Refactor the typechecker to use ExpTypes.
[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 CoreSyn
47 import MkCore
48 import CoreUtils
49 import SrcLoc
50 import Unique
51 import BasicTypes
52 import Outputable
53 import Bag
54 import DynFlags
55 import FastString
56 import ForeignCall
57 import Util
58 import Maybes
59 import MonadUtils
60
61 import Data.ByteString ( unpack )
62 import Control.Monad
63 import Data.List
64
65 -----------------------------------------------------------------------------
66 dsBracket :: HsBracket Name -> [PendingTcSplice] -> DsM CoreExpr
67 -- Returns a CoreExpr of type TH.ExpQ
68 -- The quoted thing is parameterised over Name, even though it has
69 -- been type checked. We don't want all those type decorations!
70
71 dsBracket brack splices
72 = dsExtendMetaEnv new_bit (do_brack brack)
73 where
74 new_bit = mkNameEnv [(n, DsSplice (unLoc e)) | PendingTcSplice n e <- splices]
75
76 do_brack (VarBr _ n) = do { MkC e1 <- lookupOcc n ; return e1 }
77 do_brack (ExpBr e) = do { MkC e1 <- repLE e ; return e1 }
78 do_brack (PatBr p) = do { MkC p1 <- repTopP p ; return p1 }
79 do_brack (TypBr t) = do { MkC t1 <- repLTy t ; return t1 }
80 do_brack (DecBrG gp) = do { MkC ds1 <- repTopDs gp ; return ds1 }
81 do_brack (DecBrL _) = panic "dsBracket: unexpected DecBrL"
82 do_brack (TExpBr e) = do { MkC e1 <- repLE e ; return e1 }
83
84 {- -------------- Examples --------------------
85
86 [| \x -> x |]
87 ====>
88 gensym (unpackString "x"#) `bindQ` \ x1::String ->
89 lam (pvar x1) (var x1)
90
91
92 [| \x -> $(f [| x |]) |]
93 ====>
94 gensym (unpackString "x"#) `bindQ` \ x1::String ->
95 lam (pvar x1) (f (var x1))
96 -}
97
98
99 -------------------------------------------------------
100 -- Declarations
101 -------------------------------------------------------
102
103 repTopP :: LPat Name -> DsM (Core TH.PatQ)
104 repTopP pat = do { ss <- mkGenSyms (collectPatBinders pat)
105 ; pat' <- addBinds ss (repLP pat)
106 ; wrapGenSyms ss pat' }
107
108 repTopDs :: HsGroup Name -> DsM (Core (TH.Q [TH.Dec]))
109 repTopDs group@(HsGroup { hs_valds = valds
110 , hs_splcds = splcds
111 , hs_tyclds = tyclds
112 , hs_instds = instds
113 , hs_derivds = derivds
114 , hs_fixds = fixds
115 , hs_defds = defds
116 , hs_fords = fords
117 , hs_warnds = warnds
118 , hs_annds = annds
119 , hs_ruleds = ruleds
120 , hs_vects = vects
121 , hs_docs = docs })
122 = do { let { tv_bndrs = hsSigTvBinders valds
123 ; bndrs = tv_bndrs ++ hsGroupBinders group } ;
124 ss <- mkGenSyms bndrs ;
125
126 -- Bind all the names mainly to avoid repeated use of explicit strings.
127 -- Thus we get
128 -- do { t :: String <- genSym "T" ;
129 -- return (Data t [] ...more t's... }
130 -- The other important reason is that the output must mention
131 -- only "T", not "Foo:T" where Foo is the current module
132
133 decls <- addBinds ss (
134 do { val_ds <- rep_val_binds valds
135 ; _ <- mapM no_splice splcds
136 ; tycl_ds <- mapM repTyClD (tyClGroupConcat tyclds)
137 ; role_ds <- mapM repRoleD (concatMap group_roles tyclds)
138 ; inst_ds <- mapM repInstD instds
139 ; deriv_ds <- mapM repStandaloneDerivD derivds
140 ; fix_ds <- mapM repFixD fixds
141 ; _ <- mapM no_default_decl defds
142 ; for_ds <- mapM repForD fords
143 ; _ <- mapM no_warn (concatMap (wd_warnings . unLoc)
144 warnds)
145 ; ann_ds <- mapM repAnnD annds
146 ; rule_ds <- mapM repRuleD (concatMap (rds_rules . unLoc)
147 ruleds)
148 ; _ <- mapM no_vect vects
149 ; _ <- mapM no_doc docs
150
151 -- more needed
152 ; return (de_loc $ sort_by_loc $
153 val_ds ++ catMaybes tycl_ds ++ role_ds
154 ++ (concat fix_ds)
155 ++ inst_ds ++ rule_ds ++ for_ds
156 ++ ann_ds ++ deriv_ds) }) ;
157
158 decl_ty <- lookupType decQTyConName ;
159 let { core_list = coreList' decl_ty decls } ;
160
161 dec_ty <- lookupType decTyConName ;
162 q_decs <- repSequenceQ dec_ty core_list ;
163
164 wrapGenSyms ss q_decs
165 }
166 where
167 no_splice (L loc _)
168 = notHandledL loc "Splices within declaration brackets" empty
169 no_default_decl (L loc decl)
170 = notHandledL loc "Default declarations" (ppr decl)
171 no_warn (L loc (Warning thing _))
172 = notHandledL loc "WARNING and DEPRECATION pragmas" $
173 text "Pragma for declaration of" <+> ppr thing
174 no_vect (L loc decl)
175 = notHandledL loc "Vectorisation pragmas" (ppr decl)
176 no_doc (L loc _)
177 = notHandledL loc "Haddock documentation" empty
178
179 hsSigTvBinders :: HsValBinds Name -> [Name]
180 -- See Note [Scoped type variables in bindings]
181 hsSigTvBinders binds
182 = concatMap get_scoped_tvs sigs
183 where
184 get_scoped_tvs :: LSig Name -> [Name]
185 -- Both implicit and explicit quantified variables
186 -- We need the implicit ones for f :: forall (a::k). blah
187 -- here 'k' scopes too
188 get_scoped_tvs (L _ (TypeSig _ sig))
189 | HsIB { hsib_vars = implicit_vars
190 , hsib_body = sig1 } <- sig
191 , (explicit_vars, _) <- splitLHsForAllTy (hswc_body sig1)
192 = implicit_vars ++ map hsLTyVarName explicit_vars
193 get_scoped_tvs _ = []
194
195 sigs = case binds of
196 ValBindsIn _ sigs -> sigs
197 ValBindsOut _ sigs -> sigs
198
199
200 {- Notes
201
202 Note [Scoped type variables in bindings]
203 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
204 Consider
205 f :: forall a. a -> a
206 f x = x::a
207 Here the 'forall a' brings 'a' into scope over the binding group.
208 To achieve this we
209
210 a) Gensym a binding for 'a' at the same time as we do one for 'f'
211 collecting the relevant binders with hsSigTvBinders
212
213 b) When processing the 'forall', don't gensym
214
215 The relevant places are signposted with references to this Note
216
217 Note [Binders and occurrences]
218 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
219 When we desugar [d| data T = MkT |]
220 we want to get
221 Data "T" [] [Con "MkT" []] []
222 and *not*
223 Data "Foo:T" [] [Con "Foo:MkT" []] []
224 That is, the new data decl should fit into whatever new module it is
225 asked to fit in. We do *not* clone, though; no need for this:
226 Data "T79" ....
227
228 But if we see this:
229 data T = MkT
230 foo = reifyDecl T
231
232 then we must desugar to
233 foo = Data "Foo:T" [] [Con "Foo:MkT" []] []
234
235 So in repTopDs we bring the binders into scope with mkGenSyms and addBinds.
236 And we use lookupOcc, rather than lookupBinder
237 in repTyClD and repC.
238
239 -}
240
241 -- represent associated family instances
242 --
243 repTyClD :: LTyClDecl Name -> DsM (Maybe (SrcSpan, Core TH.DecQ))
244
245 repTyClD (L loc (FamDecl { tcdFam = fam })) = liftM Just $ repFamilyDecl (L loc fam)
246
247 repTyClD (L loc (SynDecl { tcdLName = tc, tcdTyVars = tvs, tcdRhs = rhs }))
248 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
249 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
250 repSynDecl tc1 bndrs rhs
251 ; return (Just (loc, dec)) }
252
253 repTyClD (L loc (DataDecl { tcdLName = tc, tcdTyVars = tvs, tcdDataDefn = defn }))
254 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
255 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
256 repDataDefn tc1 bndrs Nothing defn
257 ; return (Just (loc, dec)) }
258
259 repTyClD (L loc (ClassDecl { tcdCtxt = cxt, tcdLName = cls,
260 tcdTyVars = tvs, tcdFDs = fds,
261 tcdSigs = sigs, tcdMeths = meth_binds,
262 tcdATs = ats, tcdATDefs = atds }))
263 = do { cls1 <- lookupLOcc cls -- See note [Binders and occurrences]
264 ; dec <- addTyVarBinds tvs $ \bndrs ->
265 do { cxt1 <- repLContext cxt
266 ; sigs1 <- rep_sigs sigs
267 ; binds1 <- rep_binds meth_binds
268 ; fds1 <- repLFunDeps fds
269 ; ats1 <- repFamilyDecls ats
270 ; atds1 <- repAssocTyFamDefaults atds
271 ; decls1 <- coreList decQTyConName (ats1 ++ atds1 ++ sigs1 ++ binds1)
272 ; repClass cxt1 cls1 bndrs fds1 decls1
273 }
274 ; return $ Just (loc, dec)
275 }
276
277 -------------------------
278 repRoleD :: LRoleAnnotDecl Name -> DsM (SrcSpan, Core TH.DecQ)
279 repRoleD (L loc (RoleAnnotDecl tycon roles))
280 = do { tycon1 <- lookupLOcc tycon
281 ; roles1 <- mapM repRole roles
282 ; roles2 <- coreList roleTyConName roles1
283 ; dec <- repRoleAnnotD tycon1 roles2
284 ; return (loc, dec) }
285
286 -------------------------
287 repDataDefn :: Core TH.Name -> Core [TH.TyVarBndr]
288 -> Maybe (Core [TH.TypeQ])
289 -> HsDataDefn Name
290 -> DsM (Core TH.DecQ)
291 repDataDefn tc bndrs opt_tys
292 (HsDataDefn { dd_ND = new_or_data, dd_ctxt = cxt, dd_kindSig = ksig
293 , dd_cons = cons, dd_derivs = mb_derivs })
294 = do { cxt1 <- repLContext cxt
295 ; derivs1 <- repDerivs mb_derivs
296 ; case (new_or_data, cons) of
297 (NewType, [con]) -> do { con' <- repC con
298 ; ksig' <- repMaybeLKind ksig
299 ; repNewtype cxt1 tc bndrs opt_tys ksig' con'
300 derivs1 }
301 (NewType, _) -> failWithDs (text "Multiple constructors for newtype:"
302 <+> pprQuotedList
303 (getConNames $ unLoc $ head cons))
304 (DataType, _) -> do { ksig' <- repMaybeLKind ksig
305 ; consL <- mapM repC cons
306 ; cons1 <- coreList conQTyConName consL
307 ; repData cxt1 tc bndrs opt_tys ksig' cons1
308 derivs1 }
309 }
310
311 repSynDecl :: Core TH.Name -> Core [TH.TyVarBndr]
312 -> LHsType Name
313 -> DsM (Core TH.DecQ)
314 repSynDecl tc bndrs ty
315 = do { ty1 <- repLTy ty
316 ; repTySyn tc bndrs ty1 }
317
318 repFamilyDecl :: LFamilyDecl Name -> DsM (SrcSpan, Core TH.DecQ)
319 repFamilyDecl decl@(L loc (FamilyDecl { fdInfo = info,
320 fdLName = tc,
321 fdTyVars = tvs,
322 fdResultSig = L _ resultSig,
323 fdInjectivityAnn = injectivity }))
324 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
325 ; let mkHsQTvs :: [LHsTyVarBndr Name] -> LHsQTyVars Name
326 mkHsQTvs tvs = HsQTvs { hsq_implicit = [], hsq_explicit = tvs }
327 resTyVar = case resultSig of
328 TyVarSig bndr -> mkHsQTvs [bndr]
329 _ -> mkHsQTvs []
330 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
331 addTyClTyVarBinds resTyVar $ \_ ->
332 case info of
333 ClosedTypeFamily Nothing ->
334 notHandled "abstract closed type family" (ppr decl)
335 ClosedTypeFamily (Just eqns) ->
336 do { eqns1 <- mapM repTyFamEqn eqns
337 ; eqns2 <- coreList tySynEqnQTyConName eqns1
338 ; result <- repFamilyResultSig resultSig
339 ; inj <- repInjectivityAnn injectivity
340 ; repClosedFamilyD tc1 bndrs result inj eqns2 }
341 OpenTypeFamily ->
342 do { result <- repFamilyResultSig resultSig
343 ; inj <- repInjectivityAnn injectivity
344 ; repOpenFamilyD tc1 bndrs result inj }
345 DataFamily ->
346 do { kind <- repFamilyResultSigToMaybeKind resultSig
347 ; repDataFamilyD tc1 bndrs kind }
348 ; return (loc, dec)
349 }
350
351 -- | Represent result signature of a type family
352 repFamilyResultSig :: FamilyResultSig Name -> DsM (Core TH.FamilyResultSig)
353 repFamilyResultSig NoSig = repNoSig
354 repFamilyResultSig (KindSig ki) = do { ki' <- repLKind ki
355 ; repKindSig ki' }
356 repFamilyResultSig (TyVarSig bndr) = do { bndr' <- repTyVarBndr bndr
357 ; repTyVarSig bndr' }
358
359 -- | Represent result signature using a Maybe Kind. Used with data families,
360 -- where the result signature can be either missing or a kind but never a named
361 -- result variable.
