm2,id2)] y
1604 -- --> bindQ (gensym nm1) (\ id1 ->
1605 -- bindQ (gensym nm2 (\ id2 ->
1606 -- y))
1607
1608 wrapGenSyms binds body@(MkC b)
1609 = do { var_ty <- lookupType nameTyConName
1610 ; go var_ty binds }
1611 where
1612 [elt_ty] = tcTyConAppArgs (exprType b)
1613 -- b :: Q a, so we can get the type 'a' by looking at the
1614 -- argument type. NB: this relies on Q being a data/newtype,
1615 -- not a type synonym
1616
1617 go _ [] = return body
1618 go var_ty ((name,id) : binds)
1619 = do { MkC body' <- go var_ty binds
1620 ; lit_str <- nameLit name
1621 ; gensym_app <- repGensym lit_str
1622 ; repBindQ var_ty elt_ty
1623 gensym_app (MkC (Lam id body')) }
1624
1625 nameLit :: Name -> DsM (Core String)
1626 nameLit n = coreStringLit (occNameString (nameOccName n))
1627
1628 occNameLit :: OccName -> DsM (Core String)
1629 occNameLit name = coreStringLit (occNameString name)
1630
1631
1632 -- %*********************************************************************
1633 -- %* *
1634 -- Constructing code
1635 -- %* *
1636 -- %*********************************************************************
1637
1638 -----------------------------------------------------------------------------
1639 -- PHANTOM TYPES for consistency. In order to make sure we do this correct
1640 -- we invent a new datatype which uses phantom types.
1641
1642 newtype Core a = MkC CoreExpr
1643 unC :: Core a -> CoreExpr
1644 unC (MkC x) = x
1645
1646 rep2 :: Name -> [ CoreExpr ] -> DsM (Core a)
1647 rep2 n xs = do { id <- dsLookupGlobalId n
1648 ; return (MkC (foldl App (Var id) xs)) }
1649
1650 dataCon' :: Name -> [CoreExpr] -> DsM (Core a)
1651 dataCon' n args = do { id <- dsLookupDataCon n
1652 ; return $ MkC $ mkCoreConApps id args }
1653
1654 dataCon :: Name -> DsM (Core a)
1655 dataCon n = dataCon' n []
1656
1657 -- Then we make "repConstructors" which use the phantom types for each of the
1658 -- smart constructors of the Meta.Meta datatypes.
1659
1660
1661 -- %*********************************************************************
1662 -- %* *
1663 -- The 'smart constructors'
1664 -- %* *
1665 -- %*********************************************************************
1666
1667 --------------- Patterns -----------------
1668 repPlit :: Core TH.Lit -> DsM (Core TH.PatQ)
1669 repPlit (MkC l) = rep2 litPName [l]
1670
1671 repPvar :: Core TH.Name -> DsM (Core TH.PatQ)
1672 repPvar (MkC s) = rep2 varPName [s]
1673
1674 repPtup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1675 repPtup (MkC ps) = rep2 tupPName [ps]
1676
1677 repPunboxedTup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1678 repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps]
1679
1680 repPcon :: Core TH.Name -> Core [TH.PatQ] -> DsM (Core TH.PatQ)
1681 repPcon (MkC s) (MkC ps) = rep2 conPName [s, ps]
1682
1683 repPrec :: Core TH.Name -> Core [(TH.Name,TH.PatQ)] -> DsM (Core TH.PatQ)
1684 repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps]
1685
1686 repPinfix :: Core TH.PatQ -> Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1687 repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2]
1688
1689 repPtilde :: Core TH.PatQ -> DsM (Core TH.PatQ)
1690 repPtilde (MkC p) = rep2 tildePName [p]
1691
1692 repPbang :: Core TH.PatQ -> DsM (Core TH.PatQ)
1693 repPbang (MkC p) = rep2 bangPName [p]
1694
1695 repPaspat :: Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1696 repPaspat (MkC s) (MkC p) = rep2 asPName [s, p]
1697
1698 repPwild :: DsM (Core TH.PatQ)
1699 repPwild = rep2 wildPName []
1700
1701 repPlist :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1702 repPlist (MkC ps) = rep2 listPName [ps]
