Have addModFinalizer expose the local type environment.
[ghc.git] / compiler / deSugar / DsMeta.hs
1 {-# LANGUAGE CPP, TypeFamilies #-}
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 NameSet
44 import TcType
45 import TyCon
46 import TysWiredIn
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_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 { bndrs = hsSigTvBinders valds
123 ++ hsGroupBinders group
124 ++ hsPatSynSelectors valds
125 ; instds = tyclds >>= group_instds } ;
126 ss <- mkGenSyms bndrs ;
127
128 -- Bind all the names mainly to avoid repeated use of explicit strings.
129 -- Thus we get
130 -- do { t :: String <- genSym "T" ;
131 -- return (Data t [] ...more t's... }
132 -- The other important reason is that the output must mention
133 -- only "T", not "Foo:T" where Foo is the current module
134
135 decls <- addBinds ss (
136 do { val_ds <- rep_val_binds valds
137 ; _ <- mapM no_splice splcds
138 ; tycl_ds <- mapM repTyClD (tyClGroupTyClDecls tyclds)
139 ; role_ds <- mapM repRoleD (concatMap group_roles tyclds)
140 ; inst_ds <- mapM repInstD instds
141 ; deriv_ds <- mapM repStandaloneDerivD derivds
142 ; fix_ds <- mapM repFixD fixds
143 ; _ <- mapM no_default_decl defds
144 ; for_ds <- mapM repForD fords
145 ; _ <- mapM no_warn (concatMap (wd_warnings . unLoc)
146 warnds)
147 ; ann_ds <- mapM repAnnD annds
148 ; rule_ds <- mapM repRuleD (concatMap (rds_rules . unLoc)
149 ruleds)
150 ; _ <- mapM no_vect vects
151 ; _ <- mapM no_doc docs
152
153 -- more needed
154 ; return (de_loc $ sort_by_loc $
155 val_ds ++ catMaybes tycl_ds ++ role_ds
156 ++ (concat fix_ds)
157 ++ inst_ds ++ rule_ds ++ for_ds
158 ++ ann_ds ++ deriv_ds) }) ;
159
160 decl_ty <- lookupType decQTyConName ;
161 let { core_list = coreList' decl_ty decls } ;
162
163 dec_ty <- lookupType decTyConName ;
164 q_decs <- repSequenceQ dec_ty core_list ;
165
166 wrapGenSyms ss q_decs
167 }
168 where
169 no_splice (L loc _)
170 = notHandledL loc "Splices within declaration brackets" empty
171 no_default_decl (L loc decl)
172 = notHandledL loc "Default declarations" (ppr decl)
173 no_warn (L loc (Warning thing _))
174 = notHandledL loc "WARNING and DEPRECATION pragmas" $
175 text "Pragma for declaration of" <+> ppr thing
176 no_vect (L loc decl)
177 = notHandledL loc "Vectorisation pragmas" (ppr decl)
178 no_doc (L loc _)
179 = notHandledL loc "Haddock documentation" empty
180
181 hsSigTvBinders :: HsValBinds Name -> [Name]
182 -- See Note [Scoped type variables in bindings]
183 hsSigTvBinders binds
184 = concatMap get_scoped_tvs sigs
185 where
186 get_scoped_tvs :: LSig Name -> [Name]
187 -- Both implicit and explicit quantified variables
188 -- We need the implicit ones for f :: forall (a::k). blah
189 -- here 'k' scopes too
190 get_scoped_tvs (L _ (TypeSig _ sig))
191 | HsIB { hsib_vars = implicit_vars
192 , hsib_body = hs_ty } <- hswc_body sig
193 , (explicit_vars, _) <- splitLHsForAllTy hs_ty
194 = implicit_vars ++ map hsLTyVarName explicit_vars
195 get_scoped_tvs _ = []
196
197 sigs = case binds of
198 ValBindsIn _ sigs -> sigs
199 ValBindsOut _ sigs -> sigs
200
201 {- Notes
202
203 Note [Scoped type variables in bindings]
204 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
205 Consider
206 f :: forall a. a -> a
207 f x = x::a
208 Here the 'forall a' brings 'a' into scope over the binding group.
209 To achieve this we
210
211 a) Gensym a binding for 'a' at the same time as we do one for 'f'
212 collecting the relevant binders with hsSigTvBinders
213
214 b) When processing the 'forall', don't gensym
215
216 The relevant places are signposted with references to this Note
217
218 Note [Binders and occurrences]
219 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
220 When we desugar [d| data T = MkT |]
221 we want to get
222 Data "T" [] [Con "MkT" []] []
223 and *not*
224 Data "Foo:T" [] [Con "Foo:MkT" []] []
225 That is, the new data decl should fit into whatever new module it is
226 asked to fit in. We do *not* clone, though; no need for this:
227 Data "T79" ....
228
229 But if we see this:
230 data T = MkT
231 foo = reifyDecl T
232
233 then we must desugar to
234 foo = Data "Foo:T" [] [Con "Foo:MkT" []] []
235
236 So in repTopDs we bring the binders into scope with mkGenSyms and addBinds.
237 And we use lookupOcc, rather than lookupBinder
238 in repTyClD and repC.
239
240 -}
241
242 -- represent associated family instances
243 --
244 repTyClD :: LTyClDecl Name -> DsM (Maybe (SrcSpan, Core TH.DecQ))
245
246 repTyClD (L loc (FamDecl { tcdFam = fam })) = liftM Just $ repFamilyDecl (L loc fam)
247
248 repTyClD (L loc (SynDecl { tcdLName = tc, tcdTyVars = tvs, tcdRhs = rhs }))
249 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
250 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
251 repSynDecl tc1 bndrs rhs
252 ; return (Just (loc, dec)) }
253
254 repTyClD (L loc (DataDecl { tcdLName = tc, tcdTyVars = tvs, tcdDataDefn = defn }))
255 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
256 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
257 repDataDefn tc1 bndrs Nothing defn
258 ; return (Just (loc, dec)) }
259
260 repTyClD (L loc (ClassDecl { tcdCtxt = cxt, tcdLName = cls,
261 tcdTyVars = tvs, tcdFDs = fds,
262 tcdSigs = sigs, tcdMeths = meth_binds,
263 tcdATs = ats, tcdATDefs = atds }))
264 = do { cls1 <- lookupLOcc cls -- See note [Binders and occurrences]
265 ; dec <- addTyVarBinds tvs $ \bndrs ->
266 do { cxt1 <- repLContext cxt
267 ; sigs1 <- rep_sigs sigs
268 ; binds1 <- rep_binds meth_binds
269 ; fds1 <- repLFunDeps fds
270 ; ats1 <- repFamilyDecls ats
271 ; atds1 <- repAssocTyFamDefaults atds
272 ; decls1 <- coreList decQTyConName (ats1 ++ atds1 ++ sigs1 ++ binds1)
273 ; repClass cxt1 cls1 bndrs fds1 decls1
274 }
275 ; return $ Just (loc, dec)
276 }
277
278 -------------------------
279 repRoleD :: LRoleAnnotDecl Name -> DsM (SrcSpan, Core TH.DecQ)
280 repRoleD (L loc (RoleAnnotDecl tycon roles))
281 = do { tycon1 <- lookupLOcc tycon
282 ; roles1 <- mapM repRole roles
283 ; roles2 <- coreList roleTyConName roles1
284 ; dec <- repRoleAnnotD tycon1 roles2
285 ; return (loc, dec) }
286
287 -------------------------
288 repDataDefn :: Core TH.Name -> Core [TH.TyVarBndr]
289 -> Maybe (Core [TH.TypeQ])
290 -> HsDataDefn Name
291 -> DsM (Core TH.DecQ)
292 repDataDefn tc bndrs opt_tys
293 (HsDataDefn { dd_ND = new_or_data, dd_ctxt = cxt, dd_kindSig = ksig
294 , dd_cons = cons, dd_derivs = mb_derivs })
295 = do { cxt1 <- repLContext cxt
296 ; derivs1 <- repDerivs mb_derivs
297 ; case (new_or_data, cons) of
298 (NewType, [con]) -> do { con' <- repC con
299 ; ksig' <- repMaybeLKind ksig
300 ; repNewtype cxt1 tc bndrs opt_tys ksig' con'
301 derivs1 }
302 (NewType, _) -> failWithDs (text "Multiple constructors for newtype:"
303 <+> pprQuotedList
304 (getConNames $ unLoc $ head cons))
305 (DataType, _) -> do { ksig' <- repMaybeLKind ksig
306 ; consL <- mapM repC cons
307 ; cons1 <- coreList conQTyConName consL
308 ; repData cxt1 tc bndrs opt_tys ksig' cons1
309 derivs1 }
310 }
311
312 repSynDecl :: Core TH.Name -> Core [TH.TyVarBndr]
313 -> LHsType Name
314 -> DsM (Core TH.DecQ)
315 repSynDecl tc bndrs ty
316 = do { ty1 <- repLTy ty
317 ; repTySyn tc bndrs ty1 }
318
319 repFamilyDecl :: LFamilyDecl Name -> DsM (SrcSpan, Core TH.DecQ)
320 repFamilyDecl decl@(L loc (FamilyDecl { fdInfo = info,
321 fdLName = tc,
322 fdTyVars = tvs,
323 fdResultSig = L _ resultSig,
324 fdInjectivityAnn = injectivity }))
325 = do { tc1 <- lookupLOcc tc -- See note [Binders and occurrences]
326 ; let mkHsQTvs :: [LHsTyVarBndr Name] -> LHsQTyVars Name
327 mkHsQTvs tvs = HsQTvs { hsq_implicit = [], hsq_explicit = tvs
328 , hsq_dependent = emptyNameSet }
329 resTyVar = case resultSig of
330 TyVarSig bndr -> mkHsQTvs [bndr]
331 _ -> mkHsQTvs []
332 ; dec <- addTyClTyVarBinds tvs $ \bndrs ->
333 addTyClTyVarBinds resTyVar $ \_ ->
334 case info of
335 ClosedTypeFamily Nothing ->
336 notHandled "abstract closed type family" (ppr decl)
337 ClosedTypeFamily (Just eqns) ->
338 do { eqns1 <- mapM repTyFamEqn eqns
339 ; eqns2 <- coreList tySynEqnQTyConName eqns1
340 ; result <- repFamilyResultSig resultSig
341 ; inj <- repInjectivityAnn injectivity
342 ; repClosedFamilyD tc1 bndrs result inj eqns2 }
343 OpenTypeFamily ->
344 do { result <- repFamilyResultSig resultSig
345 ; inj <- repInjectivityAnn injectivity
346 ; repOpenFamilyD tc1 bndrs result inj }
347 DataFamily ->
348 do { kind <- repFamilyResultSigToMaybeKind resultSig
349 ; repDataFamilyD tc1 bndrs kind }
350 ; return (loc, dec)
351 }
352
353 -- | Represent result signature of a type family
354 repFamilyResultSig :: FamilyResultSig Name -> DsM (Core TH.FamilyResultSig)
355 repFamilyResultSig NoSig = repNoSig
356 repFamilyResultSig (KindSig ki) = do { ki' <- repLKind ki
357 ; repKindSig ki' }
358 repFamilyResultSig (TyVarSig bndr) = do { bndr' <- repTyVarBndr bndr
359 ; repTyVarSig bndr' }
360
361 -- | Represent result signature using a Maybe Kind. Used with data families,
362 -- where the result signature can be either missing or a kind but never a named
363 -- result variable.