362 repFamilyResultSigToMaybeKind :: FamilyResultSig Name
363 -> DsM (Core (Maybe TH.Kind))
364 repFamilyResultSigToMaybeKind NoSig =
365 do { coreNothing kindTyConName }
366 repFamilyResultSigToMaybeKind (KindSig ki) =
367 do { ki' <- repLKind ki
368 ; coreJust kindTyConName ki' }
369 repFamilyResultSigToMaybeKind _ = panic "repFamilyResultSigToMaybeKind"
370
371 -- | Represent injectivity annotation of a type family
372 repInjectivityAnn :: Maybe (LInjectivityAnn Name)
373 -> DsM (Core (Maybe TH.InjectivityAnn))
374 repInjectivityAnn Nothing =
375 do { coreNothing injAnnTyConName }
376 repInjectivityAnn (Just (L _ (InjectivityAnn lhs rhs))) =
377 do { lhs' <- lookupBinder (unLoc lhs)
378 ; rhs1 <- mapM (lookupBinder . unLoc) rhs
379 ; rhs2 <- coreList nameTyConName rhs1
380 ; injAnn <- rep2 injectivityAnnName [unC lhs', unC rhs2]
381 ; coreJust injAnnTyConName injAnn }
382
383 repFamilyDecls :: [LFamilyDecl Name] -> DsM [Core TH.DecQ]
384 repFamilyDecls fds = liftM de_loc (mapM repFamilyDecl fds)
385
386 repAssocTyFamDefaults :: [LTyFamDefltEqn Name] -> DsM [Core TH.DecQ]
387 repAssocTyFamDefaults = mapM rep_deflt
388 where
389 -- very like repTyFamEqn, but different in the details
390 rep_deflt :: LTyFamDefltEqn Name -> DsM (Core TH.DecQ)
391 rep_deflt (L _ (TyFamEqn { tfe_tycon = tc
392 , tfe_pats = bndrs
393 , tfe_rhs = rhs }))
394 = addTyClTyVarBinds bndrs $ \ _ ->
395 do { tc1 <- lookupLOcc tc
396 ; tys1 <- repLTys (hsLTyVarBndrsToTypes bndrs)
397 ; tys2 <- coreList typeQTyConName tys1
398 ; rhs1 <- repLTy rhs
399 ; eqn1 <- repTySynEqn tys2 rhs1
400 ; repTySynInst tc1 eqn1 }
401
402 -------------------------
403 -- represent fundeps
404 --
405 repLFunDeps :: [Located (FunDep (Located Name))] -> DsM (Core [TH.FunDep])
406 repLFunDeps fds = repList funDepTyConName repLFunDep fds
407
408 repLFunDep :: Located (FunDep (Located Name)) -> DsM (Core TH.FunDep)
409 repLFunDep (L _ (xs, ys))
410 = do xs' <- repList nameTyConName (lookupBinder . unLoc) xs
411 ys' <- repList nameTyConName (lookupBinder . unLoc) ys
412 repFunDep xs' ys'
413
414 -- Represent instance declarations
415 --
416 repInstD :: LInstDecl Name -> DsM (SrcSpan, Core TH.DecQ)
417 repInstD (L loc (TyFamInstD { tfid_inst = fi_decl }))
418 = do { dec <- repTyFamInstD fi_decl
419 ; return (loc, dec) }
420 repInstD (L loc (DataFamInstD { dfid_inst = fi_decl }))
421 = do { dec <- repDataFamInstD fi_decl
422 ; return (loc, dec) }
423 repInstD (L loc (ClsInstD { cid_inst = cls_decl }))
424 = do { dec <- repClsInstD cls_decl
425 ; return (loc, dec) }
426
427 repClsInstD :: ClsInstDecl Name -> DsM (Core TH.DecQ)
428 repClsInstD (ClsInstDecl { cid_poly_ty = ty, cid_binds = binds
429 , cid_sigs = prags, cid_tyfam_insts = ats
430 , cid_datafam_insts = adts })
431 = addSimpleTyVarBinds tvs $
432 -- We must bring the type variables into scope, so their
433 -- occurrences don't fail, even though the binders don't
434 -- appear in the resulting data structure
435 --
436 -- But we do NOT bring the binders of 'binds' into scope
437 -- because they are properly regarded as occurrences
438 -- For example, the method names should be bound to
439 -- the selector Ids, not to fresh names (Trac #5410)
440 --
441 do { cxt1 <- repLContext cxt
442 ; inst_ty1 <- repLTy inst_ty
443 ; binds1 <- rep_binds binds
444 ; prags1 <- rep_sigs prags
445 ; ats1 <- mapM (repTyFamInstD . unLoc) ats
446 ; adts1 <- mapM (repDataFamInstD . unLoc) adts
447 ; decls <- coreList decQTyConName (ats1 ++ adts1 ++ binds1 ++ prags1)
448 ; repInst cxt1 inst_ty1 decls }
449 where
450 (tvs, cxt, inst_ty) = splitLHsInstDeclTy ty
451
452 repStandaloneDerivD :: LDerivDecl Name -> DsM (SrcSpan, Core TH.DecQ)
453 repStandaloneDerivD (L loc (DerivDecl { deriv_type = ty }))
454 = do { dec <- addSimpleTyVarBinds tvs $
455 do { cxt' <- repLContext cxt
456 ; inst_ty' <- repLTy inst_ty
457 ; repDeriv cxt' inst_ty' }
458 ; return (loc, dec) }
459 where
460 (tvs, cxt, inst_ty) = splitLHsInstDeclTy ty
461
462 repTyFamInstD :: TyFamInstDecl Name -> DsM (Core TH.DecQ)
463 repTyFamInstD decl@(TyFamInstDecl { tfid_eqn = eqn })
464 = do { let tc_name = tyFamInstDeclLName decl
465 ; tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
466 ; eqn1 <- repTyFamEqn eqn
467 ; repTySynInst tc eqn1 }
468
469 repTyFamEqn :: LTyFamInstEqn Name -> DsM (Core TH.TySynEqnQ)
470 repTyFamEqn (L _ (TyFamEqn { tfe_pats = HsIB { hsib_body = tys
471 , hsib_vars = var_names }
472 , tfe_rhs = rhs }))
473 = do { let hs_tvs = HsQTvs { hsq_implicit = var_names
474 , hsq_explicit = [] } -- Yuk
475 ; addTyClTyVarBinds hs_tvs $ \ _ ->
476 do { tys1 <- repLTys tys
477 ; tys2 <- coreList typeQTyConName tys1
478 ; rhs1 <- repLTy rhs
479 ; repTySynEqn tys2 rhs1 } }
480
481 repDataFamInstD :: DataFamInstDecl Name -> DsM (Core TH.DecQ)
482 repDataFamInstD (DataFamInstDecl { dfid_tycon = tc_name
483 , dfid_pats = HsIB { hsib_body = tys, hsib_vars = var_names }
484 , dfid_defn = defn })
485 = do { tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
486 ; let hs_tvs = HsQTvs { hsq_implicit = var_names
487 , hsq_explicit = [] } -- Yuk
488 ; addTyClTyVarBinds hs_tvs $ \ bndrs ->
489 do { tys1 <- repList typeQTyConName repLTy tys
490 ; repDataDefn tc bndrs (Just tys1) defn } }
491
492 repForD :: Located (ForeignDecl Name) -> DsM (SrcSpan, Core TH.DecQ)
493 repForD (L loc (ForeignImport { fd_name = name, fd_sig_ty = typ
494 , fd_fi = CImport (L _ cc) (L _ s) mch cis _ }))
495 = do MkC name' <- lookupLOcc name
496 MkC typ' <- repHsSigType typ
497 MkC cc' <- repCCallConv cc
498 MkC s' <- repSafety s
499 cis' <- conv_cimportspec cis
500 MkC str <- coreStringLit (static ++ chStr ++ cis')
501 dec <- rep2 forImpDName [cc', s', str, name', typ']
502 return (loc, dec)
503 where
504 conv_cimportspec (CLabel cls) = notHandled "Foreign label" (doubleQuotes (ppr cls))
505 conv_cimportspec (CFunction DynamicTarget) = return "dynamic"
506 conv_cimportspec (CFunction (StaticTarget _ fs _ True))
507 = return (unpackFS fs)
508 conv_cimportspec (CFunction (StaticTarget _ _ _ False))
509 = panic "conv_cimportspec: values not supported yet"
510 conv_cimportspec CWrapper = return "wrapper"
511 -- these calling conventions do not support headers and the static keyword
512 raw_cconv = cc == PrimCallConv || cc == JavaScriptCallConv
513 static = case cis of
514 CFunction (StaticTarget _ _ _ _) | not raw_cconv -> "static "
515 _ -> ""
516 chStr = case mch of
517 Just (Header _ h) | not raw_cconv -> unpackFS h ++ " "
518 _ -> ""
519 repForD decl = notHandled "Foreign declaration" (ppr decl)
520
521 repCCallConv :: CCallConv -> DsM (Core TH.Callconv)
522 repCCallConv CCallConv = rep2 cCallName []
523 repCCallConv StdCallConv = rep2 stdCallName []
524 repCCallConv CApiConv = rep2 cApiCallName []
525 repCCallConv PrimCallConv = rep2 primCallName []
526 repCCallConv JavaScriptCallConv = rep2 javaScriptCallName []
527
528 repSafety :: Safety -> DsM (Core TH.Safety)
529 repSafety PlayRisky = rep2 unsafeName []
530 repSafety PlayInterruptible = rep2 interruptibleName []
531 repSafety PlaySafe = rep2 safeName []
532
533 repFixD :: LFixitySig Name -> DsM [(SrcSpan, Core TH.DecQ)]
534 repFixD (L loc (FixitySig names (Fixity _ prec dir)))
535 = do { MkC prec' <- coreIntLit prec
536 ; let rep_fn = case dir of
537 InfixL -> infixLDName
538 InfixR -> infixRDName
539 InfixN -> infixNDName
540 ; let do_one name
541 = do { MkC name' <- lookupLOcc name
542 ; dec <- rep2 rep_fn [prec', name']
543 ; return (loc,dec) }
544 ; mapM do_one names }
545
546 repRuleD :: LRuleDecl Name -> DsM (SrcSpan, Core TH.DecQ)
547 repRuleD (L loc (HsRule n act bndrs lhs _ rhs _))
548 = do { let bndr_names = concatMap ruleBndrNames bndrs
549 ; ss <- mkGenSyms bndr_names
550 ; rule1 <- addBinds ss $
551 do { bndrs' <- repList ruleBndrQTyConName repRuleBndr bndrs
552 ; n' <- coreStringLit $ unpackFS $ snd $ unLoc n
553 ; act' <- repPhases act
554 ; lhs' <- repLE lhs
555 ; rhs' <- repLE rhs
556 ; repPragRule n' bndrs' lhs' rhs' act' }
557 ; rule2 <- wrapGenSyms ss rule1
558 ; return (loc, rule2) }
559
560 ruleBndrNames :: LRuleBndr Name -> [Name]
561 ruleBndrNames (L _ (RuleBndr n)) = [unLoc n]
562 ruleBndrNames (L _ (RuleBndrSig n sig))
563 | HsIB { hsib_vars = vars } <- sig
564 = unLoc n : vars
565
566 repRuleBndr :: LRuleBndr Name -> DsM (Core TH.RuleBndrQ)
567 repRuleBndr (L _ (RuleBndr n))
568 = do { MkC n' <- lookupLBinder n
569 ; rep2 ruleVarName [n'] }
570 repRuleBndr (L _ (RuleBndrSig n sig))
571 = do { MkC n' <- lookupLBinder n
572 ; MkC ty' <- repLTy (hsSigWcType sig)
573 ; rep2 typedRuleVarName [n', ty'] }
574
575 repAnnD :: LAnnDecl Name -> DsM (SrcSpan, Core TH.DecQ)
576 repAnnD (L loc (HsAnnotation _ ann_prov (L _ exp)))
577 = do { target <- repAnnProv ann_prov
578 ; exp' <- repE exp
579 ; dec <- repPragAnn target exp'
580 ; return (loc, dec) }
581
582 repAnnProv :: AnnProvenance Name -> DsM (Core TH.AnnTarget)
583 repAnnProv (ValueAnnProvenance (L _ n))
584 = do { MkC n' <- globalVar n -- ANNs are allowed only at top-level
585 ; rep2 valueAnnotationName [ n' ] }
586 repAnnProv (TypeAnnProvenance (L _ n))
587 = do { MkC n' <- globalVar n
588 ; rep2 typeAnnotationName [ n' ] }
589 repAnnProv ModuleAnnProvenance
590 = rep2 moduleAnnotationName []
591
592 -------------------------------------------------------
593 -- Constructors
594 -------------------------------------------------------
595
596 repC :: LConDecl Name -> DsM (Core TH.ConQ)
597 repC (L _ (ConDeclH98 { con_name = con
598 , con_qvars = Nothing, con_cxt = Nothing
599 , con_details = details }))
600 = repDataCon con details
601
602 repC (L _ (ConDeclH98 { con_name = con
603 , con_qvars = mcon_tvs, con_cxt = mcxt
604 , con_details = details }))
605 = do { let con_tvs = fromMaybe emptyLHsQTvs mcon_tvs
606 ctxt = unLoc $ fromMaybe (noLoc []) mcxt
607 ; addTyVarBinds con_tvs $ \ ex_bndrs ->
608 do { c' <- repDataCon con details
609 ; ctxt' <- repContext ctxt
610 ; if isEmptyLHsQTvs con_tvs && null ctxt
611 then return c'
612 else rep2 forallCName ([unC ex_bndrs, unC ctxt', unC c'])
613 }
614 }
615
616 repC (L _ (ConDeclGADT { con_names = cons
617 , con_type = res_ty@(HsIB { hsib_vars = con_vars })}))
618 | (details, res_ty', L _ [] , []) <- gadtDetails
619 , [] <- con_vars
620 -- no implicit or explicit variables, no context = no need for a forall
621 = do { let doc = text "In the constructor for " <+> ppr (head cons)
622 ; (hs_details, gadt_res_ty) <-
623 updateGadtResult failWithDs doc details res_ty'