1703
1704 repPview :: Core TH.ExpQ -> Core TH.PatQ -> DsM (Core TH.PatQ)
1705 repPview (MkC e) (MkC p) = rep2 viewPName [e,p]
1706
1707 --------------- Expressions -----------------
1708 repVarOrCon :: Name -> Core TH.Name -> DsM (Core TH.ExpQ)
1709 repVarOrCon vc str | isDataOcc (nameOccName vc) = repCon str
1710 | otherwise = repVar str
1711
1712 repVar :: Core TH.Name -> DsM (Core TH.ExpQ)
1713 repVar (MkC s) = rep2 varEName [s]
1714
1715 repCon :: Core TH.Name -> DsM (Core TH.ExpQ)
1716 repCon (MkC s) = rep2 conEName [s]
1717
1718 repLit :: Core TH.Lit -> DsM (Core TH.ExpQ)
1719 repLit (MkC c) = rep2 litEName [c]
1720
1721 repApp :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1722 repApp (MkC x) (MkC y) = rep2 appEName [x,y]
1723
1724 repLam :: Core [TH.PatQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1725 repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e]
1726
1727 repLamCase :: Core [TH.MatchQ] -> DsM (Core TH.ExpQ)
1728 repLamCase (MkC ms) = rep2 lamCaseEName [ms]
1729
1730 repTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1731 repTup (MkC es) = rep2 tupEName [es]
1732
1733 repUnboxedTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1734 repUnboxedTup (MkC es) = rep2 unboxedTupEName [es]
1735
1736 repCond :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1737 repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z]
1738
1739 repMultiIf :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.ExpQ)
1740 repMultiIf (MkC alts) = rep2 multiIfEName [alts]
1741
1742 repLetE :: Core [TH.DecQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1743 repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e]
1744
1745 repCaseE :: Core TH.ExpQ -> Core [TH.MatchQ] -> DsM( Core TH.ExpQ)
1746 repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms]
1747
1748 repDoE :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1749 repDoE (MkC ss) = rep2 doEName [ss]
1750
1751 repComp :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1752 repComp (MkC ss) = rep2 compEName [ss]
1753
1754 repListExp :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1755 repListExp (MkC es) = rep2 listEName [es]
1756
1757 repSigExp :: Core TH.ExpQ -> Core TH.TypeQ -> DsM (Core TH.ExpQ)
1758 repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t]
1759
1760 repRecCon :: Core TH.Name -> Core [TH.Q TH.FieldExp]-> DsM (Core TH.ExpQ)
1761 repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs]
1762
1763 repRecUpd :: Core TH.ExpQ -> Core [TH.Q TH.FieldExp] -> DsM (Core TH.ExpQ)
1764 repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs]
1765
1766 repFieldExp :: Core TH.Name -> Core TH.ExpQ -> DsM (Core (TH.Q TH.FieldExp))
1767 repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x]
1768
1769 repInfixApp :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1770 repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z]
1771
1772 repSectionL :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1773 repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y]
1774
1775 repSectionR :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1776 repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y]
1777
1778 ------------ Right hand sides (guarded expressions) ----
1779 repGuarded :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.BodyQ)
1780 repGuarded (MkC pairs) = rep2 guardedBName [pairs]
1781
1782 repNormal :: Core TH.ExpQ -> DsM (Core TH.BodyQ)
1783 repNormal (MkC e) = rep2 normalBName [e]
1784
1785 ------------ Guards ----