364 repFamilyResultSigToMaybeKind :: FamilyResultSig Name
365 -> DsM (Core (Maybe TH.Kind))
366 repFamilyResultSigToMaybeKind NoSig =
367 do { coreNothing kindTyConName }
368 repFamilyResultSigToMaybeKind (KindSig ki) =
369 do { ki' <- repLKind ki
370 ; coreJust kindTyConName ki' }
371 repFamilyResultSigToMaybeKind _ = panic "repFamilyResultSigToMaybeKind"
372
373 -- | Represent injectivity annotation of a type family
374 repInjectivityAnn :: Maybe (LInjectivityAnn Name)
375 -> DsM (Core (Maybe TH.InjectivityAnn))
376 repInjectivityAnn Nothing =
377 do { coreNothing injAnnTyConName }
378 repInjectivityAnn (Just (L _ (InjectivityAnn lhs rhs))) =
379 do { lhs' <- lookupBinder (unLoc lhs)
380 ; rhs1 <- mapM (lookupBinder . unLoc) rhs
381 ; rhs2 <- coreList nameTyConName rhs1
382 ; injAnn <- rep2 injectivityAnnName [unC lhs', unC rhs2]
383 ; coreJust injAnnTyConName injAnn }
384
385 repFamilyDecls :: [LFamilyDecl Name] -> DsM [Core TH.DecQ]
386 repFamilyDecls fds = liftM de_loc (mapM repFamilyDecl fds)
387
388 repAssocTyFamDefaults :: [LTyFamDefltEqn Name] -> DsM [Core TH.DecQ]
389 repAssocTyFamDefaults = mapM rep_deflt
390 where
391 -- very like repTyFamEqn, but different in the details
392 rep_deflt :: LTyFamDefltEqn Name -> DsM (Core TH.DecQ)
393 rep_deflt (L _ (TyFamEqn { tfe_tycon = tc
394 , tfe_pats = bndrs
395 , tfe_rhs = rhs }))
396 = addTyClTyVarBinds bndrs $ \ _ ->
397 do { tc1 <- lookupLOcc tc
398 ; tys1 <- repLTys (hsLTyVarBndrsToTypes bndrs)
399 ; tys2 <- coreList typeQTyConName tys1
400 ; rhs1 <- repLTy rhs
401 ; eqn1 <- repTySynEqn tys2 rhs1
402 ; repTySynInst tc1 eqn1 }
403
404 -------------------------
405 -- represent fundeps
406 --
407 repLFunDeps :: [Located (FunDep (Located Name))] -> DsM (Core [TH.FunDep])
408 repLFunDeps fds = repList funDepTyConName repLFunDep fds
409
410 repLFunDep :: Located (FunDep (Located Name)) -> DsM (Core TH.FunDep)
411 repLFunDep (L _ (xs, ys))
412 = do xs' <- repList nameTyConName (lookupBinder . unLoc) xs
413 ys' <- repList nameTyConName (lookupBinder . unLoc) ys
414 repFunDep xs' ys'
415
416 -- Represent instance declarations
417 --
418 repInstD :: LInstDecl Name -> DsM (SrcSpan, Core TH.DecQ)
419 repInstD (L loc (TyFamInstD { tfid_inst = fi_decl }))
420 = do { dec <- repTyFamInstD fi_decl
421 ; return (loc, dec) }
422 repInstD (L loc (DataFamInstD { dfid_inst = fi_decl }))
423 = do { dec <- repDataFamInstD fi_decl
424 ; return (loc, dec) }
425 repInstD (L loc (ClsInstD { cid_inst = cls_decl }))
426 = do { dec <- repClsInstD cls_decl
427 ; return (loc, dec) }
428
429 repClsInstD :: ClsInstDecl Name -> DsM (Core TH.DecQ)
430 repClsInstD (ClsInstDecl { cid_poly_ty = ty, cid_binds = binds
431 , cid_sigs = prags, cid_tyfam_insts = ats
432 , cid_datafam_insts = adts
433 , cid_overlap_mode = overlap
434 })
435 = addSimpleTyVarBinds tvs $
436 -- We must bring the type variables into scope, so their
437 -- occurrences don't fail, even though the binders don't
438 -- appear in the resulting data structure
439 --
440 -- But we do NOT bring the binders of 'binds' into scope
441 -- because they are properly regarded as occurrences
442 -- For example, the method names should be bound to
443 -- the selector Ids, not to fresh names (Trac #5410)
444 --
445 do { cxt1 <- repLContext cxt
446 ; inst_ty1 <- repLTy inst_ty
447 ; binds1 <- rep_binds binds
448 ; prags1 <- rep_sigs prags
449 ; ats1 <- mapM (repTyFamInstD . unLoc) ats
450 ; adts1 <- mapM (repDataFamInstD . unLoc) adts
451 ; decls <- coreList decQTyConName (ats1 ++ adts1 ++ binds1 ++ prags1)
452 ; rOver <- repOverlap (fmap unLoc overlap)
453 ; repInst rOver cxt1 inst_ty1 decls }
454 where
455 (tvs, cxt, inst_ty) = splitLHsInstDeclTy ty
456
457 repStandaloneDerivD :: LDerivDecl Name -> DsM (SrcSpan, Core TH.DecQ)
458 repStandaloneDerivD (L loc (DerivDecl { deriv_type = ty }))
459 = do { dec <- addSimpleTyVarBinds tvs $
460 do { cxt' <- repLContext cxt
461 ; inst_ty' <- repLTy inst_ty
462 ; repDeriv cxt' inst_ty' }
463 ; return (loc, dec) }
464 where
465 (tvs, cxt, inst_ty) = splitLHsInstDeclTy ty
466
467 repTyFamInstD :: TyFamInstDecl Name -> DsM (Core TH.DecQ)
468 repTyFamInstD decl@(TyFamInstDecl { tfid_eqn = eqn })
469 = do { let tc_name = tyFamInstDeclLName decl
470 ; tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
471 ; eqn1 <- repTyFamEqn eqn
472 ; repTySynInst tc eqn1 }
473
474 repTyFamEqn :: LTyFamInstEqn Name -> DsM (Core TH.TySynEqnQ)
475 repTyFamEqn (L _ (TyFamEqn { tfe_pats = HsIB { hsib_body = tys
476 , hsib_vars = var_names }
477 , tfe_rhs = rhs }))
478 = do { let hs_tvs = HsQTvs { hsq_implicit = var_names
479 , hsq_explicit = []
480 , hsq_dependent = emptyNameSet } -- Yuk
481 ; addTyClTyVarBinds hs_tvs $ \ _ ->
482 do { tys1 <- repLTys tys
483 ; tys2 <- coreList typeQTyConName tys1
484 ; rhs1 <- repLTy rhs
485 ; repTySynEqn tys2 rhs1 } }
486
487 repDataFamInstD :: DataFamInstDecl Name -> DsM (Core TH.DecQ)
488 repDataFamInstD (DataFamInstDecl { dfid_tycon = tc_name
489 , dfid_pats = HsIB { hsib_body = tys, hsib_vars = var_names }
490 , dfid_defn = defn })
491 = do { tc <- lookupLOcc tc_name -- See note [Binders and occurrences]
492 ; let hs_tvs = HsQTvs { hsq_implicit = var_names
493 , hsq_explicit = []
494 , hsq_dependent = emptyNameSet } -- Yuk
495 ; addTyClTyVarBinds hs_tvs $ \ bndrs ->
496 do { tys1 <- repList typeQTyConName repLTy tys
497 ; repDataDefn tc bndrs (Just tys1) defn } }
498
499 repForD :: Located (ForeignDecl Name) -> DsM (SrcSpan, Core TH.DecQ)
500 repForD (L loc (ForeignImport { fd_name = name, fd_sig_ty = typ
501 , fd_fi = CImport (L _ cc) (L _ s) mch cis _ }))
502 = do MkC name' <- lookupLOcc name
503 MkC typ' <- repHsSigType typ
504 MkC cc' <- repCCallConv cc
505 MkC s' <- repSafety s
506 cis' <- conv_cimportspec cis
507 MkC str <- coreStringLit (static ++ chStr ++ cis')
508 dec <- rep2 forImpDName [cc', s', str, name', typ']
509 return (loc, dec)
510 where
511 conv_cimportspec (CLabel cls) = notHandled "Foreign label" (doubleQuotes (ppr cls))
512 conv_cimportspec (CFunction DynamicTarget) = return "dynamic"
513 conv_cimportspec (CFunction (StaticTarget _ fs _ True))
514 = return (unpackFS fs)
515 conv_cimportspec (CFunction (StaticTarget _ _ _ False))
516 = panic "conv_cimportspec: values not supported yet"
517 conv_cimportspec CWrapper = return "wrapper"
518 -- these calling conventions do not support headers and the static keyword
519 raw_cconv = cc == PrimCallConv || cc == JavaScriptCallConv
520 static = case cis of
521 CFunction (StaticTarget _ _ _ _) | not raw_cconv -> "static "
522 _ -> ""
523 chStr = case mch of
524 Just (Header _ h) | not raw_cconv -> unpackFS h ++ " "
525 _ -> ""
526 repForD decl = notHandled "Foreign declaration" (ppr decl)
527
528 repCCallConv :: CCallConv -> DsM (Core TH.Callconv)
529 repCCallConv CCallConv = rep2 cCallName []
530 repCCallConv StdCallConv = rep2 stdCallName []
531 repCCallConv CApiConv = rep2 cApiCallName []
532 repCCallConv PrimCallConv = rep2 primCallName []
533 repCCallConv JavaScriptCallConv = rep2 javaScriptCallName []
534
535 repSafety :: Safety -> DsM (Core TH.Safety)
536 repSafety PlayRisky = rep2 unsafeName []
537 repSafety PlayInterruptible = rep2 interruptibleName []