624 ; repGadtDataCons cons hs_details gadt_res_ty }
625
626 | (details,res_ty',ctxt, tvs) <- gadtDetails
627 = do { let doc = text "In the constructor for " <+> ppr (head cons)
628 con_tvs = HsQTvs { hsq_implicit = []
629 , hsq_explicit = (map (noLoc . UserTyVar . noLoc)
630 con_vars) ++ tvs }
631 ; addTyVarBinds con_tvs $ \ ex_bndrs -> do
632 { (hs_details, gadt_res_ty) <-
633 updateGadtResult failWithDs doc details res_ty'
634 ; c' <- repGadtDataCons cons hs_details gadt_res_ty
635 ; ctxt' <- repContext (unLoc ctxt)
636 ; rep2 forallCName ([unC ex_bndrs, unC ctxt', unC c']) } }
637 where
638 gadtDetails = gadtDeclDetails res_ty
639
640 repSrcUnpackedness :: SrcUnpackedness -> DsM (Core TH.SourceUnpackednessQ)
641 repSrcUnpackedness SrcUnpack = rep2 sourceUnpackName []
642 repSrcUnpackedness SrcNoUnpack = rep2 sourceNoUnpackName []
643 repSrcUnpackedness NoSrcUnpack = rep2 noSourceUnpackednessName []
644
645 repSrcStrictness :: SrcStrictness -> DsM (Core TH.SourceStrictnessQ)
646 repSrcStrictness SrcLazy = rep2 sourceLazyName []
647 repSrcStrictness SrcStrict = rep2 sourceStrictName []
648 repSrcStrictness NoSrcStrict = rep2 noSourceStrictnessName []
649
650 repBangTy :: LBangType Name -> DsM (Core (TH.BangTypeQ))
651 repBangTy ty = do
652 MkC u <- repSrcUnpackedness su'
653 MkC s <- repSrcStrictness ss'
654 MkC b <- rep2 bangName [u, s]
655 MkC t <- repLTy ty'
656 rep2 bangTypeName [b, t]
657 where
658 (su', ss', ty') = case ty of
659 L _ (HsBangTy (HsSrcBang _ su ss) ty) -> (su, ss, ty)
660 _ -> (NoSrcUnpack, NoSrcStrict, ty)
661
662 -------------------------------------------------------
663 -- Deriving clause
664 -------------------------------------------------------
665
666 repDerivs :: HsDeriving Name -> DsM (Core TH.CxtQ)
667 repDerivs deriv = do
668 let clauses = case deriv of
669 Nothing -> []
670 Just (L _ ctxt) -> ctxt
671 tys <- repList typeQTyConName
672 (rep_deriv . hsSigType)
673 clauses
674 :: DsM (Core [TH.PredQ])
675 repCtxt tys
676 where
677 rep_deriv :: LHsType Name -> DsM (Core TH.TypeQ)
678 rep_deriv (L _ ty) = repTy ty
679
680 -------------------------------------------------------
681 -- Signatures in a class decl, or a group of bindings
682 -------------------------------------------------------
683
684 rep_sigs :: [LSig Name] -> DsM [Core TH.DecQ]
685 rep_sigs sigs = do locs_cores <- rep_sigs' sigs
686 return $ de_loc $ sort_by_loc locs_cores
687
688 rep_sigs' :: [LSig Name] -> DsM [(SrcSpan, Core TH.DecQ)]
689 -- We silently ignore ones we don't recognise
690 rep_sigs' sigs = do { sigs1 <- mapM rep_sig sigs ;
691 return (concat sigs1) }
692
693 rep_sig :: LSig Name -> DsM [(SrcSpan, Core TH.DecQ)]
694 rep_sig (L loc (TypeSig nms ty)) = mapM (rep_wc_ty_sig sigDName loc ty) nms
695 rep_sig (L _ (PatSynSig {})) = notHandled "Pattern type signatures" empty
696 rep_sig (L loc (ClassOpSig is_deflt nms ty))
697 | is_deflt = mapM (rep_ty_sig defaultSigDName loc ty) nms
698 | otherwise = mapM (rep_ty_sig sigDName loc ty) nms
699 rep_sig d@(L _ (IdSig {})) = pprPanic "rep_sig IdSig" (ppr d)
700 rep_sig (L _ (FixSig {})) = return [] -- fixity sigs at top level
701 rep_sig (L loc (InlineSig nm ispec)) = rep_inline nm ispec loc
702 rep_sig (L loc (SpecSig nm tys ispec))
703 = concatMapM (\t -> rep_specialise nm t ispec loc) tys
704 rep_sig (L loc (SpecInstSig _ ty)) = rep_specialiseInst ty loc
705 rep_sig (L _ (MinimalSig {})) = notHandled "MINIMAL pragmas" empty
706
707 rep_ty_sig :: Name -> SrcSpan -> LHsSigType Name -> Located Name
708 -> DsM (SrcSpan, Core TH.DecQ)
709 rep_ty_sig mk_sig loc sig_ty nm
710 = do { nm1 <- lookupLOcc nm
711 ; ty1 <- repHsSigType sig_ty
712 ; sig <- repProto mk_sig nm1 ty1
713 ; return (loc, sig) }
714
715 rep_wc_ty_sig :: Name -> SrcSpan -> LHsSigWcType Name -> Located Name
716 -> DsM (SrcSpan, Core TH.DecQ)
717 -- We must special-case the top-level explicit for-all of a TypeSig
718 -- See Note [Scoped type variables in bindings]
719 rep_wc_ty_sig mk_sig loc sig_ty nm
720 | HsIB { hsib_vars = implicit_tvs, hsib_body = sig1 } <- sig_ty
721 , (explicit_tvs, ctxt, ty) <- splitLHsSigmaTy (hswc_body sig1)
722 = do { nm1 <- lookupLOcc nm
723 ; let rep_in_scope_tv tv = do { name <- lookupBinder (hsLTyVarName tv)
724 ; repTyVarBndrWithKind tv name }
725 all_tvs = map (noLoc . UserTyVar . noLoc) implicit_tvs ++ explicit_tvs
726 ; th_tvs <- repList tyVarBndrTyConName rep_in_scope_tv all_tvs
727 ; th_ctxt <- repLContext ctxt
728 ; th_ty <- repLTy ty
729 ; ty1 <- if null all_tvs && null (unLoc ctxt)
730 then return th_ty
731 else repTForall th_tvs th_ctxt th_ty
732 ; sig <- repProto mk_sig nm1 ty1
733 ; return (loc, sig) }
734
735 rep_inline :: Located Name
736 -> InlinePragma -- Never defaultInlinePragma
737 -> SrcSpan
738 -> DsM [(SrcSpan, Core TH.DecQ)]
739 rep_inline nm ispec loc
740 = do { nm1 <- lookupLOcc nm
741 ; inline <- repInline $ inl_inline ispec
742 ; rm <- repRuleMatch $ inl_rule ispec
743 ; phases <- repPhases $ inl_act ispec
744 ; pragma <- repPragInl nm1 inline rm phases
745 ; return [(loc, pragma)]
746 }
747
748 rep_specialise :: Located Name -> LHsSigType Name -> InlinePragma -> SrcSpan
749 -> DsM [(SrcSpan, Core TH.DecQ)]
750 rep_specialise nm ty ispec loc
751 = do { nm1 <- lookupLOcc nm
752 ; ty1 <- repHsSigType ty
753 ; phases <- repPhases $ inl_act ispec
754 ; let inline = inl_inline ispec
755 ; pragma <- if isEmptyInlineSpec inline
756 then -- SPECIALISE
757 repPragSpec nm1 ty1 phases
758 else -- SPECIALISE INLINE
759 do { inline1 <- repInline inline
760 ; repPragSpecInl nm1 ty1 inline1 phases }
761 ; return [(loc, pragma)]
762 }
763
764 rep_specialiseInst :: LHsSigType Name -> SrcSpan -> DsM [(SrcSpan, Core TH.DecQ)]
765 rep_specialiseInst ty loc
766 = do { ty1 <- repHsSigType ty
767 ; pragma <- repPragSpecInst ty1
768 ; return [(loc, pragma)] }
769
770 repInline :: InlineSpec -> DsM (Core TH.Inline)
771 repInline NoInline = dataCon noInlineDataConName
772 repInline Inline = dataCon inlineDataConName
773 repInline Inlinable = dataCon inlinableDataConName
774 repInline spec = notHandled "repInline" (ppr spec)
775
776 repRuleMatch :: RuleMatchInfo -> DsM (Core TH.RuleMatch)
777 repRuleMatch ConLike = dataCon conLikeDataConName
778 repRuleMatch FunLike = dataCon funLikeDataConName
779
780 repPhases :: Activation -> DsM (Core TH.Phases)
781 repPhases (ActiveBefore _ i) = do { MkC arg <- coreIntLit i
782 ; dataCon' beforePhaseDataConName [arg] }
783 repPhases (ActiveAfter _ i) = do { MkC arg <- coreIntLit i
784 ; dataCon' fromPhaseDataConName [arg] }
785 repPhases _ = dataCon allPhasesDataConName
786
787 -------------------------------------------------------
788 -- Types
789 -------------------------------------------------------
790
791 addSimpleTyVarBinds :: [Name] -- the binders to be added
792 -> DsM (Core (TH.Q a)) -- action in the ext env
793 -> DsM (Core (TH.Q a))
794 addSimpleTyVarBinds names thing_inside
795 = do { fresh_names <- mkGenSyms names
796 ; term <- addBinds fresh_names thing_inside
797 ; wrapGenSyms fresh_names term }
798
799 addTyVarBinds :: LHsQTyVars Name -- the binders to be added
800 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a))) -- action in the ext env
801 -> DsM (Core (TH.Q a))
802 -- gensym a list of type variables and enter them into the meta environment;
803 -- the computations passed as the second argument is executed in that extended
804 -- meta environment and gets the *new* names on Core-level as an argument
805
806 addTyVarBinds (HsQTvs { hsq_implicit = imp_tvs, hsq_explicit = exp_tvs }) m
807 = do { fresh_imp_names <- mkGenSyms imp_tvs
808 ; fresh_exp_names <- mkGenSyms (map hsLTyVarName exp_tvs)
809 ; let fresh_names = fresh_imp_names ++ fresh_exp_names
810 ; term <- addBinds fresh_names $
811 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr
812 (exp_tvs `zip` fresh_exp_names)
813 ; m kbs }
814 ; wrapGenSyms fresh_names term }
815 where
816 mk_tv_bndr (tv, (_,v)) = repTyVarBndrWithKind tv (coreVar v)
817
818 addTyClTyVarBinds :: LHsQTyVars Name
819 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a)))
820 -> DsM (Core (TH.Q a))
821
822 -- Used for data/newtype declarations, and family instances,
823 -- so that the nested type variables work right
824 -- instance C (T a) where
825 -- type W (T a) = blah
826 -- The 'a' in the type instance is the one bound by the instance decl
827 addTyClTyVarBinds tvs m
828 = do { let tv_names = hsAllLTyVarNames tvs
829 ; env <- dsGetMetaEnv
830 ; freshNames <- mkGenSyms (filterOut (`elemNameEnv` env) tv_names)
831 -- Make fresh names for the ones that are not already in scope
832 -- This makes things work for family declarations
833
834 ; term <- addBinds freshNames $
835 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr (hsQTvExplicit tvs)
836 ; m kbs }
837
838 ; wrapGenSyms freshNames term }
839 where
840 mk_tv_bndr tv = do { v <- lookupBinder (hsLTyVarName tv)
841 ; repTyVarBndrWithKind tv v }
842
843 -- Produce kinded binder constructors from the Haskell tyvar binders
844 --
845 repTyVarBndrWithKind :: LHsTyVarBndr Name
846 -> Core TH.Name -> DsM (Core TH.TyVarBndr)
847 repTyVarBndrWithKind (L _ (UserTyVar _)) nm
848 = repPlainTV nm
849 repTyVarBndrWithKind (L _ (KindedTyVar _ ki)) nm
850 = repLKind ki >>= repKindedTV nm
851
852 -- | Represent a type variable binder
853 repTyVarBndr :: LHsTyVarBndr Name -> DsM (Core TH.TyVarBndr)
854 repTyVarBndr (L _ (UserTyVar (L _ nm)) )= do { nm' <- lookupBinder nm
855 ; repPlainTV nm' }
856 repTyVarBndr (L _ (KindedTyVar (L _ nm) ki)) = do { nm' <- lookupBinder nm
857 ; ki' <- repLKind ki
858 ; repKindedTV nm' ki' }
859
860 -- represent a type context
861 --
862 repLContext :: LHsContext Name -> DsM (Core TH.CxtQ)
863 repLContext (L _ ctxt) = repContext ctxt
864
865 repContext :: HsContext Name -> DsM (Core TH.CxtQ)
866 repContext ctxt = do preds <- repList typeQTyConName repLTy ctxt
867 repCtxt preds
868
869 repHsSigType :: LHsSigType Name -> DsM (Core TH.TypeQ)
870 repHsSigType ty = repLTy (hsSigType ty)
871
872 repHsSigWcType :: LHsSigWcType Name -> DsM (Core TH.TypeQ)
873 repHsSigWcType (HsIB { hsib_vars = vars
874 , hsib_body = sig1 })
875 | (explicit_tvs, ctxt, ty) <- splitLHsSigmaTy (hswc_body sig1)
876 = addTyVarBinds (HsQTvs { hsq_implicit = []
877 , hsq_explicit = map (noLoc . UserTyVar . noLoc) vars ++
878 explicit_tvs })
879 $ \ th_tvs ->
880 do { th_ctxt <- repLContext ctxt
881 ; th_ty <- repLTy ty
882 ; if null vars && null explicit_tvs && null (unLoc ctxt)