1786 repLNormalGE :: LHsExpr Name -> LHsExpr Name -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1787 repLNormalGE g e = do g' <- repLE g
1788 e' <- repLE e
1789 repNormalGE g' e'
1790
1791 repNormalGE :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1792 repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e]
1793
1794 repPatGE :: Core [TH.StmtQ] -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1795 repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e]
1796
1797 ------------- Stmts -------------------
1798 repBindSt :: Core TH.PatQ -> Core TH.ExpQ -> DsM (Core TH.StmtQ)
1799 repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e]
1800
1801 repLetSt :: Core [TH.DecQ] -> DsM (Core TH.StmtQ)
1802 repLetSt (MkC ds) = rep2 letSName [ds]
1803
1804 repNoBindSt :: Core TH.ExpQ -> DsM (Core TH.StmtQ)
1805 repNoBindSt (MkC e) = rep2 noBindSName [e]
1806
1807 repParSt :: Core [[TH.StmtQ]] -> DsM (Core TH.StmtQ)
1808 repParSt (MkC sss) = rep2 parSName [sss]
1809
1810 -------------- Range (Arithmetic sequences) -----------
1811 repFrom :: Core TH.ExpQ -> DsM (Core TH.ExpQ)
1812 repFrom (MkC x) = rep2 fromEName [x]
1813
1814 repFromThen :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1815 repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y]
1816
1817 repFromTo :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1818 repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y]
1819
1820 repFromThenTo :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1821 repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z]
1822
1823 ------------ Match and Clause Tuples -----------
1824 repMatch :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.MatchQ)
1825 repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds]
1826
1827 repClause :: Core [TH.PatQ] -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.ClauseQ)
1828 repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds]
1829
1830 -------------- Dec -----------------------------
1831 repVal :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1832 repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds]
1833
1834 repFun :: Core TH.Name -> Core [TH.ClauseQ] -> DsM (Core TH.DecQ)
1835 repFun (MkC nm) (MkC b) = rep2 funDName [nm, b]
1836
1837 repData :: 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 repData (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC cons) (MkC derivs)
1841 = rep2 dataDName [cxt, nm, tvs, cons, derivs]
1842 repData (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC cons) (MkC derivs)
1843 = rep2 dataInstDName [cxt, nm, tys, cons, derivs]
1844
1845 repNewtype :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1846 -> Maybe (Core [TH.TypeQ])
1847 -> Core TH.ConQ -> Core [TH.Name] -> DsM (Core TH.DecQ)
1848 repNewtype (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC con) (MkC derivs)
1849 = rep2 newtypeDName [cxt, nm, tvs, con, derivs]
1850 repNewtype (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC con) (MkC derivs)
1851 = rep2 newtypeInstDName [cxt, nm, tys, con, derivs]
1852
1853 repTySyn :: Core TH.Name -> Core [TH.TyVarBndr]
1854 -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1855 repTySyn (MkC nm) (MkC tvs) (MkC rhs)
1856 = rep2 tySynDName [nm, tvs, rhs]
1857
1858 repInst :: Core TH.CxtQ -> Core TH.TypeQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1859 repInst (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceDName [cxt, ty, ds]
1860
1861 repClass :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1862 -> Core [TH.FunDep] -> Core [TH.DecQ]
1863 -> DsM (Core TH.DecQ)