538 repSafety PlaySafe = rep2 safeName []
539
540 repFixD :: LFixitySig Name -> DsM [(SrcSpan, Core TH.DecQ)]
541 repFixD (L loc (FixitySig names (Fixity _ prec dir)))
542 = do { MkC prec' <- coreIntLit prec
543 ; let rep_fn = case dir of
544 InfixL -> infixLDName
545 InfixR -> infixRDName
546 InfixN -> infixNDName
547 ; let do_one name
548 = do { MkC name' <- lookupLOcc name
549 ; dec <- rep2 rep_fn [prec', name']
550 ; return (loc,dec) }
551 ; mapM do_one names }
552
553 repRuleD :: LRuleDecl Name -> DsM (SrcSpan, Core TH.DecQ)
554 repRuleD (L loc (HsRule n act bndrs lhs _ rhs _))
555 = do { let bndr_names = concatMap ruleBndrNames bndrs
556 ; ss <- mkGenSyms bndr_names
557 ; rule1 <- addBinds ss $
558 do { bndrs' <- repList ruleBndrQTyConName repRuleBndr bndrs
559 ; n' <- coreStringLit $ unpackFS $ snd $ unLoc n
560 ; act' <- repPhases act
561 ; lhs' <- repLE lhs
562 ; rhs' <- repLE rhs
563 ; repPragRule n' bndrs' lhs' rhs' act' }
564 ; rule2 <- wrapGenSyms ss rule1
565 ; return (loc, rule2) }
566
567 ruleBndrNames :: LRuleBndr Name -> [Name]
568 ruleBndrNames (L _ (RuleBndr n)) = [unLoc n]
569 ruleBndrNames (L _ (RuleBndrSig n sig))
570 | HsWC { hswc_body = HsIB { hsib_vars = vars }} <- sig
571 = unLoc n : vars
572
573 repRuleBndr :: LRuleBndr Name -> DsM (Core TH.RuleBndrQ)
574 repRuleBndr (L _ (RuleBndr n))
575 = do { MkC n' <- lookupLBinder n
576 ; rep2 ruleVarName [n'] }
577 repRuleBndr (L _ (RuleBndrSig n sig))
578 = do { MkC n' <- lookupLBinder n
579 ; MkC ty' <- repLTy (hsSigWcType sig)
580 ; rep2 typedRuleVarName [n', ty'] }
581
582 repAnnD :: LAnnDecl Name -> DsM (SrcSpan, Core TH.DecQ)
583 repAnnD (L loc (HsAnnotation _ ann_prov (L _ exp)))
584 = do { target <- repAnnProv ann_prov
585 ; exp' <- repE exp
586 ; dec <- repPragAnn target exp'
587 ; return (loc, dec) }
588
589 repAnnProv :: AnnProvenance Name -> DsM (Core TH.AnnTarget)
590 repAnnProv (ValueAnnProvenance (L _ n))
591 = do { MkC n' <- globalVar n -- ANNs are allowed only at top-level
592 ; rep2 valueAnnotationName [ n' ] }
593 repAnnProv (TypeAnnProvenance (L _ n))
594 = do { MkC n' <- globalVar n
595 ; rep2 typeAnnotationName [ n' ] }
596 repAnnProv ModuleAnnProvenance
597 = rep2 moduleAnnotationName []
598
599 -------------------------------------------------------
600 -- Constructors
601 -------------------------------------------------------
602
603 repC :: LConDecl Name -> DsM (Core TH.ConQ)
604 repC (L _ (ConDeclH98 { con_name = con
605 , con_qvars = Nothing, con_cxt = Nothing
606 , con_details = details }))
607 = repDataCon con details
608
609 repC (L _ (ConDeclH98 { con_name = con
610 , con_qvars = mcon_tvs, con_cxt = mcxt
611 , con_details = details }))
612 = do { let con_tvs = fromMaybe emptyLHsQTvs mcon_tvs
613 ctxt = unLoc $ fromMaybe (noLoc []) mcxt
614 ; addTyVarBinds con_tvs $ \ ex_bndrs ->
615 do { c' <- repDataCon con details
616 ; ctxt' <- repContext ctxt
617 ; if isEmptyLHsQTvs con_tvs && null ctxt
618 then return c'
619 else rep2 forallCName ([unC ex_bndrs, unC ctxt', unC c'])
620 }
621 }
622
623 repC (L _ (ConDeclGADT { con_names = cons
624 , con_type = res_ty@(HsIB { hsib_vars = con_vars })}))
625 | (details, res_ty', L _ [] , []) <- gadtDetails
626 , [] <- con_vars
627 -- no implicit or explicit variables, no context = no need for a forall
628 = do { let doc = text "In the constructor for " <+> ppr (head cons)
629 ; (hs_details, gadt_res_ty) <-
630 updateGadtResult failWithDs doc details res_ty'
631 ; repGadtDataCons cons hs_details gadt_res_ty }
632
633 | (details,res_ty',ctxt, tvs) <- gadtDetails
634 = do { let doc = text "In the constructor for " <+> ppr (head cons)
635 con_tvs = HsQTvs { hsq_implicit = []
636 , hsq_explicit = (map (noLoc . UserTyVar . noLoc)
637 con_vars) ++ tvs
638 , hsq_dependent = emptyNameSet }
639 ; addTyVarBinds con_tvs $ \ ex_bndrs -> do
640 { (hs_details, gadt_res_ty) <-
641 updateGadtResult failWithDs doc details res_ty'
642 ; c' <- repGadtDataCons cons hs_details gadt_res_ty
643 ; ctxt' <- repContext (unLoc ctxt)
644 ; rep2 forallCName ([unC ex_bndrs, unC ctxt', unC c']) } }
645 where
646 gadtDetails = gadtDeclDetails res_ty
647
648 repSrcUnpackedness :: SrcUnpackedness -> DsM (Core TH.SourceUnpackednessQ)
649 repSrcUnpackedness SrcUnpack = rep2 sourceUnpackName []
650 repSrcUnpackedness SrcNoUnpack = rep2 sourceNoUnpackName []
651 repSrcUnpackedness NoSrcUnpack = rep2 noSourceUnpackednessName []
652
653 repSrcStrictness :: SrcStrictness -> DsM (Core TH.SourceStrictnessQ)
654 repSrcStrictness SrcLazy = rep2 sourceLazyName []
655 repSrcStrictness SrcStrict = rep2 sourceStrictName []
656 repSrcStrictness NoSrcStrict = rep2 noSourceStrictnessName []
657
658 repBangTy :: LBangType Name -> DsM (Core (TH.BangTypeQ))
659 repBangTy ty = do
660 MkC u <- repSrcUnpackedness su'
661 MkC s <- repSrcStrictness ss'
662 MkC b <- rep2 bangName [u, s]
663 MkC t <- repLTy ty'
664 rep2 bangTypeName [b, t]
665 where
666 (su', ss', ty') = case ty of
667 L _ (HsBangTy (HsSrcBang _ su ss) ty) -> (su, ss, ty)
668 _ -> (NoSrcUnpack, NoSrcStrict, ty)
669
670 -------------------------------------------------------
671 -- Deriving clause
672 -------------------------------------------------------
673
674 repDerivs :: HsDeriving Name -> DsM (Core TH.CxtQ)
675 repDerivs deriv = do
676 let clauses = case deriv of
677 Nothing -> []
678 Just (L _ ctxt) -> ctxt
679 tys <- repList typeQTyConName
680 (rep_deriv . hsSigType)
681 clauses
682 :: DsM (Core [TH.PredQ])
683 repCtxt tys
684 where
685 rep_deriv :: LHsType Name -> DsM (Core TH.TypeQ)
686 rep_deriv (L _ ty) = repTy ty
687
688 -------------------------------------------------------
689 -- Signatures in a class decl, or a group of bindings
690 -------------------------------------------------------
691
692 rep_sigs :: [LSig Name] -> DsM [Core TH.DecQ]
693 rep_sigs sigs = do locs_cores <- rep_sigs' sigs
694 return $ de_loc $ sort_by_loc locs_cores
695
696 rep_sigs' :: [LSig Name] -> DsM [(SrcSpan, Core TH.DecQ)]
697 -- We silently ignore ones we don't recognise
698 rep_sigs' sigs = do { sigs1 <- mapM rep_sig sigs ;
699 return (concat sigs1) }
700
701 rep_sig :: LSig Name -> DsM [(SrcSpan, Core TH.DecQ)]
702 rep_sig (L loc (TypeSig nms ty)) = mapM (rep_wc_ty_sig sigDName loc ty) nms
703 rep_sig (L loc (PatSynSig nms ty)) = mapM (rep_patsyn_ty_sig loc ty) nms
704 rep_sig (L loc (ClassOpSig is_deflt nms ty))
705 | is_deflt = mapM (rep_ty_sig defaultSigDName loc ty) nms
706 | otherwise = mapM (rep_ty_sig sigDName loc ty) nms
707 rep_sig d@(L _ (IdSig {})) = pprPanic "rep_sig IdSig" (ppr d)
708 rep_sig (L _ (FixSig {})) = return [] -- fixity sigs at top level
709 rep_sig (L loc (InlineSig nm ispec)) = rep_inline nm ispec loc
710 rep_sig (L loc (SpecSig nm tys ispec))
711 = concatMapM (\t -> rep_specialise nm t ispec loc) tys
712 rep_sig (L loc (SpecInstSig _ ty)) = rep_specialiseInst ty loc
713 rep_sig (L _ (MinimalSig {})) = notHandled "MINIMAL pragmas" empty
714
715 rep_ty_sig :: Name -> SrcSpan -> LHsSigType Name -> Located Name
716 -> DsM (SrcSpan, Core TH.DecQ)
717 rep_ty_sig mk_sig loc sig_ty nm
718 = do { nm1 <- lookupLOcc nm
719 ; ty1 <- repHsSigType sig_ty
720 ; sig <- repProto mk_sig nm1 ty1
721 ; return (loc, sig) }
722