883 then return th_ty
884 else repTForall th_tvs th_ctxt th_ty }
885
886 -- yield the representation of a list of types
887 --
888 repLTys :: [LHsType Name] -> DsM [Core TH.TypeQ]
889 repLTys tys = mapM repLTy tys
890
891 -- represent a type
892 --
893 repLTy :: LHsType Name -> DsM (Core TH.TypeQ)
894 repLTy (L _ ty) = repTy ty
895
896 repForall :: HsType Name -> DsM (Core TH.TypeQ)
897 -- Arg of repForall is always HsForAllTy or HsQualTy
898 repForall ty
899 | (tvs, ctxt, tau) <- splitLHsSigmaTy (noLoc ty)
900 = addTyVarBinds (HsQTvs { hsq_implicit = [], hsq_explicit = tvs}) $ \bndrs ->
901 do { ctxt1 <- repLContext ctxt
902 ; ty1 <- repLTy tau
903 ; repTForall bndrs ctxt1 ty1 }
904
905 repTy :: HsType Name -> DsM (Core TH.TypeQ)
906 repTy ty@(HsForAllTy {}) = repForall ty
907 repTy ty@(HsQualTy {}) = repForall ty
908
909 repTy (HsTyVar (L _ n))
910 | isTvOcc occ = do tv1 <- lookupOcc n
911 repTvar tv1
912 | isDataOcc occ = do tc1 <- lookupOcc n
913 repPromotedDataCon tc1
914 | n == eqTyConName = repTequality
915 | otherwise = do tc1 <- lookupOcc n
916 repNamedTyCon tc1
917 where
918 occ = nameOccName n
919
920 repTy (HsAppTy f a) = do
921 f1 <- repLTy f
922 a1 <- repLTy a
923 repTapp f1 a1
924 repTy (HsFunTy f a) = do
925 f1 <- repLTy f
926 a1 <- repLTy a
927 tcon <- repArrowTyCon
928 repTapps tcon [f1, a1]
929 repTy (HsListTy t) = do
930 t1 <- repLTy t
931 tcon <- repListTyCon
932 repTapp tcon t1
933 repTy (HsPArrTy t) = do
934 t1 <- repLTy t
935 tcon <- repTy (HsTyVar (noLoc (tyConName parrTyCon)))
936 repTapp tcon t1
937 repTy (HsTupleTy HsUnboxedTuple tys) = do
938 tys1 <- repLTys tys
939 tcon <- repUnboxedTupleTyCon (length tys)
940 repTapps tcon tys1
941 repTy (HsTupleTy _ tys) = do tys1 <- repLTys tys
942 tcon <- repTupleTyCon (length tys)
943 repTapps tcon tys1
944 repTy (HsOpTy ty1 n ty2) = repLTy ((nlHsTyVar (unLoc n) `nlHsAppTy` ty1)
945 `nlHsAppTy` ty2)
946 repTy (HsParTy t) = repLTy t
947 repTy (HsEqTy t1 t2) = do
948 t1' <- repLTy t1
949 t2' <- repLTy t2
950 eq <- repTequality
951 repTapps eq [t1', t2']
952 repTy (HsKindSig t k) = do
953 t1 <- repLTy t
954 k1 <- repLKind k
955 repTSig t1 k1
956 repTy (HsSpliceTy splice _) = repSplice splice
957 repTy (HsExplicitListTy _ tys) = do
958 tys1 <- repLTys tys
959 repTPromotedList tys1
960 repTy (HsExplicitTupleTy _ tys) = do
961 tys1 <- repLTys tys
962 tcon <- repPromotedTupleTyCon (length tys)
963 repTapps tcon tys1
964 repTy (HsTyLit lit) = do
965 lit' <- repTyLit lit
966 repTLit lit'
967 repTy (HsWildCardTy (AnonWildCard _)) = repTWildCard
968
969 repTy ty = notHandled "Exotic form of type" (ppr ty)
970
971 repTyLit :: HsTyLit -> DsM (Core TH.TyLitQ)
972 repTyLit (HsNumTy _ i) = do iExpr <- mkIntegerExpr i
973 rep2 numTyLitName [iExpr]
974 repTyLit (HsStrTy _ s) = do { s' <- mkStringExprFS s
975 ; rep2 strTyLitName [s']
976 }
977
978 -- represent a kind
979 --
980 repLKind :: LHsKind Name -> DsM (Core TH.Kind)
981 repLKind ki
982 = do { let (kis, ki') = splitHsFunType ki
983 ; kis_rep <- mapM repLKind kis
984 ; ki'_rep <- repNonArrowLKind ki'
985 ; kcon <- repKArrow
986 ; let f k1 k2 = repKApp kcon k1 >>= flip repKApp k2
987 ; foldrM f ki'_rep kis_rep
988 }
989
990 -- | Represent a kind wrapped in a Maybe
991 repMaybeLKind :: Maybe (LHsKind Name)
992 -> DsM (Core (Maybe TH.Kind))
993 repMaybeLKind Nothing =
994 do { coreNothing kindTyConName }
995 repMaybeLKind (Just ki) =
996 do { ki' <- repLKind ki
997 ; coreJust kindTyConName ki' }
998
999 repNonArrowLKind :: LHsKind Name -> DsM (Core TH.Kind)
1000 repNonArrowLKind (L _ ki) = repNonArrowKind ki
1001
1002 repNonArrowKind :: HsKind Name -> DsM (Core TH.Kind)
1003 repNonArrowKind (HsTyVar (L _ name))
1004 | isLiftedTypeKindTyConName name = repKStar
1005 | name `hasKey` constraintKindTyConKey = repKConstraint
1006 | isTvOcc (nameOccName name) = lookupOcc name >>= repKVar
1007 | otherwise = lookupOcc name >>= repKCon
1008 repNonArrowKind (HsAppTy f a) = do { f' <- repLKind f
1009 ; a' <- repLKind a
1010 ; repKApp f' a'
1011 }
1012 repNonArrowKind (HsListTy k) = do { k' <- repLKind k
1013 ; kcon <- repKList
1014 ; repKApp kcon k'
1015 }
1016 repNonArrowKind (HsTupleTy _ ks) = do { ks' <- mapM repLKind ks
1017 ; kcon <- repKTuple (length ks)
1018 ; repKApps kcon ks'
1019 }
1020 repNonArrowKind k = notHandled "Exotic form of kind" (ppr k)
1021
1022 repRole :: Located (Maybe Role) -> DsM (Core TH.Role)
1023 repRole (L _ (Just Nominal)) = rep2 nominalRName []
1024 repRole (L _ (Just Representational)) = rep2 representationalRName []
1025 repRole (L _ (Just Phantom)) = rep2 phantomRName []
1026 repRole (L _ Nothing) = rep2 inferRName []
1027
1028 -----------------------------------------------------------------------------
1029 -- Splices
1030 -----------------------------------------------------------------------------
1031
1032 repSplice :: HsSplice Name -> DsM (Core a)
1033 -- See Note [How brackets and nested splices are handled] in TcSplice
1034 -- We return a CoreExpr of any old type; the context should know
1035 repSplice (HsTypedSplice n _) = rep_splice n
1036 repSplice (HsUntypedSplice n _) = rep_splice n
1037 repSplice (HsQuasiQuote n _ _ _) = rep_splice n
1038
1039 rep_splice :: Name -> DsM (Core a)
1040 rep_splice splice_name
1041 = do { mb_val <- dsLookupMetaEnv splice_name
1042 ; case mb_val of
1043 Just (DsSplice e) -> do { e' <- dsExpr e
1044 ; return (MkC e') }
1045 _ -> pprPanic "HsSplice" (ppr splice_name) }
1046 -- Should not happen; statically checked
1047
1048 -----------------------------------------------------------------------------
1049 -- Expressions
1050 -----------------------------------------------------------------------------
1051
1052 repLEs :: [LHsExpr Name] -> DsM (Core [TH.ExpQ])
1053 repLEs es = repList expQTyConName repLE es
1054
1055 -- FIXME: some of these panics should be converted into proper error messages
1056 -- unless we can make sure that constructs, which are plainly not
1057 -- supported in TH already lead to error messages at an earlier stage
1058 repLE :: LHsExpr Name -> DsM (Core TH.ExpQ)
1059 repLE (L loc e) = putSrcSpanDs loc (repE e)
1060
1061 repE :: HsExpr Name -> DsM (Core TH.ExpQ)
1062 repE (HsVar (L _ x)) =
1063 do { mb_val <- dsLookupMetaEnv x
1064 ; case mb_val of
1065 Nothing -> do { str <- globalVar x
1066 ; repVarOrCon x str }
1067 Just (DsBound y) -> repVarOrCon x (coreVar y)
1068 Just (DsSplice e) -> do { e' <- dsExpr e
1069 ; return (MkC e') } }
1070 repE e@(HsIPVar _) = notHandled "Implicit parameters" (ppr e)
1071 repE e@(HsOverLabel _) = notHandled "Overloaded labels" (ppr e)
1072
1073 repE e@(HsRecFld f) = case f of
1074 Unambiguous _ x -> repE (HsVar (noLoc x))
1075 Ambiguous{} -> notHandled "Ambiguous record selectors" (ppr e)
1076
1077 -- Remember, we're desugaring renamer output here, so
1078 -- HsOverlit can definitely occur
1079 repE (HsOverLit l) = do { a <- repOverloadedLiteral l; repLit a }
1080 repE (HsLit l) = do { a <- repLiteral l; repLit a }
1081 repE (HsLam (MG { mg_alts = L _ [m] })) = repLambda m
1082 repE (HsLamCase _ (MG { mg_alts = L _ ms }))
1083 = do { ms' <- mapM repMatchTup ms
1084 ; core_ms <- coreList matchQTyConName ms'
1085 ; repLamCase core_ms }
1086 repE (HsApp x y) = do {a <- repLE x; b <- repLE y; repApp a b}
1087
1088 repE (OpApp e1 op _ e2) =
1089 do { arg1 <- repLE e1;
1090 arg2 <- repLE e2;
1091 the_op <- repLE op ;
1092 repInfixApp arg1 the_op arg2 }
1093 repE (NegApp x _) = do
1094 a <- repLE x
1095 negateVar <- lookupOcc negateName >>= repVar
1096 negateVar `repApp` a
1097 repE (HsPar x) = repLE x
1098 repE (SectionL x y) = do { a <- repLE x; b <- repLE y; repSectionL a b }
1099 repE (SectionR x y) = do { a <- repLE x; b <- repLE y; repSectionR a b }
1100 repE (HsCase e (MG { mg_alts = L _ ms }))
1101 = do { arg <- repLE e
1102 ; ms2 <- mapM repMatchTup ms
1103 ; core_ms2 <- coreList matchQTyConName ms2
1104 ; repCaseE arg core_ms2 }
1105 repE (HsIf _ x y z) = do
1106 a <- repLE x
1107 b <- repLE y
1108 c <- repLE z
1109 repCond a b c
1110 repE (HsMultiIf _ alts)
1111 = do { (binds, alts') <- liftM unzip $ mapM repLGRHS alts
1112 ; expr' <- repMultiIf (nonEmptyCoreList alts')
1113 ; wrapGenSyms (concat binds) expr' }
1114 repE (HsLet (L _ bs) e) = do { (ss,ds) <- repBinds bs
1115 ; e2 <- addBinds ss (repLE e)
1116 ; z <- repLetE ds e2
1117 ; wrapGenSyms ss z }
1118
1119 -- FIXME: I haven't got the types here right yet
1120 repE e@(HsDo ctxt (L _ sts) _)
1121 | case ctxt of { DoExpr -> True; GhciStmtCtxt -> True; _ -> False }
1122 = do { (ss,zs) <- repLSts sts;
1123 e' <- repDoE (nonEmptyCoreList zs);
1124 wrapGenSyms ss e' }
1125
1126 | ListComp <- ctxt
1127 = do { (ss,zs) <- repLSts sts;
1128 e' <- repComp (nonEmptyCoreList zs);
1129 wrapGenSyms ss e' }
1130
1131 | otherwise
1132 = notHandled "mdo, monad comprehension and [: :]" (ppr e)
1133
1134 repE (ExplicitList _ _ es) = do { xs <- repLEs es; repListExp xs }
1135 repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
1136 repE e@(ExplicitTuple es boxed)
1137 | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
1138 | isBoxed boxed = do { xs <- repLEs [e | L _ (Present e) <- es]; repTup xs }
1139 | otherwise = do { xs <- repLEs [e | L _ (Present e) <- es]
1140 ; repUnboxedTup xs }
1141
1142 repE (RecordCon { rcon_con_name = c, rcon_flds = flds })
1143 = do { x <- lookupLOcc c;
1144 fs <- repFields flds;
1145 repRecCon x fs }
1146 repE (RecordUpd { rupd_expr = e, rupd_flds = flds })
1147 = do { x <- repLE e;
1148 fs <- repUpdFields flds;
1149 repRecUpd x fs }
1150
1151 repE (ExprWithTySig e ty)
1152 = do { e1 <- repLE e
1153 ; t1 <- repHsSigWcType ty
1154 ; repSigExp e1 t1 }
1155
1156 repE (ArithSeq _ _ aseq) =
1157 case aseq of
1158 From e -> do { ds1 <- repLE e; repFrom ds1 }
1159 FromThen e1 e2 -> do
1160 ds1 <- repLE e1
1161 ds2 <- repLE e2
1162 repFromThen ds1 ds2
1163 FromTo e1 e2 -> do
1164 ds1 <- repLE e1
1165 ds2 <- repLE e2
1166 repFromTo ds1 ds2
1167 FromThenTo e1 e2 e3 -> do
1168 ds1 <- repLE e1
1169 ds2 <- repLE e2
1170 ds3 <- repLE e3
1171 repFromThenTo ds1 ds2 ds3
1172
1173 repE (HsSpliceE splice) = repSplice splice
1174 repE (HsStatic e) = repLE e >>= rep2 staticEName . (:[]) . unC
1175 repE (HsUnboundVar name) = do
1176 occ <- occNameLit name
1177 sname <- repNameS occ
1178 repUnboundVar sname
1179
1180 repE e@(PArrSeq {}) = notHandled "Parallel arrays" (ppr e)
1181 repE e@(HsCoreAnn {}) = notHandled "Core annotations" (ppr e)