1864 repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds)
1865 = rep2 classDName [cxt, cls, tvs, fds, ds]
1866
1867 repDeriv :: Core TH.CxtQ -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1868 repDeriv (MkC cxt) (MkC ty) = rep2 standaloneDerivDName [cxt, ty]
1869
1870 repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch
1871 -> Core TH.Phases -> DsM (Core TH.DecQ)
1872 repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases)
1873 = rep2 pragInlDName [nm, inline, rm, phases]
1874
1875 repPragSpec :: Core TH.Name -> Core TH.TypeQ -> Core TH.Phases
1876 -> DsM (Core TH.DecQ)
1877 repPragSpec (MkC nm) (MkC ty) (MkC phases)
1878 = rep2 pragSpecDName [nm, ty, phases]
1879
1880 repPragSpecInl :: Core TH.Name -> Core TH.TypeQ -> Core TH.Inline
1881 -> Core TH.Phases -> DsM (Core TH.DecQ)
1882 repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases)
1883 = rep2 pragSpecInlDName [nm, ty, inline, phases]
1884
1885 repPragSpecInst :: Core TH.TypeQ -> DsM (Core TH.DecQ)
1886 repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty]
1887
1888 repPragRule :: Core String -> Core [TH.RuleBndrQ] -> Core TH.ExpQ
1889 -> Core TH.ExpQ -> Core TH.Phases -> DsM (Core TH.DecQ)
1890 repPragRule (MkC nm) (MkC bndrs) (MkC lhs) (MkC rhs) (MkC phases)
1891 = rep2 pragRuleDName [nm, bndrs, lhs, rhs, phases]
1892
1893 repPragAnn :: Core TH.AnnTarget -> Core TH.ExpQ -> DsM (Core TH.DecQ)
1894 repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e]
1895
1896 repTySynInst :: Core TH.Name -> Core TH.TySynEqnQ -> DsM (Core TH.DecQ)
1897 repTySynInst (MkC nm) (MkC eqn)
1898 = rep2 tySynInstDName [nm, eqn]
1899
1900 repDataFamilyD :: Core TH.Name -> Core [TH.TyVarBndr]
1901 -> Core (Maybe TH.Kind) -> DsM (Core TH.DecQ)
1902 repDataFamilyD (MkC nm) (MkC tvs) (MkC kind)
1903 = rep2 dataFamilyDName [nm, tvs, kind]
1904
1905 repOpenFamilyD :: Core TH.Name
1906 -> Core [TH.TyVarBndr]
1907 -> Core TH.FamilyResultSig
1908 -> Core (Maybe TH.InjectivityAnn)
1909 -> DsM (Core TH.DecQ)
1910 repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj)
1911 = rep2 openTypeFamilyDName [nm, tvs, result, inj]
1912
1913 repClosedFamilyD :: Core TH.Name
1914 -> Core [TH.TyVarBndr]
1915 -> Core TH.FamilyResultSig
1916 -> Core (Maybe TH.InjectivityAnn)
1917 -> Core [TH.TySynEqnQ]
1918 -> DsM (Core TH.DecQ)
1919 repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns)
1920 = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns]
1921
1922 repTySynEqn :: Core [TH.TypeQ] -> Core TH.TypeQ -> DsM (Core TH.TySynEqnQ)
1923 repTySynEqn (MkC lhs) (MkC rhs)
1924 = rep2 tySynEqnName [lhs, rhs]
1925
1926 repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> DsM (Core TH.DecQ)
1927 repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles]
1928
1929 repFunDep :: Core [TH.Name] -> Core [TH.Name] -> DsM (Core TH.FunDep)
1930 repFunDep (MkC xs) (MkC ys) = rep2 funDepName [xs, ys]
1931
1932 repProto :: Name -> Core TH.Name -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1933 repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty]
1934
1935 repCtxt :: Core [TH.PredQ] -> DsM (Core TH.CxtQ)
1936 repCtxt (MkC tys) = rep2 cxtName [tys]
1937
1938 repConstr :: Core TH.Name -> HsConDeclDetails Name
1939 -> DsM (Core TH.ConQ)
1940 repConstr con (PrefixCon ps)
1941 = do arg_tys <- repList strictTypeQTyConName repBangTy ps
1942 rep2 normalCName [unC con, unC arg_tys]
1943
1944 repConstr con (RecCon (L _ ips))
1945 = do { args <- concatMapM rep_ip ips
1946 ; arg_vtys <- coreList varStrictTypeQTyConName args
1947 ; rep2 recCName [unC con, unC arg_vtys] }
1948 where