723 rep_patsyn_ty_sig :: SrcSpan -> LHsSigType Name -> Located Name
724 -> DsM (SrcSpan, Core TH.DecQ)
725 -- represents a pattern synonym type signature; see NOTE [Pattern
726 -- synonym signatures and Template Haskell]
727 rep_patsyn_ty_sig loc sig_ty nm
728 = do { nm1 <- lookupLOcc nm
729 ; ty1 <- repHsPatSynSigType sig_ty
730 ; sig <- repProto patSynSigDName nm1 ty1
731 ; return (loc, sig) }
732
733 rep_wc_ty_sig :: Name -> SrcSpan -> LHsSigWcType Name -> Located Name
734 -> DsM (SrcSpan, Core TH.DecQ)
735 -- We must special-case the top-level explicit for-all of a TypeSig
736 -- See Note [Scoped type variables in bindings]
737 rep_wc_ty_sig mk_sig loc sig_ty nm
738 | HsIB { hsib_vars = implicit_tvs, hsib_body = hs_ty } <- hswc_body sig_ty
739 , (explicit_tvs, ctxt, ty) <- splitLHsSigmaTy hs_ty
740 = do { nm1 <- lookupLOcc nm
741 ; let rep_in_scope_tv tv = do { name <- lookupBinder (hsLTyVarName tv)
742 ; repTyVarBndrWithKind tv name }
743 all_tvs = map (noLoc . UserTyVar . noLoc) implicit_tvs ++ explicit_tvs
744 ; th_tvs <- repList tyVarBndrTyConName rep_in_scope_tv all_tvs
745 ; th_ctxt <- repLContext ctxt
746 ; th_ty <- repLTy ty
747 ; ty1 <- if null all_tvs && null (unLoc ctxt)
748 then return th_ty
749 else repTForall th_tvs th_ctxt th_ty
750 ; sig <- repProto mk_sig nm1 ty1
751 ; return (loc, sig) }
752
753 rep_inline :: Located Name
754 -> InlinePragma -- Never defaultInlinePragma
755 -> SrcSpan
756 -> DsM [(SrcSpan, Core TH.DecQ)]
757 rep_inline nm ispec loc
758 = do { nm1 <- lookupLOcc nm
759 ; inline <- repInline $ inl_inline ispec
760 ; rm <- repRuleMatch $ inl_rule ispec
761 ; phases <- repPhases $ inl_act ispec
762 ; pragma <- repPragInl nm1 inline rm phases
763 ; return [(loc, pragma)]
764 }
765
766 rep_specialise :: Located Name -> LHsSigType Name -> InlinePragma -> SrcSpan
767 -> DsM [(SrcSpan, Core TH.DecQ)]
768 rep_specialise nm ty ispec loc
769 = do { nm1 <- lookupLOcc nm
770 ; ty1 <- repHsSigType ty
771 ; phases <- repPhases $ inl_act ispec
772 ; let inline = inl_inline ispec
773 ; pragma <- if isEmptyInlineSpec inline
774 then -- SPECIALISE
775 repPragSpec nm1 ty1 phases
776 else -- SPECIALISE INLINE
777 do { inline1 <- repInline inline
778 ; repPragSpecInl nm1 ty1 inline1 phases }
779 ; return [(loc, pragma)]
780 }
781
782 rep_specialiseInst :: LHsSigType Name -> SrcSpan -> DsM [(SrcSpan, Core TH.DecQ)]
783 rep_specialiseInst ty loc
784 = do { ty1 <- repHsSigType ty
785 ; pragma <- repPragSpecInst ty1
786 ; return [(loc, pragma)] }
787
788 repInline :: InlineSpec -> DsM (Core TH.Inline)
789 repInline NoInline = dataCon noInlineDataConName
790 repInline Inline = dataCon inlineDataConName
791 repInline Inlinable = dataCon inlinableDataConName
792 repInline spec = notHandled "repInline" (ppr spec)
793
794 repRuleMatch :: RuleMatchInfo -> DsM (Core TH.RuleMatch)
795 repRuleMatch ConLike = dataCon conLikeDataConName
796 repRuleMatch FunLike = dataCon funLikeDataConName
797
798 repPhases :: Activation -> DsM (Core TH.Phases)
799 repPhases (ActiveBefore _ i) = do { MkC arg <- coreIntLit i
800 ; dataCon' beforePhaseDataConName [arg] }
801 repPhases (ActiveAfter _ i) = do { MkC arg <- coreIntLit i
802 ; dataCon' fromPhaseDataConName [arg] }
803 repPhases _ = dataCon allPhasesDataConName
804
805 -------------------------------------------------------
806 -- Types
807 -------------------------------------------------------
808
809 addSimpleTyVarBinds :: [Name] -- the binders to be added
810 -> DsM (Core (TH.Q a)) -- action in the ext env
811 -> DsM (Core (TH.Q a))
812 addSimpleTyVarBinds names thing_inside
813 = do { fresh_names <- mkGenSyms names
814 ; term <- addBinds fresh_names thing_inside
815 ; wrapGenSyms fresh_names term }
816
817 addTyVarBinds :: LHsQTyVars Name -- the binders to be added
818 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a))) -- action in the ext env
819 -> DsM (Core (TH.Q a))
820 -- gensym a list of type variables and enter them into the meta environment;
821 -- the computations passed as the second argument is executed in that extended
822 -- meta environment and gets the *new* names on Core-level as an argument
823
824 addTyVarBinds (HsQTvs { hsq_implicit = imp_tvs, hsq_explicit = exp_tvs }) m
825 = do { fresh_imp_names <- mkGenSyms imp_tvs
826 ; fresh_exp_names <- mkGenSyms (map hsLTyVarName exp_tvs)
827 ; let fresh_names = fresh_imp_names ++ fresh_exp_names
828 ; term <- addBinds fresh_names $
829 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr
830 (exp_tvs `zip` fresh_exp_names)
831 ; m kbs }
832 ; wrapGenSyms fresh_names term }
833 where
834 mk_tv_bndr (tv, (_,v)) = repTyVarBndrWithKind tv (coreVar v)
835
836 addTyClTyVarBinds :: LHsQTyVars Name
837 -> (Core [TH.TyVarBndr] -> DsM (Core (TH.Q a)))
838 -> DsM (Core (TH.Q a))
839
840 -- Used for data/newtype declarations, and family instances,
841 -- so that the nested type variables work right
842 -- instance C (T a) where
843 -- type W (T a) = blah
844 -- The 'a' in the type instance is the one bound by the instance decl
845 addTyClTyVarBinds tvs m
846 = do { let tv_names = hsAllLTyVarNames tvs
847 ; env <- dsGetMetaEnv
848 ; freshNames <- mkGenSyms (filterOut (`elemNameEnv` env) tv_names)
849 -- Make fresh names for the ones that are not already in scope
850 -- This makes things work for family declarations
851
852 ; term <- addBinds freshNames $
853 do { kbs <- repList tyVarBndrTyConName mk_tv_bndr (hsQTvExplicit tvs)
854 ; m kbs }
855
856 ; wrapGenSyms freshNames term }
857 where
858 mk_tv_bndr tv = do { v <- lookupBinder (hsLTyVarName tv)
859 ; repTyVarBndrWithKind tv v }
860
861 -- Produce kinded binder constructors from the Haskell tyvar binders
862 --
863 repTyVarBndrWithKind :: LHsTyVarBndr Name
864 -> Core TH.Name -> DsM (Core TH.TyVarBndr)
865 repTyVarBndrWithKind (L _ (UserTyVar _)) nm
866 = repPlainTV nm
867 repTyVarBndrWithKind (L _ (KindedTyVar _ ki)) nm
868 = repLKind ki >>= repKindedTV nm
869
870 -- | Represent a type variable binder
871 repTyVarBndr :: LHsTyVarBndr Name -> DsM (Core TH.TyVarBndr)
872 repTyVarBndr (L _ (UserTyVar (L _ nm)) )= do { nm' <- lookupBinder nm
873 ; repPlainTV nm' }
874 repTyVarBndr (L _ (KindedTyVar (L _ nm) ki)) = do { nm' <- lookupBinder nm
875 ; ki' <- repLKind ki
876 ; repKindedTV nm' ki' }
877
878 -- represent a type context
879 --
880 repLContext :: LHsContext Name -> DsM (Core TH.CxtQ)
881 repLContext (L _ ctxt) = repContext ctxt
882
883 repContext :: HsContext Name -> DsM (Core TH.CxtQ)
884 repContext ctxt = do preds <- repList typeQTyConName repLTy ctxt
885 repCtxt preds
886
887 repHsSigType :: LHsSigType Name -> DsM (Core TH.TypeQ)
888 repHsSigType (HsIB { hsib_vars = vars
889 , hsib_body = body })
890 | (explicit_tvs, ctxt, ty) <- splitLHsSigmaTy body
891 = addTyVarBinds (HsQTvs { hsq_implicit = []
892 , hsq_explicit = map (noLoc . UserTyVar . noLoc) vars ++
893 explicit_tvs
894 , hsq_dependent = emptyNameSet })
895 $ \ th_tvs ->
896 do { th_ctxt <- repLContext ctxt
897 ; th_ty <- repLTy ty
898 ; if null vars && null explicit_tvs && null (unLoc ctxt)
899 then return th_ty
900 else repTForall th_tvs th_ctxt th_ty }
901
902 repHsPatSynSigType :: LHsSigType Name -> DsM (Core TH.TypeQ)