1182 repE e@(HsSCC {}) = notHandled "Cost centres" (ppr e)
1183 repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
1184 repE e@(HsTcBracketOut {}) = notHandled "TH brackets" (ppr e)
1185 repE e = notHandled "Expression form" (ppr e)
1186
1187 -----------------------------------------------------------------------------
1188 -- Building representations of auxillary structures like Match, Clause, Stmt,
1189
1190 repMatchTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.MatchQ)
1191 repMatchTup (L _ (Match _ [p] _ (GRHSs guards (L _ wheres)))) =
1192 do { ss1 <- mkGenSyms (collectPatBinders p)
1193 ; addBinds ss1 $ do {
1194 ; p1 <- repLP p
1195 ; (ss2,ds) <- repBinds wheres
1196 ; addBinds ss2 $ do {
1197 ; gs <- repGuards guards
1198 ; match <- repMatch p1 gs ds
1199 ; wrapGenSyms (ss1++ss2) match }}}
1200 repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
1201
1202 repClauseTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ClauseQ)
1203 repClauseTup (L _ (Match _ ps _ (GRHSs guards (L _ wheres)))) =
1204 do { ss1 <- mkGenSyms (collectPatsBinders ps)
1205 ; addBinds ss1 $ do {
1206 ps1 <- repLPs ps
1207 ; (ss2,ds) <- repBinds wheres
1208 ; addBinds ss2 $ do {
1209 gs <- repGuards guards
1210 ; clause <- repClause ps1 gs ds
1211 ; wrapGenSyms (ss1++ss2) clause }}}
1212
1213 repGuards :: [LGRHS Name (LHsExpr Name)] -> DsM (Core TH.BodyQ)
1214 repGuards [L _ (GRHS [] e)]
1215 = do {a <- repLE e; repNormal a }
1216 repGuards other
1217 = do { zs <- mapM repLGRHS other
1218 ; let (xs, ys) = unzip zs
1219 ; gd <- repGuarded (nonEmptyCoreList ys)
1220 ; wrapGenSyms (concat xs) gd }
1221
1222 repLGRHS :: LGRHS Name (LHsExpr Name) -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
1223 repLGRHS (L _ (GRHS [L _ (BodyStmt e1 _ _ _)] e2))
1224 = do { guarded <- repLNormalGE e1 e2
1225 ; return ([], guarded) }
1226 repLGRHS (L _ (GRHS ss rhs))
1227 = do { (gs, ss') <- repLSts ss
1228 ; rhs' <- addBinds gs $ repLE rhs
1229 ; guarded <- repPatGE (nonEmptyCoreList ss') rhs'
1230 ; return (gs, guarded) }
1231
1232 repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
1233 repFields (HsRecFields { rec_flds = flds })
1234 = repList fieldExpQTyConName rep_fld flds
1235 where
1236 rep_fld :: LHsRecField Name (LHsExpr Name) -> DsM (Core (TH.Q TH.FieldExp))
1237 rep_fld (L _ fld) = do { fn <- lookupLOcc (hsRecFieldSel fld)
1238 ; e <- repLE (hsRecFieldArg fld)
1239 ; repFieldExp fn e }
1240
1241 repUpdFields :: [LHsRecUpdField Name] -> DsM (Core [TH.Q TH.FieldExp])
1242 repUpdFields = repList fieldExpQTyConName rep_fld
1243 where
1244 rep_fld :: LHsRecUpdField Name -> DsM (Core (TH.Q TH.FieldExp))
1245 rep_fld (L l fld) = case unLoc (hsRecFieldLbl fld) of
1246 Unambiguous _ sel_name -> do { fn <- lookupLOcc (L l sel_name)
1247 ; e <- repLE (hsRecFieldArg fld)
1248 ; repFieldExp fn e }
1249 _ -> notHandled "Ambiguous record updates" (ppr fld)
1250
1251
1252
1253 -----------------------------------------------------------------------------
1254 -- Representing Stmt's is tricky, especially if bound variables
1255 -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |]
1256 -- First gensym new names for every variable in any of the patterns.
1257 -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
1258 -- if variables didn't shaddow, the static gensym wouldn't be necessary
1259 -- and we could reuse the original names (x and x).
1260 --
1261 -- do { x'1 <- gensym "x"
1262 -- ; x'2 <- gensym "x"
1263 -- ; doE [ BindSt (pvar x'1) [| f 1 |]
1264 -- , BindSt (pvar x'2) [| f x |]
1265 -- , NoBindSt [| g x |]
1266 -- ]
1267 -- }
1268
1269 -- The strategy is to translate a whole list of do-bindings by building a
1270 -- bigger environment, and a bigger set of meta bindings
1271 -- (like: x'1 <- gensym "x" ) and then combining these with the translations
1272 -- of the expressions within the Do
1273
1274 -----------------------------------------------------------------------------
1275 -- The helper function repSts computes the translation of each sub expression
1276 -- and a bunch of prefix bindings denoting the dynamic renaming.
1277
1278 repLSts :: [LStmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1279 repLSts stmts = repSts (map unLoc stmts)
1280
1281 repSts :: [Stmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1282 repSts (BindStmt p e _ _ _ : ss) =
1283 do { e2 <- repLE e
1284 ; ss1 <- mkGenSyms (collectPatBinders p)
1285 ; addBinds ss1 $ do {
1286 ; p1 <- repLP p;
1287 ; (ss2,zs) <- repSts ss
1288 ; z <- repBindSt p1 e2
1289 ; return (ss1++ss2, z : zs) }}
1290 repSts (LetStmt (L _ bs) : ss) =
1291 do { (ss1,ds) <- repBinds bs
1292 ; z <- repLetSt ds
1293 ; (ss2,zs) <- addBinds ss1 (repSts ss)
1294 ; return (ss1++ss2, z : zs) }
1295 repSts (BodyStmt e _ _ _ : ss) =
1296 do { e2 <- repLE e
1297 ; z <- repNoBindSt e2
1298 ; (ss2,zs) <- repSts ss
1299 ; return (ss2, z : zs) }
1300 repSts (ParStmt stmt_blocks _ _ _ : ss) =
1301 do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks
1302 ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1
1303 ss1 = concat ss_s
1304 ; z <- repParSt stmt_blocks2
1305 ; (ss2, zs) <- addBinds ss1 (repSts ss)
1306 ; return (ss1++ss2, z : zs) }
1307 where
1308 rep_stmt_block :: ParStmtBlock Name Name -> DsM ([GenSymBind], Core [TH.StmtQ])
1309 rep_stmt_block (ParStmtBlock stmts _ _) =
1310 do { (ss1, zs) <- repSts (map unLoc stmts)
1311 ; zs1 <- coreList stmtQTyConName zs
1312 ; return (ss1, zs1) }
1313 repSts [LastStmt e _ _]
1314 = do { e2 <- repLE e
1315 ; z <- repNoBindSt e2
1316 ; return ([], [z]) }
1317 repSts [] = return ([],[])
1318 repSts other = notHandled "Exotic statement" (ppr other)
1319
1320
1321 -----------------------------------------------------------
1322 -- Bindings
1323 -----------------------------------------------------------
1324
1325 repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ])
1326 repBinds EmptyLocalBinds
1327 = do { core_list <- coreList decQTyConName []
1328 ; return ([], core_list) }
1329
1330 repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
1331
1332 repBinds (HsValBinds decs)
1333 = do { let { bndrs = hsSigTvBinders decs ++ collectHsValBinders decs }
1334 -- No need to worrry about detailed scopes within
1335 -- the binding group, because we are talking Names
1336 -- here, so we can safely treat it as a mutually
1337 -- recursive group
1338 -- For hsSigTvBinders see Note [Scoped type variables in bindings]
1339 ; ss <- mkGenSyms bndrs
1340 ; prs <- addBinds ss (rep_val_binds decs)
1341 ; core_list <- coreList decQTyConName
1342 (de_loc (sort_by_loc prs))
1343 ; return (ss, core_list) }
1344
1345 rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1346 -- Assumes: all the binders of the binding are alrady in the meta-env
1347 rep_val_binds (ValBindsOut binds sigs)
1348 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
1349 ; core2 <- rep_sigs' sigs
1350 ; return (core1 ++ core2) }
1351 rep_val_binds (ValBindsIn _ _)
1352 = panic "rep_val_binds: ValBindsIn"
1353
1354 rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
1355 rep_binds binds = do { binds_w_locs <- rep_binds' binds
1356 ; return (de_loc (sort_by_loc binds_w_locs)) }
1357
1358 rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1359 rep_binds' = mapM rep_bind . bagToList
1360
1361 rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
1362 -- Assumes: all the binders of the binding are alrady in the meta-env
1363
1364 -- Note GHC treats declarations of a variable (not a pattern)
1365 -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match
1366 -- with an empty list of patterns
1367 rep_bind (L loc (FunBind
1368 { fun_id = fn,
1369 fun_matches = MG { mg_alts
1370 = L _ [L _ (Match _ [] _
1371 (GRHSs guards (L _ wheres)))] } }))
1372 = do { (ss,wherecore) <- repBinds wheres
1373 ; guardcore <- addBinds ss (repGuards guards)
1374 ; fn' <- lookupLBinder fn
1375 ; p <- repPvar fn'
1376 ; ans <- repVal p guardcore wherecore
1377 ; ans' <- wrapGenSyms ss ans
1378 ; return (loc, ans') }
1379
1380 rep_bind (L loc (FunBind { fun_id = fn
1381 , fun_matches = MG { mg_alts = L _ ms } }))
1382 = do { ms1 <- mapM repClauseTup ms
1383 ; fn' <- lookupLBinder fn
1384 ; ans <- repFun fn' (nonEmptyCoreList ms1)
1385 ; return (loc, ans) }
1386
1387 rep_bind (L loc (PatBind { pat_lhs = pat
1388 , pat_rhs = GRHSs guards (L _ wheres) }))
1389 = do { patcore <- repLP pat
1390 ; (ss,wherecore) <- repBinds wheres
1391 ; guardcore <- addBinds ss (repGuards guards)
1392 ; ans <- repVal patcore guardcore wherecore
1393 ; ans' <- wrapGenSyms ss ans
1394 ; return (loc, ans') }
1395
1396 rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1397 = do { v' <- lookupBinder v
1398 ; e2 <- repLE e
1399 ; x <- repNormal e2
1400 ; patcore <- repPvar v'
1401 ; empty_decls <- coreList decQTyConName []
1402 ; ans <- repVal patcore x empty_decls
1403 ; return (srcLocSpan (getSrcLoc v), ans) }
1404
1405 rep_bind (L _ (AbsBinds {})) = panic "rep_bind: AbsBinds"
1406 rep_bind (L _ (AbsBindsSig {})) = panic "rep_bind: AbsBindsSig"
1407 rep_bind (L _ dec@(PatSynBind {})) = notHandled "pattern synonyms" (ppr dec)
1408 -----------------------------------------------------------------------------
1409 -- Since everything in a Bind is mutually recursive we need rename all
1410 -- all the variables simultaneously. For example:
1411 -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to
1412 -- do { f'1 <- gensym "f"
1413 -- ; g'2 <- gensym "g"
1414 -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]},
1415 -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]}
1416 -- ]}
1417 -- This requires collecting the bindings (f'1 <- gensym "f"), and the
1418 -- environment ( f |-> f'1 ) from each binding, and then unioning them
1419 -- together. As we do this we collect GenSymBinds's which represent the renamed
1420 -- variables bound by the Bindings. In order not to lose track of these
1421 -- representations we build a shadow datatype MB with the same structure as
1422 -- MonoBinds, but which has slots for the representations
1423
1424
1425 -----------------------------------------------------------------------------
1426 -- GHC allows a more general form of lambda abstraction than specified
1427 -- by Haskell 98. In particular it allows guarded lambda's like :
1428 -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in
1429 -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like
1430 -- (\ p1 .. pn -> exp) by causing an error.