1949 rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip)
1950
1951 rep_one_ip :: LBangType Name -> LFieldOcc Name -> DsM (Core a)
1952 rep_one_ip t n = do { MkC v <- lookupOcc (selectorFieldOcc $ unLoc n)
1953 ; MkC ty <- repBangTy t
1954 ; rep2 varStrictTypeName [v,ty] }
1955
1956 repConstr con (InfixCon st1 st2)
1957 = do arg1 <- repBangTy st1
1958 arg2 <- repBangTy st2
1959 rep2 infixCName [unC arg1, unC con, unC arg2]
1960
1961 ------------ Types -------------------
1962
1963 repTForall :: Core [TH.TyVarBndr] -> Core TH.CxtQ -> Core TH.TypeQ
1964 -> DsM (Core TH.TypeQ)
1965 repTForall (MkC tvars) (MkC ctxt) (MkC ty)
1966 = rep2 forallTName [tvars, ctxt, ty]
1967
1968 repTvar :: Core TH.Name -> DsM (Core TH.TypeQ)
1969 repTvar (MkC s) = rep2 varTName [s]
1970
1971 repTapp :: Core TH.TypeQ -> Core TH.TypeQ -> DsM (Core TH.TypeQ)
1972 repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2]
1973
1974 repTapps :: Core TH.TypeQ -> [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
1975 repTapps f [] = return f
1976 repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts }
1977
1978 repTSig :: Core TH.TypeQ -> Core TH.Kind -> DsM (Core TH.TypeQ)
1979 repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki]
1980
1981 repTequality :: DsM (Core TH.TypeQ)
1982 repTequality = rep2 equalityTName []
1983
1984 repTPromotedList :: [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
1985 repTPromotedList [] = repPromotedNilTyCon
1986 repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon
1987 ; f <- repTapp tcon t
1988 ; t' <- repTPromotedList ts
1989 ; repTapp f t'
1990 }
1991
1992 repTLit :: Core TH.TyLitQ -> DsM (Core TH.TypeQ)
1993 repTLit (MkC lit) = rep2 litTName [lit]
1994
1995 repTWildCard :: DsM (Core TH.TypeQ)
1996 repTWildCard = rep2 wildCardTName []
1997
1998 repTNamedWildCard :: Core TH.Name -> DsM (Core TH.TypeQ)
1999 repTNamedWildCard (MkC s) = rep2 namedWildCardTName [s]
2000
2001
2002 --------- Type constructors --------------
2003
2004 repNamedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2005 repNamedTyCon (MkC s) = rep2 conTName [s]
2006
2007 repTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2008 -- Note: not Core Int; it's easier to be direct here
2009 repTupleTyCon i = do dflags <- getDynFlags
2010 rep2 tupleTName [mkIntExprInt dflags i]
2011
2012 repUnboxedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2013 -- Note: not Core Int; it's easier to be direct here
2014 repUnboxedTupleTyCon i = do dflags <- getDynFlags
2015 rep2 unboxedTupleTName [mkIntExprInt dflags i]
2016
2017 repArrowTyCon :: DsM (Core TH.TypeQ)
2018 repArrowTyCon = rep2 arrowTName []
2019
2020 repListTyCon :: DsM (Core TH.TypeQ)
2021 repListTyCon = rep2 listTName []
2022
2023 repPromotedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2024 repPromotedTyCon (MkC s) = rep2 promotedTName [s]
2025
2026 repPromotedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2027 repPromotedTupleTyCon i = do dflags <- getDynFlags
2028 rep2 promotedTupleTName [mkIntExprInt dflags i]
2029
2030 repPromotedNilTyCon :: DsM (Core TH.TypeQ)
2031 repPromotedNilTyCon = rep2 promotedNilTName []
2032
2033 repPromotedConsTyCon :: DsM (Core TH.TypeQ)
2034 repPromotedConsTyCon = rep2 promotedConsTName []
2035
2036 ------------ Kinds -------------------
2037
2038 repPlainTV :: Core TH.Name -> DsM (Core TH.TyVarBndr)
2039 repPlainTV (MkC nm) = rep2 plainTVName [nm]
2040
2041 repKindedTV :: Core TH.Name -> Core TH.Kind -> DsM (Core TH.TyVarBndr)
2042 repKindedTV (MkC nm) (MkC ki) = rep2 kindedTVName [nm, ki]
2043
2044 repKVar :: Core TH.Name -> DsM (Core TH.Kind)