903 repHsPatSynSigType (HsIB { hsib_vars = implicit_tvs
904 , hsib_body = body })
905 = addTyVarBinds (newTvs (impls ++ univs)) $ \th_univs ->
906 addTyVarBinds (newTvs exis) $ \th_exis ->
907 do { th_reqs <- repLContext reqs
908 ; th_provs <- repLContext provs
909 ; th_ty <- repLTy ty
910 ; repTForall th_univs th_reqs =<< (repTForall th_exis th_provs th_ty) }
911 where
912 impls = map (noLoc . UserTyVar . noLoc) implicit_tvs
913 newTvs tvs = HsQTvs
914 { hsq_implicit = []
915 , hsq_explicit = tvs
916 , hsq_dependent = emptyNameSet }
917 (univs, reqs, exis, provs, ty) = splitLHsPatSynTy body
918
919 repHsSigWcType :: LHsSigWcType Name -> DsM (Core TH.TypeQ)
920 repHsSigWcType (HsWC { hswc_body = sig1 })
921 = repHsSigType sig1
922
923 -- yield the representation of a list of types
924 repLTys :: [LHsType Name] -> DsM [Core TH.TypeQ]
925 repLTys tys = mapM repLTy tys
926
927 -- represent a type
928 repLTy :: LHsType Name -> DsM (Core TH.TypeQ)
929 repLTy (L _ ty) = repTy ty
930
931 repForall :: HsType Name -> DsM (Core TH.TypeQ)
932 -- Arg of repForall is always HsForAllTy or HsQualTy
933 repForall ty
934 | (tvs, ctxt, tau) <- splitLHsSigmaTy (noLoc ty)
935 = addTyVarBinds (HsQTvs { hsq_implicit = [], hsq_explicit = tvs
936 , hsq_dependent = emptyNameSet }) $ \bndrs ->
937 do { ctxt1 <- repLContext ctxt
938 ; ty1 <- repLTy tau
939 ; repTForall bndrs ctxt1 ty1 }
940
941 repTy :: HsType Name -> DsM (Core TH.TypeQ)
942 repTy ty@(HsForAllTy {}) = repForall ty
943 repTy ty@(HsQualTy {}) = repForall ty
944
945 repTy (HsTyVar (L _ n))
946 | isTvOcc occ = do tv1 <- lookupOcc n
947 repTvar tv1
948 | isDataOcc occ = do tc1 <- lookupOcc n
949 repPromotedDataCon tc1
950 | n == eqTyConName = repTequality
951 | otherwise = do tc1 <- lookupOcc n
952 repNamedTyCon tc1
953 where
954 occ = nameOccName n
955
956 repTy (HsAppTy f a) = do
957 f1 <- repLTy f
958 a1 <- repLTy a
959 repTapp f1 a1
960 repTy (HsFunTy f a) = do
961 f1 <- repLTy f
962 a1 <- repLTy a
963 tcon <- repArrowTyCon
964 repTapps tcon [f1, a1]
965 repTy (HsListTy t) = do
966 t1 <- repLTy t
967 tcon <- repListTyCon
968 repTapp tcon t1
969 repTy (HsPArrTy t) = do
970 t1 <- repLTy t
971 tcon <- repTy (HsTyVar (noLoc (tyConName parrTyCon)))
972 repTapp tcon t1
973 repTy (HsTupleTy HsUnboxedTuple tys) = do
974 tys1 <- repLTys tys
975 tcon <- repUnboxedTupleTyCon (length tys)
976 repTapps tcon tys1
977 repTy (HsTupleTy _ tys) = do tys1 <- repLTys tys
978 tcon <- repTupleTyCon (length tys)
979 repTapps tcon tys1
980 repTy (HsOpTy ty1 n ty2) = repLTy ((nlHsTyVar (unLoc n) `nlHsAppTy` ty1)
981 `nlHsAppTy` ty2)
982 repTy (HsParTy t) = repLTy t
983 repTy (HsEqTy t1 t2) = do
984 t1' <- repLTy t1
985 t2' <- repLTy t2
986 eq <- repTequality
987 repTapps eq [t1', t2']
988 repTy (HsKindSig t k) = do
989 t1 <- repLTy t
990 k1 <- repLKind k
991 repTSig t1 k1
992 repTy (HsSpliceTy splice _) = repSplice splice
993 repTy (HsExplicitListTy _ tys) = do
994 tys1 <- repLTys tys
995 repTPromotedList tys1
996 repTy (HsExplicitTupleTy _ tys) = do
997 tys1 <- repLTys tys
998 tcon <- repPromotedTupleTyCon (length tys)
999 repTapps tcon tys1
1000 repTy (HsTyLit lit) = do
1001 lit' <- repTyLit lit
1002 repTLit lit'
1003 repTy (HsWildCardTy (AnonWildCard _)) = repTWildCard
1004
1005 repTy ty = notHandled "Exotic form of type" (ppr ty)
1006
1007 repTyLit :: HsTyLit -> DsM (Core TH.TyLitQ)
1008 repTyLit (HsNumTy _ i) = do iExpr <- mkIntegerExpr i
1009 rep2 numTyLitName [iExpr]
1010 repTyLit (HsStrTy _ s) = do { s' <- mkStringExprFS s
1011 ; rep2 strTyLitName [s']
1012 }
1013
1014 -- represent a kind
1015 --
1016 repLKind :: LHsKind Name -> DsM (Core TH.Kind)
1017 repLKind ki
1018 = do { let (kis, ki') = splitHsFunType ki
1019 ; kis_rep <- mapM repLKind kis
1020 ; ki'_rep <- repNonArrowLKind ki'
1021 ; kcon <- repKArrow
1022 ; let f k1 k2 = repKApp kcon k1 >>= flip repKApp k2
1023 ; foldrM f ki'_rep kis_rep
1024 }
1025
1026 -- | Represent a kind wrapped in a Maybe
1027 repMaybeLKind :: Maybe (LHsKind Name)
1028 -> DsM (Core (Maybe TH.Kind))
1029 repMaybeLKind Nothing =
1030 do { coreNothing kindTyConName }
1031 repMaybeLKind (Just ki) =
1032 do { ki' <- repLKind ki
1033 ; coreJust kindTyConName ki' }
1034
1035 repNonArrowLKind :: LHsKind Name -> DsM (Core TH.Kind)
1036 repNonArrowLKind (L _ ki) = repNonArrowKind ki
1037
1038 repNonArrowKind :: HsKind Name -> DsM (Core TH.Kind)
1039 repNonArrowKind (HsTyVar (L _ name))
1040 | isLiftedTypeKindTyConName name = repKStar
1041 | name `hasKey` constraintKindTyConKey = repKConstraint
1042 | isTvOcc (nameOccName name) = lookupOcc name >>= repKVar
1043 | otherwise = lookupOcc name >>= repKCon
1044 repNonArrowKind (HsAppTy f a) = do { f' <- repLKind f
1045 ; a' <- repLKind a
1046 ; repKApp f' a'
1047 }
1048 repNonArrowKind (HsListTy k) = do { k' <- repLKind k
1049 ; kcon <- repKList
1050 ; repKApp kcon k'
1051 }
1052 repNonArrowKind (HsTupleTy _ ks) = do { ks' <- mapM repLKind ks
1053 ; kcon <- repKTuple (length ks)
1054 ; repKApps kcon ks'
1055 }
1056 repNonArrowKind k = notHandled "Exotic form of kind" (ppr k)
1057
1058 repRole :: Located (Maybe Role) -> DsM (Core TH.Role)
1059 repRole (L _ (Just Nominal)) = rep2 nominalRName []
1060 repRole (L _ (Just Representational)) = rep2 representationalRName []
1061 repRole (L _ (Just Phantom)) = rep2 phantomRName []
1062 repRole (L _ Nothing) = rep2 inferRName []
1063
1064 -----------------------------------------------------------------------------
1065 -- Splices
1066 -----------------------------------------------------------------------------
1067
1068 repSplice :: HsSplice Name -> DsM (Core a)
1069 -- See Note [How brackets and nested splices are handled] in TcSplice
1070 -- We return a CoreExpr of any old type; the context should know
1071 repSplice (HsTypedSplice n _) = rep_splice n
1072 repSplice (HsUntypedSplice n _) = rep_splice n
1073 repSplice (HsQuasiQuote n _ _ _) = rep_splice n
1074 repSplice e@(HsSpliced _ _) = pprPanic "repSplice" (ppr e)
1075
1076 rep_splice :: Name -> DsM (Core a)
1077 rep_splice splice_name
1078 = do { mb_val <- dsLookupMetaEnv splice_name
1079 ; case mb_val of
1080 Just (DsSplice e) -> do { e' <- dsExpr e
1081 ; return (MkC e') }
1082 _ -> pprPanic "HsSplice" (ppr splice_name) }
1083 -- Should not happen; statically checked
1084
1085 -----------------------------------------------------------------------------
1086 -- Expressions
1087 -----------------------------------------------------------------------------
1088
1089 repLEs :: [LHsExpr Name] -> DsM (Core [TH.ExpQ])
1090 repLEs es = repList expQTyConName repLE es
1091
1092 -- FIXME: some of these panics should be converted into proper error messages
1093 -- unless we can make sure that constructs, which are plainly not
1094 -- supported in TH already lead to error messages at an earlier stage
1095 repLE :: LHsExpr Name -> DsM (Core TH.ExpQ)
1096 repLE (L loc e) = putSrcSpanDs loc (repE e)
1097
1098 repE :: HsExpr Name -> DsM (Core TH.ExpQ)
1099 repE (HsVar (L _ x)) =
1100 do { mb_val <- dsLookupMetaEnv x
1101 ; case mb_val of
1102 Nothing -> do { str <- globalVar x
1103 ; repVarOrCon x str }
1104 Just (DsBound y) -> repVarOrCon x (coreVar y)
1105 Just (DsSplice e) -> do { e' <- dsExpr e
1106 ; return (MkC e') } }