1431
1432 repLambda :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ExpQ)
1433 repLambda (L _ (Match _ ps _ (GRHSs [L _ (GRHS [] e)] (L _ EmptyLocalBinds))))
1434 = do { let bndrs = collectPatsBinders ps ;
1435 ; ss <- mkGenSyms bndrs
1436 ; lam <- addBinds ss (
1437 do { xs <- repLPs ps; body <- repLE e; repLam xs body })
1438 ; wrapGenSyms ss lam }
1439
1440 repLambda (L _ m) = notHandled "Guarded labmdas" (pprMatch (LambdaExpr :: HsMatchContext Name) m)
1441
1442
1443 -----------------------------------------------------------------------------
1444 -- Patterns
1445 -- repP deals with patterns. It assumes that we have already
1446 -- walked over the pattern(s) once to collect the binders, and
1447 -- have extended the environment. So every pattern-bound
1448 -- variable should already appear in the environment.
1449
1450 -- Process a list of patterns
1451 repLPs :: [LPat Name] -> DsM (Core [TH.PatQ])
1452 repLPs ps = repList patQTyConName repLP ps
1453
1454 repLP :: LPat Name -> DsM (Core TH.PatQ)
1455 repLP (L _ p) = repP p
1456
1457 repP :: Pat Name -> DsM (Core TH.PatQ)
1458 repP (WildPat _) = repPwild
1459 repP (LitPat l) = do { l2 <- repLiteral l; repPlit l2 }
1460 repP (VarPat (L _ x)) = do { x' <- lookupBinder x; repPvar x' }
1461 repP (LazyPat p) = do { p1 <- repLP p; repPtilde p1 }
1462 repP (BangPat p) = do { p1 <- repLP p; repPbang p1 }
1463 repP (AsPat x p) = do { x' <- lookupLBinder x; p1 <- repLP p; repPaspat x' p1 }
1464 repP (ParPat p) = repLP p
1465 repP (ListPat ps _ Nothing) = do { qs <- repLPs ps; repPlist qs }
1466 repP (ListPat ps ty1 (Just (_,e))) = do { p <- repP (ListPat ps ty1 Nothing); e' <- repE (syn_expr e); repPview e' p}
1467 repP (TuplePat ps boxed _)
1468 | isBoxed boxed = do { qs <- repLPs ps; repPtup qs }
1469 | otherwise = do { qs <- repLPs ps; repPunboxedTup qs }
1470 repP (ConPatIn dc details)
1471 = do { con_str <- lookupLOcc dc
1472 ; case details of
1473 PrefixCon ps -> do { qs <- repLPs ps; repPcon con_str qs }
1474 RecCon rec -> do { fps <- repList fieldPatQTyConName rep_fld (rec_flds rec)
1475 ; repPrec con_str fps }
1476 InfixCon p1 p2 -> do { p1' <- repLP p1;
1477 p2' <- repLP p2;
1478 repPinfix p1' con_str p2' }
1479 }
1480 where
1481 rep_fld :: LHsRecField Name (LPat Name) -> DsM (Core (TH.Name,TH.PatQ))
1482 rep_fld (L _ fld) = do { MkC v <- lookupLOcc (hsRecFieldSel fld)
1483 ; MkC p <- repLP (hsRecFieldArg fld)
1484 ; rep2 fieldPatName [v,p] }
1485
1486 repP (NPat (L _ l) Nothing _ _) = do { a <- repOverloadedLiteral l; repPlit a }
1487 repP (ViewPat e p _) = do { e' <- repLE e; p' <- repLP p; repPview e' p' }
1488 repP p@(NPat _ (Just _) _ _) = notHandled "Negative overloaded patterns" (ppr p)
1489 repP p@(SigPatIn {}) = notHandled "Type signatures in patterns" (ppr p)
1490 -- The problem is to do with scoped type variables.
1491 -- To implement them, we have to implement the scoping rules
1492 -- here in DsMeta, and I don't want to do that today!
1493 -- do { p' <- repLP p; t' <- repLTy t; repPsig p' t' }
1494 -- repPsig :: Core TH.PatQ -> Core TH.TypeQ -> DsM (Core TH.PatQ)
1495 -- repPsig (MkC p) (MkC t) = rep2 sigPName [p, t]
1496
1497 repP (SplicePat splice) = repSplice splice
1498
1499 repP other = notHandled "Exotic pattern" (ppr other)
1500
1501 ----------------------------------------------------------
1502 -- Declaration ordering helpers
1503
1504 sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)]
1505 sort_by_loc xs = sortBy comp xs
1506 where comp x y = compare (fst x) (fst y)
1507
1508 de_loc :: [(a, b)] -> [b]
1509 de_loc = map snd
1510
1511 ----------------------------------------------------------
1512 -- The meta-environment
1513
1514 -- A name/identifier association for fresh names of locally bound entities
1515 type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id
1516 -- I.e. (x, x_id) means
1517 -- let x_id = gensym "x" in ...
1518
1519 -- Generate a fresh name for a locally bound entity
1520
1521 mkGenSyms :: [Name] -> DsM [GenSymBind]
1522 -- We can use the existing name. For example:
1523 -- [| \x_77 -> x_77 + x_77 |]
1524 -- desugars to
1525 -- do { x_77 <- genSym "x"; .... }
1526 -- We use the same x_77 in the desugared program, but with the type Bndr
1527 -- instead of Int
1528 --
1529 -- We do make it an Internal name, though (hence localiseName)
1530 --
1531 -- Nevertheless, it's monadic because we have to generate nameTy
1532 mkGenSyms ns = do { var_ty <- lookupType nameTyConName
1533 ; return [(nm, mkLocalId (localiseName nm) var_ty) | nm <- ns] }
1534
1535
1536 addBinds :: [GenSymBind] -> DsM a -> DsM a
1537 -- Add a list of fresh names for locally bound entities to the
1538 -- meta environment (which is part of the state carried around
1539 -- by the desugarer monad)
1540 addBinds bs m = dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs]) m
1541
1542 -- Look up a locally bound name
1543 --
1544 lookupLBinder :: Located Name -> DsM (Core TH.Name)
1545 lookupLBinder (L _ n) = lookupBinder n
1546
1547 lookupBinder :: Name -> DsM (Core TH.Name)
1548 lookupBinder = lookupOcc
1549 -- Binders are brought into scope before the pattern or what-not is
1550 -- desugared. Moreover, in instance declaration the binder of a method
1551 -- will be the selector Id and hence a global; so we need the
1552 -- globalVar case of lookupOcc
1553
1554 -- Look up a name that is either locally bound or a global name
1555 --
1556 -- * If it is a global name, generate the "original name" representation (ie,
1557 -- the <module>:<name> form) for the associated entity
1558 --
1559 lookupLOcc :: Located Name -> DsM (Core TH.Name)
1560 -- Lookup an occurrence; it can't be a splice.
1561 -- Use the in-scope bindings if they exist
1562 lookupLOcc (L _ n) = lookupOcc n
1563
1564 lookupOcc :: Name -> DsM (Core TH.Name)
1565 lookupOcc n
1566 = do { mb_val <- dsLookupMetaEnv n ;
1567 case mb_val of
1568 Nothing -> globalVar n
1569 Just (DsBound x) -> return (coreVar x)
1570 Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n)
1571 }
1572
1573 globalVar :: Name -> DsM (Core TH.Name)
1574 -- Not bound by the meta-env
1575 -- Could be top-level; or could be local
1576 -- f x = $(g [| x |])
1577 -- Here the x will be local
1578 globalVar name
1579 | isExternalName name
1580 = do { MkC mod <- coreStringLit name_mod
1581 ; MkC pkg <- coreStringLit name_pkg
1582 ; MkC occ <- nameLit name
1583 ; rep2 mk_varg [pkg,mod,occ] }
1584 | otherwise
1585 = do { MkC occ <- nameLit name
1586 ; MkC uni <- coreIntLit (getKey (getUnique name))
1587 ; rep2 mkNameLName [occ,uni] }
1588 where
1589 mod = ASSERT( isExternalName name) nameModule name
1590 name_mod = moduleNameString (moduleName mod)
1591 name_pkg = unitIdString (moduleUnitId mod)
1592 name_occ = nameOccName name
1593 mk_varg | OccName.isDataOcc name_occ = mkNameG_dName
1594 | OccName.isVarOcc name_occ = mkNameG_vName
1595 | OccName.isTcOcc name_occ = mkNameG_tcName
1596 | otherwise = pprPanic "DsMeta.globalVar" (ppr name)
1597
1598 lookupType :: Name -- Name of type constructor (e.g. TH.ExpQ)
1599 -> DsM Type -- The type
1600 lookupType tc_name = do { tc <- dsLookupTyCon tc_name ;
1601 return (mkTyConApp tc []) }
1602
1603 wrapGenSyms :: [GenSymBind]
1604 -> Core (TH.Q a) -> DsM (Core (TH.Q a))
1605 -- wrapGenSyms [(nm1,id1), (nm2,id2)] y
1606 -- --> bindQ (gensym nm1) (\ id1 ->
1607 -- bindQ (gensym nm2 (\ id2 ->
1608 -- y))
1609
1610 wrapGenSyms binds body@(MkC b)
1611 = do { var_ty <- lookupType nameTyConName
1612 ; go var_ty binds }
1613 where
1614 [elt_ty] = tcTyConAppArgs (exprType b)
1615 -- b :: Q a, so we can get the type 'a' by looking at the
1616 -- argument type. NB: this relies on Q being a data/newtype,
1617 -- not a type synonym
1618
1619 go _ [] = return body
1620 go var_ty ((name,id) : binds)
1621 = do { MkC body' <- go var_ty binds
1622 ; lit_str <- nameLit name
1623 ; gensym_app <- repGensym lit_str
1624 ; repBindQ var_ty elt_ty
1625 gensym_app (MkC (Lam id body')) }
1626
1627 nameLit :: Name -> DsM (Core String)
1628 nameLit n = coreStringLit (occNameString (nameOccName n))
1629
1630 occNameLit :: OccName -> DsM (Core String)
1631 occNameLit name = coreStringLit (occNameString name)
1632
1633
1634 -- %*********************************************************************
1635 -- %* *
1636 -- Constructing code
1637 -- %* *
1638 -- %*********************************************************************
1639
1640 -----------------------------------------------------------------------------
1641 -- PHANTOM TYPES for consistency. In order to make sure we do this correct
1642 -- we invent a new datatype which uses phantom types.