2045 repKVar (MkC s) = rep2 varKName [s]
2046
2047 repKCon :: Core TH.Name -> DsM (Core TH.Kind)
2048 repKCon (MkC s) = rep2 conKName [s]
2049
2050 repKTuple :: Int -> DsM (Core TH.Kind)
2051 repKTuple i = do dflags <- getDynFlags
2052 rep2 tupleKName [mkIntExprInt dflags i]
2053
2054 repKArrow :: DsM (Core TH.Kind)
2055 repKArrow = rep2 arrowKName []
2056
2057 repKList :: DsM (Core TH.Kind)
2058 repKList = rep2 listKName []
2059
2060 repKApp :: Core TH.Kind -> Core TH.Kind -> DsM (Core TH.Kind)
2061 repKApp (MkC k1) (MkC k2) = rep2 appKName [k1, k2]
2062
2063 repKApps :: Core TH.Kind -> [Core TH.Kind] -> DsM (Core TH.Kind)
2064 repKApps f [] = return f
2065 repKApps f (k:ks) = do { f' <- repKApp f k; repKApps f' ks }
2066
2067 repKStar :: DsM (Core TH.Kind)
2068 repKStar = rep2 starKName []
2069
2070 repKConstraint :: DsM (Core TH.Kind)
2071 repKConstraint = rep2 constraintKName []
2072
2073 ----------------------------------------------------------
2074 -- Type family result signature
2075
2076 repNoSig :: DsM (Core TH.FamilyResultSig)
2077 repNoSig = rep2 noSigName []
2078
2079 repKindSig :: Core TH.Kind -> DsM (Core TH.FamilyResultSig)
2080 repKindSig (MkC ki) = rep2 kindSigName [ki]
2081
2082 repTyVarSig :: Core TH.TyVarBndr -> DsM (Core TH.FamilyResultSig)
2083 repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr]
2084
2085 ----------------------------------------------------------
2086 -- Literals
2087
2088 repLiteral :: HsLit -> DsM (Core TH.Lit)
2089 repLiteral (HsStringPrim _ bs)
2090 = do dflags <- getDynFlags
2091 word8_ty <- lookupType word8TyConName
2092 let w8s = unpack bs
2093 w8s_expr = map (\w8 -> mkCoreConApps word8DataCon
2094 [mkWordLit dflags (toInteger w8)]) w8s
2095 rep2 stringPrimLName [mkListExpr word8_ty w8s_expr]
2096 repLiteral lit
2097 = do lit' <- case lit of
2098 HsIntPrim _ i -> mk_integer i
2099 HsWordPrim _ w -> mk_integer w
2100 HsInt _ i -> mk_integer i
2101 HsFloatPrim r -> mk_rational r
2102 HsDoublePrim r -> mk_rational r
2103 HsCharPrim _ c -> mk_char c
2104 _ -> return lit
2105 lit_expr <- dsLit lit'
2106 case mb_lit_name of
2107 Just lit_name -> rep2 lit_name [lit_expr]
2108 Nothing -> notHandled "Exotic literal" (ppr lit)
2109 where
2110 mb_lit_name = case lit of
2111 HsInteger _ _ _ -> Just integerLName
2112 HsInt _ _ -> Just integerLName
2113 HsIntPrim _ _ -> Just intPrimLName
2114 HsWordPrim _ _ -> Just wordPrimLName
2115 HsFloatPrim _ -> Just floatPrimLName
2116 HsDoublePrim _ -> Just doublePrimLName
2117 HsChar _ _ -> Just charLName
2118 HsCharPrim _ _ -> Just charPrimLName
2119 HsString _ _ -> Just stringLName
2120 HsRat _ _ -> Just rationalLName
2121 _ -> Nothing
2122
2123 mk_integer :: Integer -> DsM HsLit
2124 mk_integer i = do integer_ty <- lookupType integerTyConName
2125 return $ HsInteger "" i integer_ty
2126 mk_rational :: FractionalLit -> DsM HsLit
2127 mk_rational r = do rat_ty <- lookupType rationalTyConName
2128 return $ HsRat r rat_ty
2129 mk_string :: FastString -> DsM HsLit
2130 mk_string s = return $ HsString "" s
2131
2132 mk_char :: Char -> DsM HsLit
2133 mk_char c = return $ HsChar "" c
2134
2135 repOverloadedLiteral :: HsOverLit Name -> DsM (Core TH.Lit)
2136 repOverloadedLiteral (OverLit { ol_val = val})
2137 = do { lit <- mk_lit val; repLiteral lit }
2138 -- The type Rational will be in the environment, because
2139 -- the smart constructor 'TH.Syntax.rationalL' uses it in its type,
2140 -- and rationalL is sucked in when any TH stuff is used
2141
2142 mk_lit :: OverLitVal -> DsM HsLit
2143 mk_lit (HsIntegral _ i) = mk_integer i