1107 repE e@(HsIPVar _) = notHandled "Implicit parameters" (ppr e)
1108 repE e@(HsOverLabel _) = notHandled "Overloaded labels" (ppr e)
1109
1110 repE e@(HsRecFld f) = case f of
1111 Unambiguous _ x -> repE (HsVar (noLoc x))
1112 Ambiguous{} -> notHandled "Ambiguous record selectors" (ppr e)
1113
1114 -- Remember, we're desugaring renamer output here, so
1115 -- HsOverlit can definitely occur
1116 repE (HsOverLit l) = do { a <- repOverloadedLiteral l; repLit a }
1117 repE (HsLit l) = do { a <- repLiteral l; repLit a }
1118 repE (HsLam (MG { mg_alts = L _ [m] })) = repLambda m
1119 repE (HsLamCase (MG { mg_alts = L _ ms }))
1120 = do { ms' <- mapM repMatchTup ms
1121 ; core_ms <- coreList matchQTyConName ms'
1122 ; repLamCase core_ms }
1123 repE (HsApp x y) = do {a <- repLE x; b <- repLE y; repApp a b}
1124
1125 repE (OpApp e1 op _ e2) =
1126 do { arg1 <- repLE e1;
1127 arg2 <- repLE e2;
1128 the_op <- repLE op ;
1129 repInfixApp arg1 the_op arg2 }
1130 repE (NegApp x _) = do
1131 a <- repLE x
1132 negateVar <- lookupOcc negateName >>= repVar
1133 negateVar `repApp` a
1134 repE (HsPar x) = repLE x
1135 repE (SectionL x y) = do { a <- repLE x; b <- repLE y; repSectionL a b }
1136 repE (SectionR x y) = do { a <- repLE x; b <- repLE y; repSectionR a b }
1137 repE (HsCase e (MG { mg_alts = L _ ms }))
1138 = do { arg <- repLE e
1139 ; ms2 <- mapM repMatchTup ms
1140 ; core_ms2 <- coreList matchQTyConName ms2
1141 ; repCaseE arg core_ms2 }
1142 repE (HsIf _ x y z) = do
1143 a <- repLE x
1144 b <- repLE y
1145 c <- repLE z
1146 repCond a b c
1147 repE (HsMultiIf _ alts)
1148 = do { (binds, alts') <- liftM unzip $ mapM repLGRHS alts
1149 ; expr' <- repMultiIf (nonEmptyCoreList alts')
1150 ; wrapGenSyms (concat binds) expr' }
1151 repE (HsLet (L _ bs) e) = do { (ss,ds) <- repBinds bs
1152 ; e2 <- addBinds ss (repLE e)
1153 ; z <- repLetE ds e2
1154 ; wrapGenSyms ss z }
1155
1156 -- FIXME: I haven't got the types here right yet
1157 repE e@(HsDo ctxt (L _ sts) _)
1158 | case ctxt of { DoExpr -> True; GhciStmtCtxt -> True; _ -> False }
1159 = do { (ss,zs) <- repLSts sts;
1160 e' <- repDoE (nonEmptyCoreList zs);
1161 wrapGenSyms ss e' }
1162
1163 | ListComp <- ctxt
1164 = do { (ss,zs) <- repLSts sts;
1165 e' <- repComp (nonEmptyCoreList zs);
1166 wrapGenSyms ss e' }
1167
1168 | otherwise
1169 = notHandled "mdo, monad comprehension and [: :]" (ppr e)
1170
1171 repE (ExplicitList _ _ es) = do { xs <- repLEs es; repListExp xs }
1172 repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
1173 repE e@(ExplicitTuple es boxed)
1174 | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
1175 | isBoxed boxed = do { xs <- repLEs [e | L _ (Present e) <- es]; repTup xs }
1176 | otherwise = do { xs <- repLEs [e | L _ (Present e) <- es]
1177 ; repUnboxedTup xs }
1178
1179 repE (RecordCon { rcon_con_name = c, rcon_flds = flds })
1180 = do { x <- lookupLOcc c;
1181 fs <- repFields flds;
1182 repRecCon x fs }
1183 repE (RecordUpd { rupd_expr = e, rupd_flds = flds })
1184 = do { x <- repLE e;
1185 fs <- repUpdFields flds;
1186 repRecUpd x fs }
1187
1188 repE (ExprWithTySig e ty)
1189 = do { e1 <- repLE e
1190 ; t1 <- repHsSigWcType ty
1191 ; repSigExp e1 t1 }
1192
1193 repE (ArithSeq _ _ aseq) =
1194 case aseq of
1195 From e -> do { ds1 <- repLE e; repFrom ds1 }
1196 FromThen e1 e2 -> do
1197 ds1 <- repLE e1
1198 ds2 <- repLE e2
1199 repFromThen ds1 ds2
1200 FromTo e1 e2 -> do
1201 ds1 <- repLE e1
1202 ds2 <- repLE e2
1203 repFromTo ds1 ds2
1204 FromThenTo e1 e2 e3 -> do
1205 ds1 <- repLE e1
1206 ds2 <- repLE e2
1207 ds3 <- repLE e3
1208 repFromThenTo ds1 ds2 ds3
1209
1210 repE (HsSpliceE splice) = repSplice splice
1211 repE (HsStatic _ e) = repLE e >>= rep2 staticEName . (:[]) . unC
1212 repE (HsUnboundVar uv) = do
1213 occ <- occNameLit (unboundVarOcc uv)
1214 sname <- repNameS occ
1215 repUnboundVar sname
1216
1217 repE e@(PArrSeq {}) = notHandled "Parallel arrays" (ppr e)
1218 repE e@(HsCoreAnn {}) = notHandled "Core annotations" (ppr e)
1219 repE e@(HsSCC {}) = notHandled "Cost centres" (ppr e)
1220 repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
1221 repE e@(HsTcBracketOut {}) = notHandled "TH brackets" (ppr e)
1222 repE e = notHandled "Expression form" (ppr e)
1223
1224 -----------------------------------------------------------------------------
1225 -- Building representations of auxillary structures like Match, Clause, Stmt,
1226
1227 repMatchTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.MatchQ)
1228 repMatchTup (L _ (Match _ [p] _ (GRHSs guards (L _ wheres)))) =
1229 do { ss1 <- mkGenSyms (collectPatBinders p)
1230 ; addBinds ss1 $ do {
1231 ; p1 <- repLP p
1232 ; (ss2,ds) <- repBinds wheres
1233 ; addBinds ss2 $ do {
1234 ; gs <- repGuards guards
1235 ; match <- repMatch p1 gs ds
1236 ; wrapGenSyms (ss1++ss2) match }}}
1237 repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
1238
1239 repClauseTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ClauseQ)
1240 repClauseTup (L _ (Match _ ps _ (GRHSs guards (L _ wheres)))) =
1241 do { ss1 <- mkGenSyms (collectPatsBinders ps)
1242 ; addBinds ss1 $ do {
1243 ps1 <- repLPs ps
1244 ; (ss2,ds) <- repBinds wheres
1245 ; addBinds ss2 $ do {
1246 gs <- repGuards guards
1247 ; clause <- repClause ps1 gs ds
1248 ; wrapGenSyms (ss1++ss2) clause }}}
1249
1250 repGuards :: [LGRHS Name (LHsExpr Name)] -> DsM (Core TH.BodyQ)
1251 repGuards [L _ (GRHS [] e)]
1252 = do {a <- repLE e; repNormal a }
1253 repGuards other
1254 = do { zs <- mapM repLGRHS other
1255 ; let (xs, ys) = unzip zs
1256 ; gd <- repGuarded (nonEmptyCoreList ys)
1257 ; wrapGenSyms (concat xs) gd }
1258
1259 repLGRHS :: LGRHS Name (LHsExpr Name) -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
1260 repLGRHS (L _ (GRHS [L _ (BodyStmt e1 _ _ _)] e2))
1261 = do { guarded <- repLNormalGE e1 e2
1262 ; return ([], guarded) }
1263 repLGRHS (L _ (GRHS ss rhs))
1264 = do { (gs, ss') <- repLSts ss
1265 ; rhs' <- addBinds gs $ repLE rhs
1266 ; guarded <- repPatGE (nonEmptyCoreList ss') rhs'
1267 ; return (gs, guarded) }
1268
1269 repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
1270 repFields (HsRecFields { rec_flds = flds })
1271 = repList fieldExpQTyConName rep_fld flds
1272 where
1273 rep_fld :: LHsRecField Name (LHsExpr Name) -> DsM (Core (TH.Q TH.FieldExp))
1274 rep_fld (L _ fld) = do { fn <- lookupLOcc (hsRecFieldSel fld)
1275 ; e <- repLE (hsRecFieldArg fld)
1276 ; repFieldExp fn e }
1277
1278 repUpdFields :: [LHsRecUpdField Name] -> DsM (Core [TH.Q TH.FieldExp])
1279 repUpdFields = repList fieldExpQTyConName rep_fld
1280 where
1281 rep_fld :: LHsRecUpdField Name -> DsM (Core (TH.Q TH.FieldExp))
1282 rep_fld (L l fld) = case unLoc (hsRecFieldLbl fld) of
1283 Unambiguous _ sel_name -> do { fn <- lookupLOcc (L l sel_name)
1284 ; e <- repLE (hsRecFieldArg fld)
1285 ; repFieldExp fn e }
1286 _ -> notHandled "Ambiguous record updates" (ppr fld)
1287
1288
1289
1290 -----------------------------------------------------------------------------
1291 -- Representing Stmt's is tricky, especially if bound variables
1292 -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |]
1293 -- First gensym new names for every variable in any of the patterns.