1643
1644 newtype Core a = MkC CoreExpr
1645 unC :: Core a -> CoreExpr
1646 unC (MkC x) = x
1647
1648 rep2 :: Name -> [ CoreExpr ] -> DsM (Core a)
1649 rep2 n xs = do { id <- dsLookupGlobalId n
1650 ; return (MkC (foldl App (Var id) xs)) }
1651
1652 dataCon' :: Name -> [CoreExpr] -> DsM (Core a)
1653 dataCon' n args = do { id <- dsLookupDataCon n
1654 ; return $ MkC $ mkCoreConApps id args }
1655
1656 dataCon :: Name -> DsM (Core a)
1657 dataCon n = dataCon' n []
1658
1659
1660 -- %*********************************************************************
1661 -- %* *
1662 -- The 'smart constructors'
1663 -- %* *
1664 -- %*********************************************************************
1665
1666 --------------- Patterns -----------------
1667 repPlit :: Core TH.Lit -> DsM (Core TH.PatQ)
1668 repPlit (MkC l) = rep2 litPName [l]
1669
1670 repPvar :: Core TH.Name -> DsM (Core TH.PatQ)
1671 repPvar (MkC s) = rep2 varPName [s]
1672
1673 repPtup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1674 repPtup (MkC ps) = rep2 tupPName [ps]
1675
1676 repPunboxedTup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1677 repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps]
1678
1679 repPcon :: Core TH.Name -> Core [TH.PatQ] -> DsM (Core TH.PatQ)
1680 repPcon (MkC s) (MkC ps) = rep2 conPName [s, ps]
1681
1682 repPrec :: Core TH.Name -> Core [(TH.Name,TH.PatQ)] -> DsM (Core TH.PatQ)
1683 repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps]
1684
1685 repPinfix :: Core TH.PatQ -> Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1686 repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2]
1687
1688 repPtilde :: Core TH.PatQ -> DsM (Core TH.PatQ)
1689 repPtilde (MkC p) = rep2 tildePName [p]
1690
1691 repPbang :: Core TH.PatQ -> DsM (Core TH.PatQ)
1692 repPbang (MkC p) = rep2 bangPName [p]
1693
1694 repPaspat :: Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1695 repPaspat (MkC s) (MkC p) = rep2 asPName [s, p]
1696
1697 repPwild :: DsM (Core TH.PatQ)
1698 repPwild = rep2 wildPName []
1699
1700 repPlist :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1701 repPlist (MkC ps) = rep2 listPName [ps]
1702
1703 repPview :: Core TH.ExpQ -> Core TH.PatQ -> DsM (Core TH.PatQ)
1704 repPview (MkC e) (MkC p) = rep2 viewPName [e,p]
1705
1706 --------------- Expressions -----------------
1707 repVarOrCon :: Name -> Core TH.Name -> DsM (Core TH.ExpQ)
1708 repVarOrCon vc str | isDataOcc (nameOccName vc) = repCon str
1709 | otherwise = repVar str
1710
1711 repVar :: Core TH.Name -> DsM (Core TH.ExpQ)
1712 repVar (MkC s) = rep2 varEName [s]
1713
1714 repCon :: Core TH.Name -> DsM (Core TH.ExpQ)
1715 repCon (MkC s) = rep2 conEName [s]
1716
1717 repLit :: Core TH.Lit -> DsM (Core TH.ExpQ)
1718 repLit (MkC c) = rep2 litEName [c]
1719
1720 repApp :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1721 repApp (MkC x) (MkC y) = rep2 appEName [x,y]
1722
1723 repLam :: Core [TH.PatQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1724 repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e]
1725
1726 repLamCase :: Core [TH.MatchQ] -> DsM (Core TH.ExpQ)
1727 repLamCase (MkC ms) = rep2 lamCaseEName [ms]
1728
1729 repTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1730 repTup (MkC es) = rep2 tupEName [es]
1731
1732 repUnboxedTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1733 repUnboxedTup (MkC es) = rep2 unboxedTupEName [es]
1734
1735 repCond :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1736 repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z]
1737
1738 repMultiIf :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.ExpQ)
1739 repMultiIf (MkC alts) = rep2 multiIfEName [alts]
1740
1741 repLetE :: Core [TH.DecQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1742 repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e]
1743
1744 repCaseE :: Core TH.ExpQ -> Core [TH.MatchQ] -> DsM( Core TH.ExpQ)
1745 repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms]
1746
1747 repDoE :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1748 repDoE (MkC ss) = rep2 doEName [ss]
1749
1750 repComp :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1751 repComp (MkC ss) = rep2 compEName [ss]
1752
1753 repListExp :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1754 repListExp (MkC es) = rep2 listEName [es]
1755
1756 repSigExp :: Core TH.ExpQ -> Core TH.TypeQ -> DsM (Core TH.ExpQ)
1757 repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t]
1758
1759 repRecCon :: Core TH.Name -> Core [TH.Q TH.FieldExp]-> DsM (Core TH.ExpQ)
1760 repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs]
1761
1762 repRecUpd :: Core TH.ExpQ -> Core [TH.Q TH.FieldExp] -> DsM (Core TH.ExpQ)
1763 repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs]
1764
1765 repFieldExp :: Core TH.Name -> Core TH.ExpQ -> DsM (Core (TH.Q TH.FieldExp))
1766 repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x]
1767
1768 repInfixApp :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1769 repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z]
1770
1771 repSectionL :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1772 repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y]
1773
1774 repSectionR :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1775 repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y]
1776
1777 ------------ Right hand sides (guarded expressions) ----
1778 repGuarded :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.BodyQ)
1779 repGuarded (MkC pairs) = rep2 guardedBName [pairs]
1780
1781 repNormal :: Core TH.ExpQ -> DsM (Core TH.BodyQ)
1782 repNormal (MkC e) = rep2 normalBName [e]
1783
1784 ------------ Guards ----
1785 repLNormalGE :: LHsExpr Name -> LHsExpr Name -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1786 repLNormalGE g e = do g' <- repLE g
1787 e' <- repLE e
1788 repNormalGE g' e'
1789
1790 repNormalGE :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1791 repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e]
1792
1793 repPatGE :: Core [TH.StmtQ] -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1794 repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e]
1795
1796 ------------- Stmts -------------------
1797 repBindSt :: Core TH.PatQ -> Core TH.ExpQ -> DsM (Core TH.StmtQ)
1798 repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e]
1799
1800 repLetSt :: Core [TH.DecQ] -> DsM (Core TH.StmtQ)
1801 repLetSt (MkC ds) = rep2 letSName [ds]
1802
1803 repNoBindSt :: Core TH.ExpQ -> DsM (Core TH.StmtQ)
1804 repNoBindSt (MkC e) = rep2 noBindSName [e]
1805
1806 repParSt :: Core [[TH.StmtQ]] -> DsM (Core TH.StmtQ)
1807 repParSt (MkC sss) = rep2 parSName [sss]
1808
1809 -------------- Range (Arithmetic sequences) -----------
1810 repFrom :: Core TH.ExpQ -> DsM (Core TH.ExpQ)
1811 repFrom (MkC x) = rep2 fromEName [x]
1812
1813 repFromThen :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1814 repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y]
1815
1816 repFromTo :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1817 repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y]
1818
1819 repFromThenTo :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1820 repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z]
1821
1822 ------------ Match and Clause Tuples -----------
1823 repMatch :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.MatchQ)
1824 repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds]
1825
1826 repClause :: Core [TH.PatQ] -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.ClauseQ)
1827 repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds]
1828
1829 -------------- Dec -----------------------------
1830 repVal :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1831 repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds]
1832
1833 repFun :: Core TH.Name -> Core [TH.ClauseQ] -> DsM (Core TH.DecQ)
1834 repFun (MkC nm) (MkC b) = rep2 funDName [nm, b]
1835
1836 repData :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1837 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1838 -> Core [TH.ConQ] -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1839 repData (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC cons) (MkC derivs)
1840 = rep2 dataDName [cxt, nm, tvs, ksig, cons, derivs]
1841 repData (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC cons)
1842 (MkC derivs)
1843 = rep2 dataInstDName [cxt, nm, tys, ksig, cons, derivs]
1844
1845 repNewtype :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1846 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1847 -> Core TH.ConQ -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1848 repNewtype (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC con)
1849 (MkC derivs)
1850 = rep2 newtypeDName [cxt, nm, tvs, ksig, con, derivs]
1851 repNewtype (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC con)
1852 (MkC derivs)
1853 = rep2 newtypeInstDName [cxt, nm, tys, ksig, con, derivs]
1854
1855 repTySyn :: Core TH.Name -> Core [TH.TyVarBndr]
1856 -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1857 repTySyn (MkC nm) (MkC tvs) (MkC rhs)
1858 = rep2 tySynDName [nm, tvs, rhs]
1859
1860 repInst :: Core TH.CxtQ -> Core TH.TypeQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1861 repInst (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceDName [cxt, ty, ds]
1862
1863 repClass :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1864 -> Core [TH.FunDep] -> Core [TH.DecQ]
1865 -> DsM (Core TH.DecQ)
1866 repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds)
1867 = rep2 classDName [cxt, cls, tvs, fds, ds]
1868
1869 repDeriv :: Core TH.CxtQ -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1870 repDeriv (MkC cxt) (MkC ty) = rep2 standaloneDerivDName [cxt, ty]
1871
1872 repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch
1873 -> Core TH.Phases -> DsM (Core TH.DecQ)
1874 repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases)
1875 = rep2 pragInlDName [nm, inline, rm, phases]
1876
1877 repPragSpec :: Core TH.Name -> Core TH.TypeQ -> Core TH.Phases
1878 -> DsM (Core TH.DecQ)
1879 repPragSpec (MkC nm) (MkC ty) (MkC phases)
1880 = rep2 pragSpecDName [nm, ty, phases]
1881
1882 repPragSpecInl :: Core TH.Name -> Core TH.TypeQ -> Core TH.Inline
1883 -> Core TH.Phases -> DsM (Core TH.DecQ)
1884 repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases)
1885 = rep2 pragSpecInlDName [nm, ty, inline, phases]
1886
1887 repPragSpecInst :: Core TH.TypeQ -> DsM (Core TH.DecQ)
1888 repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty]
1889
1890 repPragRule :: Core String -> Core [TH.RuleBndrQ] -> Core TH.ExpQ
1891 -> Core TH.ExpQ -> Core TH.Phases -> DsM (Core TH.DecQ)
1892 repPragRule (MkC nm) (MkC bndrs) (MkC lhs) (MkC rhs) (MkC phases)
1893 = rep2 pragRuleDName [nm, bndrs, lhs, rhs, phases]
1894
1895 repPragAnn :: Core TH.AnnTarget -> Core TH.ExpQ -> DsM (Core TH.DecQ)
1896 repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e]
1897
1898 repTySynInst :: Core TH.Name -> Core TH.TySynEqnQ -> DsM (Core TH.DecQ)
1899 repTySynInst (MkC nm) (MkC eqn)
1900 = rep2 tySynInstDName [nm, eqn]
1901
1902 repDataFamilyD :: Core TH.Name -> Core [TH.TyVarBndr]
1903 -> Core (Maybe TH.Kind) -> DsM (Core TH.DecQ)
1904 repDataFamilyD (MkC nm) (MkC tvs) (MkC kind)
1905 = rep2 dataFamilyDName [nm, tvs, kind]
1906
1907 repOpenFamilyD :: Core TH.Name
1908 -> Core [TH.TyVarBndr]
1909 -> Core TH.FamilyResultSig
1910 -> Core (Maybe TH.InjectivityAnn)
1911 -> DsM (Core TH.DecQ)
1912 repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj)
1913 = rep2 openTypeFamilyDName [nm, tvs, result, inj]
1914
1915 repClosedFamilyD :: Core TH.Name
1916 -> Core [TH.TyVarBndr]
1917 -> Core TH.FamilyResultSig
1918 -> Core (Maybe TH.InjectivityAnn)
1919 -> Core [TH.TySynEqnQ]
1920 -> DsM (Core TH.DecQ)
1921 repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns)
1922 = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns]
1923
1924 repTySynEqn :: Core [TH.TypeQ] -> Core TH.TypeQ -> DsM (Core TH.TySynEqnQ)
1925 repTySynEqn (MkC lhs) (MkC rhs)
1926 = rep2 tySynEqnName [lhs, rhs]
1927
1928 repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> DsM (Core TH.DecQ)
1929 repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles]
1930
1931 repFunDep :: Core [TH.Name] -> Core [TH.Name] -> DsM (Core TH.FunDep)
1932 repFunDep (MkC xs) (MkC ys) = rep2 funDepName [xs, ys]
1933
1934 repProto :: Name -> Core TH.Name -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1935 repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty]
1936
1937 repCtxt :: Core [TH.PredQ] -> DsM (Core TH.CxtQ)