2144 mk_lit (HsFractional f) = mk_rational f
2145 mk_lit (HsIsString _ s) = mk_string s
2146
2147 repNameS :: Core String -> DsM (Core TH.Name)
2148 repNameS (MkC name) = rep2 mkNameSName [name]
2149
2150 --------------- Miscellaneous -------------------
2151
2152 repGensym :: Core String -> DsM (Core (TH.Q TH.Name))
2153 repGensym (MkC lit_str) = rep2 newNameName [lit_str]
2154
2155 repBindQ :: Type -> Type -- a and b
2156 -> Core (TH.Q a) -> Core (a -> TH.Q b) -> DsM (Core (TH.Q b))
2157 repBindQ ty_a ty_b (MkC x) (MkC y)
2158 = rep2 bindQName [Type ty_a, Type ty_b, x, y]
2159
2160 repSequenceQ :: Type -> Core [TH.Q a] -> DsM (Core (TH.Q [a]))
2161 repSequenceQ ty_a (MkC list)
2162 = rep2 sequenceQName [Type ty_a, list]
2163
2164 repUnboundVar :: Core TH.Name -> DsM (Core TH.ExpQ)
2165 repUnboundVar (MkC name) = rep2 unboundVarEName [name]
2166
2167 ------------ Lists -------------------
2168 -- turn a list of patterns into a single pattern matching a list
2169
2170 repList :: Name -> (a -> DsM (Core b))
2171 -> [a] -> DsM (Core [b])
2172 repList tc_name f args
2173 = do { args1 <- mapM f args
2174 ; coreList tc_name args1 }
2175
2176 coreList :: Name -- Of the TyCon of the element type
2177 -> [Core a] -> DsM (Core [a])
2178 coreList tc_name es
2179 = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) }
2180
2181 coreList' :: Type -- The element type
2182 -> [Core a] -> Core [a]
2183 coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es ))
2184
2185 nonEmptyCoreList :: [Core a] -> Core [a]
2186 -- The list must be non-empty so we can get the element type
2187 -- Otherwise use coreList
2188 nonEmptyCoreList [] = panic "coreList: empty argument"
2189 nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs))
2190
2191 coreStringLit :: String -> DsM (Core String)
2192 coreStringLit s = do { z <- mkStringExpr s; return(MkC z) }
2193
2194 ------------------- Maybe ------------------
2195
2196 -- | Construct Core expression for Nothing of a given type name
2197 coreNothing :: Name -- ^ Name of the TyCon of the element type
2198 -> DsM (Core (Maybe a))
2199 coreNothing tc_name =
2200 do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) }
2201
2202 -- | Construct Core expression for Nothing of a given type
2203 coreNothing' :: Type -- ^ The element type
2204 -> Core (Maybe a)
2205 coreNothing' elt_ty = MkC (mkNothingExpr elt_ty)
2206
2207 -- | Store given Core expression in a Just of a given type name
2208 coreJust :: Name -- ^ Name of the TyCon of the element type
2209 -> Core a -> DsM (Core (Maybe a))
2210 coreJust tc_name es
2211 = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) }
2212
2213 -- | Store given Core expression in a Just of a given type
2214 coreJust' :: Type -- ^ The element type
2215 -> Core a -> Core (Maybe a)
2216 coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es))
2217
2218 ------------ Literals & Variables -------------------
2219
2220 coreIntLit :: Int -> DsM (Core Int)
2221 coreIntLit i = do dflags <- getDynFlags
2222 return (MkC (mkIntExprInt dflags i))
2223
2224 coreVar :: Id -> Core TH.Name -- The Id has type Name
2225 coreVar id = MkC (Var id)
2226
2227 ----------------- Failure -----------------------
2228 notHandledL :: SrcSpan -> String -> SDoc -> DsM a
2229 notHandledL loc what doc
2230 | isGoodSrcSpan loc
2231 = putSrcSpanDs loc $ notHandled what doc
2232 | otherwise
2233 = notHandled what doc
2234
2235 notHandled :: String -> SDoc -> DsM a
2236 notHandled what doc = failWithDs msg
2237 where
2238 msg = hang (text what <+> ptext (sLit "not (yet) handled by Template Haskell"))
2239 2 doc