1294 -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
1295 -- if variables didn't shaddow, the static gensym wouldn't be necessary
1296 -- and we could reuse the original names (x and x).
1297 --
1298 -- do { x'1 <- gensym "x"
1299 -- ; x'2 <- gensym "x"
1300 -- ; doE [ BindSt (pvar x'1) [| f 1 |]
1301 -- , BindSt (pvar x'2) [| f x |]
1302 -- , NoBindSt [| g x |]
1303 -- ]
1304 -- }
1305
1306 -- The strategy is to translate a whole list of do-bindings by building a
1307 -- bigger environment, and a bigger set of meta bindings
1308 -- (like: x'1 <- gensym "x" ) and then combining these with the translations
1309 -- of the expressions within the Do
1310
1311 -----------------------------------------------------------------------------
1312 -- The helper function repSts computes the translation of each sub expression
1313 -- and a bunch of prefix bindings denoting the dynamic renaming.
1314
1315 repLSts :: [LStmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1316 repLSts stmts = repSts (map unLoc stmts)
1317
1318 repSts :: [Stmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1319 repSts (BindStmt p e _ _ _ : ss) =
1320 do { e2 <- repLE e
1321 ; ss1 <- mkGenSyms (collectPatBinders p)
1322 ; addBinds ss1 $ do {
1323 ; p1 <- repLP p;
1324 ; (ss2,zs) <- repSts ss
1325 ; z <- repBindSt p1 e2
1326 ; return (ss1++ss2, z : zs) }}
1327 repSts (LetStmt (L _ bs) : ss) =
1328 do { (ss1,ds) <- repBinds bs
1329 ; z <- repLetSt ds
1330 ; (ss2,zs) <- addBinds ss1 (repSts ss)
1331 ; return (ss1++ss2, z : zs) }
1332 repSts (BodyStmt e _ _ _ : ss) =
1333 do { e2 <- repLE e
1334 ; z <- repNoBindSt e2
1335 ; (ss2,zs) <- repSts ss
1336 ; return (ss2, z : zs) }
1337 repSts (ParStmt stmt_blocks _ _ _ : ss) =
1338 do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks
1339 ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1
1340 ss1 = concat ss_s
1341 ; z <- repParSt stmt_blocks2
1342 ; (ss2, zs) <- addBinds ss1 (repSts ss)
1343 ; return (ss1++ss2, z : zs) }
1344 where
1345 rep_stmt_block :: ParStmtBlock Name Name -> DsM ([GenSymBind], Core [TH.StmtQ])
1346 rep_stmt_block (ParStmtBlock stmts _ _) =
1347 do { (ss1, zs) <- repSts (map unLoc stmts)
1348 ; zs1 <- coreList stmtQTyConName zs
1349 ; return (ss1, zs1) }
1350 repSts [LastStmt e _ _]
1351 = do { e2 <- repLE e
1352 ; z <- repNoBindSt e2
1353 ; return ([], [z]) }
1354 repSts [] = return ([],[])
1355 repSts other = notHandled "Exotic statement" (ppr other)
1356
1357
1358 -----------------------------------------------------------
1359 -- Bindings
1360 -----------------------------------------------------------
1361
1362 repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ])
1363 repBinds EmptyLocalBinds
1364 = do { core_list <- coreList decQTyConName []
1365 ; return ([], core_list) }
1366
1367 repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
1368
1369 repBinds (HsValBinds decs)
1370 = do { let { bndrs = hsSigTvBinders decs ++ collectHsValBinders decs }
1371 -- No need to worrry about detailed scopes within
1372 -- the binding group, because we are talking Names
1373 -- here, so we can safely treat it as a mutually
1374 -- recursive group
1375 -- For hsSigTvBinders see Note [Scoped type variables in bindings]
1376 ; ss <- mkGenSyms bndrs
1377 ; prs <- addBinds ss (rep_val_binds decs)
1378 ; core_list <- coreList decQTyConName
1379 (de_loc (sort_by_loc prs))
1380 ; return (ss, core_list) }
1381
1382 rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1383 -- Assumes: all the binders of the binding are alrady in the meta-env
1384 rep_val_binds (ValBindsOut binds sigs)
1385 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
1386 ; core2 <- rep_sigs' sigs
1387 ; return (core1 ++ core2) }
1388 rep_val_binds (ValBindsIn _ _)
1389 = panic "rep_val_binds: ValBindsIn"
1390
1391 rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
1392 rep_binds binds = do { binds_w_locs <- rep_binds' binds
1393 ; return (de_loc (sort_by_loc binds_w_locs)) }
1394
1395 rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1396 rep_binds' = mapM rep_bind . bagToList
1397
1398 rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
1399 -- Assumes: all the binders of the binding are alrady in the meta-env
1400
1401 -- Note GHC treats declarations of a variable (not a pattern)
1402 -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match
1403 -- with an empty list of patterns
1404 rep_bind (L loc (FunBind
1405 { fun_id = fn,
1406 fun_matches = MG { mg_alts
1407 = L _ [L _ (Match _ [] _
1408 (GRHSs guards (L _ wheres)))] } }))
1409 = do { (ss,wherecore) <- repBinds wheres
1410 ; guardcore <- addBinds ss (repGuards guards)
1411 ; fn' <- lookupLBinder fn
1412 ; p <- repPvar fn'
1413 ; ans <- repVal p guardcore wherecore
1414 ; ans' <- wrapGenSyms ss ans
1415 ; return (loc, ans') }
1416
1417 rep_bind (L loc (FunBind { fun_id = fn
1418 , fun_matches = MG { mg_alts = L _ ms } }))
1419 = do { ms1 <- mapM repClauseTup ms
1420 ; fn' <- lookupLBinder fn
1421 ; ans <- repFun fn' (nonEmptyCoreList ms1)
1422 ; return (loc, ans) }
1423
1424 rep_bind (L loc (PatBind { pat_lhs = pat
1425 , pat_rhs = GRHSs guards (L _ wheres) }))
1426 = do { patcore <- repLP pat
1427 ; (ss,wherecore) <- repBinds wheres
1428 ; guardcore <- addBinds ss (repGuards guards)
1429 ; ans <- repVal patcore guardcore wherecore
1430 ; ans' <- wrapGenSyms ss ans
1431 ; return (loc, ans') }
1432
1433 rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1434 = do { v' <- lookupBinder v
1435 ; e2 <- repLE e
1436 ; x <- repNormal e2
1437 ; patcore <- repPvar v'
1438 ; empty_decls <- coreList decQTyConName []
1439 ; ans <- repVal patcore x empty_decls
1440 ; return (srcLocSpan (getSrcLoc v), ans) }
1441
1442 rep_bind (L _ (AbsBinds {})) = panic "rep_bind: AbsBinds"
1443 rep_bind (L _ (AbsBindsSig {})) = panic "rep_bind: AbsBindsSig"
1444 rep_bind (L loc (PatSynBind (PSB { psb_id = syn
1445 , psb_fvs = _fvs
1446 , psb_args = args
1447 , psb_def = pat
1448 , psb_dir = dir })))
1449 = do { syn' <- lookupLBinder syn
1450 ; dir' <- repPatSynDir dir
1451 ; ss <- mkGenArgSyms args
1452 ; patSynD' <- addBinds ss (
1453 do { args' <- repPatSynArgs args
1454 ; pat' <- repLP pat
1455 ; repPatSynD syn' args' dir' pat' })
1456 ; patSynD'' <- wrapGenArgSyms args ss patSynD'
1457 ; return (loc, patSynD'') }
1458 where
1459 mkGenArgSyms :: HsPatSynDetails (Located Name) -> DsM [GenSymBind]
1460 -- for Record Pattern Synonyms we want to conflate the selector
1461 -- and the pattern-only names in order to provide a nicer TH
1462 -- API. Whereas inside GHC, record pattern synonym selectors and
1463 -- their pattern-only bound right hand sides have different names,
1464 -- we want to treat them the same in TH. This is the reason why we
1465 -- need an adjusted mkGenArgSyms in the `RecordPatSyn` case below.