1938 repCtxt (MkC tys) = rep2 cxtName [tys]
1939
1940 repDataCon :: Located Name
1941 -> HsConDeclDetails Name
1942 -> DsM (Core TH.ConQ)
1943 repDataCon con details
1944 = do con' <- lookupLOcc con -- See Note [Binders and occurrences]
1945 repConstr details Nothing [con']
1946
1947 repGadtDataCons :: [Located Name]
1948 -> HsConDeclDetails Name
1949 -> LHsType Name
1950 -> DsM (Core TH.ConQ)
1951 repGadtDataCons cons details res_ty
1952 = do cons' <- mapM lookupLOcc cons -- See Note [Binders and occurrences]
1953 repConstr details (Just res_ty) cons'
1954
1955 -- Invariant:
1956 -- * for plain H98 data constructors second argument is Nothing and third
1957 -- argument is a singleton list
1958 -- * for GADTs data constructors second argument is (Just return_type) and
1959 -- third argument is a non-empty list
1960 repConstr :: HsConDeclDetails Name
1961 -> Maybe (LHsType Name)
1962 -> [Core TH.Name]
1963 -> DsM (Core TH.ConQ)
1964 repConstr (PrefixCon ps) Nothing [con]
1965 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
1966 rep2 normalCName [unC con, unC arg_tys]
1967
1968 repConstr (PrefixCon ps) (Just (L _ res_ty)) cons
1969 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
1970 res_ty' <- repTy res_ty
1971 rep2 gadtCName [ unC (nonEmptyCoreList cons), unC arg_tys, unC res_ty']
1972
1973 repConstr (RecCon (L _ ips)) resTy cons
1974 = do args <- concatMapM rep_ip ips
1975 arg_vtys <- coreList varBangTypeQTyConName args
1976 case resTy of
1977 Nothing -> rep2 recCName [unC (head cons), unC arg_vtys]
1978 Just (L _ res_ty) -> do
1979 res_ty' <- repTy res_ty
1980 rep2 recGadtCName [unC (nonEmptyCoreList cons), unC arg_vtys,
1981 unC res_ty']
1982
1983 where
1984 rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip)
1985
1986 rep_one_ip :: LBangType Name -> LFieldOcc Name -> DsM (Core a)
1987 rep_one_ip t n = do { MkC v <- lookupOcc (selectorFieldOcc $ unLoc n)
1988 ; MkC ty <- repBangTy t
1989 ; rep2 varBangTypeName [v,ty] }
1990
1991 repConstr (InfixCon st1 st2) Nothing [con]
1992 = do arg1 <- repBangTy st1
1993 arg2 <- repBangTy st2
1994 rep2 infixCName [unC arg1, unC con, unC arg2]
1995
1996 repConstr (InfixCon {}) (Just _) _ =
1997 panic "repConstr: infix GADT constructor should be in a PrefixCon"
1998 repConstr _ _ _ =
1999 panic "repConstr: invariant violated"
2000
2001 ------------ Types -------------------
2002
2003 repTForall :: Core [TH.TyVarBndr] -> Core TH.CxtQ -> Core TH.TypeQ
2004 -> DsM (Core TH.TypeQ)
2005 repTForall (MkC tvars) (MkC ctxt) (MkC ty)
2006 = rep2 forallTName [tvars, ctxt, ty]
2007
2008 repTvar :: Core TH.Name -> DsM (Core TH.TypeQ)
2009 repTvar (MkC s) = rep2 varTName [s]
2010
2011 repTapp :: Core TH.TypeQ -> Core TH.TypeQ -> DsM (Core TH.TypeQ)
2012 repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2]
2013
2014 repTapps :: Core TH.TypeQ -> [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2015 repTapps f [] = return f
2016 repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts }
2017
2018 repTSig :: Core TH.TypeQ -> Core TH.Kind -> DsM (Core TH.TypeQ)
2019 repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki]
2020
2021 repTequality :: DsM (Core TH.TypeQ)
2022 repTequality = rep2 equalityTName []
2023
2024 repTPromotedList :: [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2025 repTPromotedList [] = repPromotedNilTyCon
2026 repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon
2027 ; f <- repTapp tcon t
2028 ; t' <- repTPromotedList ts
2029 ; repTapp f t'
2030 }
2031
2032 repTLit :: Core TH.TyLitQ -> DsM (Core TH.TypeQ)
2033 repTLit (MkC lit) = rep2 litTName [lit]
2034
2035 repTWildCard :: DsM (Core TH.TypeQ)
2036 repTWildCard = rep2 wildCardTName []
2037
2038 --------- Type constructors --------------
2039
2040 repNamedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2041 repNamedTyCon (MkC s) = rep2 conTName [s]
2042
2043 repTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2044 -- Note: not Core Int; it's easier to be direct here
2045 repTupleTyCon i = do dflags <- getDynFlags
2046 rep2 tupleTName [mkIntExprInt dflags i]
2047
2048 repUnboxedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2049 -- Note: not Core Int; it's easier to be direct here
2050 repUnboxedTupleTyCon i = do dflags <- getDynFlags
2051 rep2 unboxedTupleTName [mkIntExprInt dflags i]
2052
2053 repArrowTyCon :: DsM (Core TH.TypeQ)
2054 repArrowTyCon = rep2 arrowTName []
2055
2056 repListTyCon :: DsM (Core TH.TypeQ)
2057 repListTyCon = rep2 listTName []
2058
2059 repPromotedDataCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2060 repPromotedDataCon (MkC s) = rep2 promotedTName [s]
2061
2062 repPromotedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2063 repPromotedTupleTyCon i = do dflags <- getDynFlags
2064 rep2 promotedTupleTName [mkIntExprInt dflags i]
2065
2066 repPromotedNilTyCon :: DsM (Core TH.TypeQ)
2067 repPromotedNilTyCon = rep2 promotedNilTName []
2068
2069 repPromotedConsTyCon :: DsM (Core TH.TypeQ)
2070 repPromotedConsTyCon = rep2 promotedConsTName []
2071
2072 ------------ Kinds -------------------
2073
2074 repPlainTV :: Core TH.Name -> DsM (Core TH.TyVarBndr)
2075 repPlainTV (MkC nm) = rep2 plainTVName [nm]
2076
2077 repKindedTV :: Core TH.Name -> Core TH.Kind -> DsM (Core TH.TyVarBndr)
2078 repKindedTV (MkC nm) (MkC ki) = rep2 kindedTVName [nm, ki]
2079
2080 repKVar :: Core TH.Name -> DsM (Core TH.Kind)
2081 repKVar (MkC s) = rep2 varKName [s]
2082
2083 repKCon :: Core TH.Name -> DsM (Core TH.Kind)
2084 repKCon (MkC s) = rep2 conKName [s]
2085
2086 repKTuple :: Int -> DsM (Core TH.Kind)
2087 repKTuple i = do dflags <- getDynFlags
2088 rep2 tupleKName [mkIntExprInt dflags i]
2089
2090 repKArrow :: DsM (Core TH.Kind)
2091 repKArrow = rep2 arrowKName []
2092
2093 repKList :: DsM (Core TH.Kind)
2094 repKList = rep2 listKName []
2095
2096 repKApp :: Core TH.Kind -> Core TH.Kind -> DsM (Core TH.Kind)
2097 repKApp (MkC k1) (MkC k2) = rep2 appKName [k1, k2]
2098
2099 repKApps :: Core TH.Kind -> [Core TH.Kind] -> DsM (Core TH.Kind)
2100 repKApps f [] = return f
2101 repKApps f (k:ks) = do { f' <- repKApp f k; repKApps f' ks }
2102
2103 repKStar :: DsM (Core TH.Kind)
2104 repKStar = rep2 starKName []
2105
2106 repKConstraint :: DsM (Core TH.Kind)
2107 repKConstraint = rep2 constraintKName []
2108
2109 ----------------------------------------------------------
2110 -- Type family result signature
2111
2112 repNoSig :: DsM (Core TH.FamilyResultSig)
2113 repNoSig = rep2 noSigName []
2114
2115 repKindSig :: Core TH.Kind -> DsM (Core TH.FamilyResultSig)
2116 repKindSig (MkC ki) = rep2 kindSigName [ki]
2117
2118 repTyVarSig :: Core TH.TyVarBndr -> DsM (Core TH.FamilyResultSig)
2119 repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr]
2120
2121 ----------------------------------------------------------
2122 -- Literals
2123
2124 repLiteral :: HsLit -> DsM (Core TH.Lit)
2125 repLiteral (HsStringPrim _ bs)
2126 = do dflags <- getDynFlags
2127 word8_ty <- lookupType word8TyConName
2128 let w8s = unpack bs
2129 w8s_expr = map (\w8 -> mkCoreConApps word8DataCon
2130 [mkWordLit dflags (toInteger w8)]) w8s
2131 rep2 stringPrimLName [mkListExpr word8_ty w8s_expr]
2132 repLiteral lit
2133 = do lit' <- case lit of
2134 HsIntPrim _ i -> mk_integer i
2135 HsWordPrim _ w -> mk_integer w
2136 HsInt _ i -> mk_integer i
2137 HsFloatPrim r -> mk_rational r
2138 HsDoublePrim r -> mk_rational r
2139 HsCharPrim _ c -> mk_char c
2140 _ -> return lit
2141 lit_expr <- dsLit lit'
2142 case mb_lit_name of
2143 Just lit_name -> rep2 lit_name [lit_expr]
2144 Nothing -> notHandled "Exotic literal" (ppr lit)
2145 where
2146 mb_lit_name = case lit of
2147 HsInteger _ _ _ -> Just integerLName
2148 HsInt _ _ -> Just integerLName
2149 HsIntPrim _ _ -> Just intPrimLName
2150 HsWordPrim _ _ -> Just wordPrimLName
2151 HsFloatPrim _ -> Just floatPrimLName
2152 HsDoublePrim _ -> Just doublePrimLName
2153 HsChar _ _ -> Just charLName
2154 HsCharPrim _ _ -> Just charPrimLName
2155 HsString _ _ -> Just stringLName
2156 HsRat _ _ -> Just rationalLName
2157 _ -> Nothing
2158
2159 mk_integer :: Integer -> DsM HsLit
2160 mk_integer i = do integer_ty <- lookupType integerTyConName
2161 return $ HsInteger "" i integer_ty
2162 mk_rational :: FractionalLit -> DsM HsLit
2163 mk_rational r = do rat_ty <- lookupType rationalTyConName
2164 return $ HsRat r rat_ty
2165 mk_string :: FastString -> DsM HsLit
2166 mk_string s = return $ HsString "" s
2167
2168 mk_char :: Char -> DsM HsLit
2169 mk_char c = return $ HsChar "" c
2170
2171 repOverloadedLiteral :: HsOverLit Name -> DsM (Core TH.Lit)
2172 repOverloadedLiteral (OverLit { ol_val = val})
2173 = do { lit <- mk_lit val; repLiteral lit }
2174 -- The type Rational will be in the environment, because
2175 -- the smart constructor 'TH.Syntax.rationalL' uses it in its type,
2176 -- and rationalL is sucked in when any TH stuff is used
2177
2178 mk_lit :: OverLitVal -> DsM HsLit
2179 mk_lit (HsIntegral _ i) = mk_integer i
2180 mk_lit (HsFractional f) = mk_rational f
2181 mk_lit (HsIsString _ s) = mk_string s
2182
2183 repNameS :: Core String -> DsM (Core TH.Name)
2184 repNameS (MkC name) = rep2 mkNameSName [name]
2185
2186 --------------- Miscellaneous -------------------
2187
2188 repGensym :: Core String -> DsM (Core (TH.Q TH.Name))
2189 repGensym (MkC lit_str) = rep2 newNameName [lit_str]
2190
2191 repBindQ :: Type -> Type -- a and b
2192 -> Core (TH.Q a) -> Core (a -> TH.Q b) -> DsM (Core (TH.Q b))
2193 repBindQ ty_a ty_b (MkC x) (MkC y)
2194 = rep2 bindQName [Type ty_a, Type ty_b, x, y]
2195
2196 repSequenceQ :: Type -> Core [TH.Q a] -> DsM (Core (TH.Q [a]))
2197 repSequenceQ ty_a (MkC list)
2198 = rep2 sequenceQName [Type ty_a, list]
2199
2200 repUnboundVar :: Core TH.Name -> DsM (Core TH.ExpQ)
2201 repUnboundVar (MkC name) = rep2 unboundVarEName [name]
2202
2203 ------------ Lists -------------------
2204 -- turn a list of patterns into a single pattern matching a list
2205
2206 repList :: Name -> (a -> DsM (Core b))
2207 -> [a] -> DsM (Core [b])
2208 repList tc_name f args
2209 = do { args1 <- mapM f args
2210 ; coreList tc_name args1 }
2211
2212 coreList :: Name -- Of the TyCon of the element type
2213 -> [Core a] -> DsM (Core [a])
2214 coreList tc_name es
2215 = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) }
2216
2217 coreList' :: Type -- The element type
2218 -> [Core a] -> Core [a]
2219 coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es ))
2220
2221 nonEmptyCoreList :: [Core a] -> Core [a]
2222 -- The list must be non-empty so we can get the element type
2223 -- Otherwise use coreList
2224 nonEmptyCoreList [] = panic "coreList: empty argument"
2225 nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs))
2226
2227 coreStringLit :: String -> DsM (Core String)
2228 coreStringLit s = do { z <- mkStringExpr s; return(MkC z) }
2229
2230 ------------------- Maybe ------------------
2231
2232 -- | Construct Core expression for Nothing of a given type name
2233 coreNothing :: Name -- ^ Name of the TyCon of the element type
2234 -> DsM (Core (Maybe a))
2235 coreNothing tc_name =
2236 do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) }
2237
2238 -- | Construct Core expression for Nothing of a given type
2239 coreNothing' :: Type -- ^ The element type
2240 -> Core (Maybe a)
2241 coreNothing' elt_ty = MkC (mkNothingExpr elt_ty)
2242
2243 -- | Store given Core expression in a Just of a given type name
2244 coreJust :: Name -- ^ Name of the TyCon of the element type
2245 -> Core a -> DsM (Core (Maybe a))
2246 coreJust tc_name es
2247 = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) }
2248
2249 -- | Store given Core expression in a Just of a given type
2250 coreJust' :: Type -- ^ The element type
2251 -> Core a -> Core (Maybe a)
2252 coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es))
2253
2254 ------------ Literals & Variables -------------------
2255
2256 coreIntLit :: Int -> DsM (Core Int)
2257 coreIntLit i = do dflags <- getDynFlags
2258 return (MkC (mkIntExprInt dflags i))
2259
2260 coreVar :: Id -> Core TH.Name -- The Id has type Name
2261 coreVar id = MkC (Var id)
2262
2263 ----------------- Failure -----------------------
2264 notHandledL :: SrcSpan -> String -> SDoc -> DsM a
2265 notHandledL loc what doc
2266 | isGoodSrcSpan loc
2267 = putSrcSpanDs loc $ notHandled what doc
2268 | otherwise
2269 = notHandled what doc
2270
2271 notHandled :: String -> SDoc -> DsM a
2272 notHandled what doc = failWithDs msg
2273 where
2274 msg = hang (text what <+> text "not (yet) handled by Template Haskell")
2275 2 doc