1466 mkGenArgSyms (PrefixPatSyn args) = mkGenSyms (map unLoc args)
1467 mkGenArgSyms (InfixPatSyn arg1 arg2) = mkGenSyms [unLoc arg1, unLoc arg2]
1468 mkGenArgSyms (RecordPatSyn fields)
1469 = do { let pats = map (unLoc . recordPatSynPatVar) fields
1470 sels = map (unLoc . recordPatSynSelectorId) fields
1471 ; ss <- mkGenSyms sels
1472 ; return $ replaceNames (zip sels pats) ss }
1473
1474 replaceNames selsPats genSyms
1475 = [ (pat, id) | (sel, id) <- genSyms, (sel', pat) <- selsPats
1476 , sel == sel' ]
1477
1478 wrapGenArgSyms :: HsPatSynDetails (Located Name)
1479 -> [GenSymBind] -> Core TH.DecQ -> DsM (Core TH.DecQ)
1480 wrapGenArgSyms (RecordPatSyn _) _ dec = return dec
1481 wrapGenArgSyms _ ss dec = wrapGenSyms ss dec
1482
1483 repPatSynD :: Core TH.Name
1484 -> Core TH.PatSynArgsQ
1485 -> Core TH.PatSynDirQ
1486 -> Core TH.PatQ
1487 -> DsM (Core TH.DecQ)
1488 repPatSynD (MkC syn) (MkC args) (MkC dir) (MkC pat)
1489 = rep2 patSynDName [syn, args, dir, pat]
1490
1491 repPatSynArgs :: HsPatSynDetails (Located Name) -> DsM (Core TH.PatSynArgsQ)
1492 repPatSynArgs (PrefixPatSyn args)
1493 = do { args' <- repList nameTyConName lookupLOcc args
1494 ; repPrefixPatSynArgs args' }
1495 repPatSynArgs (InfixPatSyn arg1 arg2)
1496 = do { arg1' <- lookupLOcc arg1
1497 ; arg2' <- lookupLOcc arg2
1498 ; repInfixPatSynArgs arg1' arg2' }
1499 repPatSynArgs (RecordPatSyn fields)
1500 = do { sels' <- repList nameTyConName lookupLOcc sels
1501 ; repRecordPatSynArgs sels' }
1502 where sels = map recordPatSynSelectorId fields
1503
1504 repPrefixPatSynArgs :: Core [TH.Name] -> DsM (Core TH.PatSynArgsQ)
1505 repPrefixPatSynArgs (MkC nms) = rep2 prefixPatSynName [nms]
1506
1507 repInfixPatSynArgs :: Core TH.Name -> Core TH.Name -> DsM (Core TH.PatSynArgsQ)
1508 repInfixPatSynArgs (MkC nm1) (MkC nm2) = rep2 infixPatSynName [nm1, nm2]
1509
1510 repRecordPatSynArgs :: Core [TH.Name]
1511 -> DsM (Core TH.PatSynArgsQ)
1512 repRecordPatSynArgs (MkC sels) = rep2 recordPatSynName [sels]
1513
1514 repPatSynDir :: HsPatSynDir Name -> DsM (Core TH.PatSynDirQ)
1515 repPatSynDir Unidirectional = rep2 unidirPatSynName []
1516 repPatSynDir ImplicitBidirectional = rep2 implBidirPatSynName []
1517 repPatSynDir (ExplicitBidirectional (MG { mg_alts = L _ clauses }))
1518 = do { clauses' <- mapM repClauseTup clauses
1519 ; repExplBidirPatSynDir (nonEmptyCoreList clauses') }
1520
1521 repExplBidirPatSynDir :: Core [TH.ClauseQ] -> DsM (Core TH.PatSynDirQ)
1522 repExplBidirPatSynDir (MkC cls) = rep2 explBidirPatSynName [cls]
1523
1524
1525 -----------------------------------------------------------------------------
1526 -- Since everything in a Bind is mutually recursive we need rename all
1527 -- all the variables simultaneously. For example:
1528 -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to
1529 -- do { f'1 <- gensym "f"
1530 -- ; g'2 <- gensym "g"
1531 -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]},
1532 -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]}
1533 -- ]}
1534 -- This requires collecting the bindings (f'1 <- gensym "f"), and the
1535 -- environment ( f |-> f'1 ) from each binding, and then unioning them
1536 -- together. As we do this we collect GenSymBinds's which represent the renamed
1537 -- variables bound by the Bindings. In order not to lose track of these
1538 -- representations we build a shadow datatype MB with the same structure as
1539 -- MonoBinds, but which has slots for the representations
1540
1541
1542 -----------------------------------------------------------------------------
1543 -- GHC allows a more general form of lambda abstraction than specified
1544 -- by Haskell 98. In particular it allows guarded lambda's like :
1545 -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in
1546 -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like
1547 -- (\ p1 .. pn -> exp) by causing an error.
1548
1549 repLambda :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ExpQ)
1550 repLambda (L _ (Match _ ps _ (GRHSs [L _ (GRHS [] e)] (L _ EmptyLocalBinds))))
1551 = do { let bndrs = collectPatsBinders ps ;
1552 ; ss <- mkGenSyms bndrs
1553 ; lam <- addBinds ss (
1554 do { xs <- repLPs ps; body <- repLE e; repLam xs body })
1555 ; wrapGenSyms ss lam }
1556
1557 repLambda (L _ m) = notHandled "Guarded labmdas" (pprMatch m)
1558
1559
1560 -----------------------------------------------------------------------------
1561 -- Patterns
1562 -- repP deals with patterns. It assumes that we have already
1563 -- walked over the pattern(s) once to collect the binders, and
1564 -- have extended the environment. So every pattern-bound
1565 -- variable should already appear in the environment.
1566
1567 -- Process a list of patterns
1568 repLPs :: [LPat Name] -> DsM (Core [TH.PatQ])
1569 repLPs ps = repList patQTyConName repLP ps
1570
1571 repLP :: LPat Name -> DsM (Core TH.PatQ)
1572 repLP (L _ p) = repP p
1573
1574 repP :: Pat Name -> DsM (Core TH.PatQ)
1575 repP (WildPat _) = repPwild
1576 repP (LitPat l) = do { l2 <- repLiteral l; repPlit l2 }
1577 repP (VarPat (L _ x)) = do { x' <- lookupBinder x; repPvar x' }
1578 repP (LazyPat p) = do { p1 <- repLP p; repPtilde p1 }
1579 repP (BangPat p) = do { p1 <- repLP p; repPbang p1 }
1580 repP (AsPat x p) = do { x' <- lookupLBinder x; p1 <- repLP p; repPaspat x' p1 }
1581 repP (ParPat p) = repLP p
1582 repP (ListPat ps _ Nothing) = do { qs <- repLPs ps; repPlist qs }
1583 repP (ListPat ps ty1 (Just (_,e))) = do { p <- repP (ListPat ps ty1 Nothing); e' <- repE (syn_expr e); repPview e' p}
1584 repP (TuplePat ps boxed _)
1585 | isBoxed boxed = do { qs <- repLPs ps; repPtup qs }
1586 | otherwise = do { qs <- repLPs ps; repPunboxedTup qs }
1587 repP (ConPatIn dc details)
1588 = do { con_str <- lookupLOcc dc
1589 ; case details of
1590 PrefixCon ps -> do { qs <- repLPs ps; repPcon con_str qs }
1591 RecCon rec -> do { fps <- repList fieldPatQTyConName rep_fld (rec_flds rec)
1592 ; repPrec con_str fps }
1593 InfixCon p1 p2 -> do { p1' <- repLP p1;
1594 p2' <- repLP p2;
1595 repPinfix p1' con_str p2' }
1596 }
1597 where
1598 rep_fld :: LHsRecField Name (LPat Name) -> DsM (Core (TH.Name,TH.PatQ))
1599 rep_fld (L _ fld) = do { MkC v <- lookupLOcc (hsRecFieldSel fld)
1600 ; MkC p <- repLP (hsRecFieldArg fld)
1601 ; rep2 fieldPatName [v,p] }
1602
1603 repP (NPat (L _ l) Nothing _ _) = do { a <- repOverloadedLiteral l; repPlit a }
1604 repP (ViewPat e p _) = do { e' <- repLE e; p' <- repLP p; repPview e' p' }
1605 repP p@(NPat _ (Just _) _ _) = notHandled "Negative overloaded patterns" (ppr p)
1606 repP p@(SigPatIn {}) = notHandled "Type signatures in patterns" (ppr p)
1607 -- The problem is to do with scoped type variables.
1608 -- To implement them, we have to implement the scoping rules
1609 -- here in DsMeta, and I don't want to do that today!
1610 -- do { p' <- repLP p; t' <- repLTy t; repPsig p' t' }
1611 -- repPsig :: Core TH.PatQ -> Core TH.TypeQ -> DsM (Core TH.PatQ)
1612 -- repPsig (MkC p) (MkC t) = rep2 sigPName [p, t]
1613
1614 repP (SplicePat splice) = repSplice splice
1615
1616 repP other = notHandled "Exotic pattern" (ppr other)
1617
1618 ----------------------------------------------------------
1619 -- Declaration ordering helpers
1620
1621 sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)]
1622 sort_by_loc xs = sortBy comp xs
1623 where comp x y = compare (fst x) (fst y)
1624
1625 de_loc :: [(a, b)] -> [b]
1626 de_loc = map snd
1627
1628 ----------------------------------------------------------
1629 -- The meta-environment
1630
1631 -- A name/identifier association for fresh names of locally bound entities
1632 type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id
1633 -- I.e. (x, x_id) means
1634 -- let x_id = gensym "x" in ...
1635
1636 -- Generate a fresh name for a locally bound entity
1637
1638 mkGenSyms :: [Name] -> DsM [GenSymBind]
1639 -- We can use the existing name. For example:
1640 -- [| \x_77 -> x_77 + x_77 |]
1641 -- desugars to
1642 -- do { x_77 <- genSym "x"; .... }
1643 -- We use the same x_77 in the desugared program, but with the type Bndr
1644 -- instead of Int
1645 --
1646 -- We do make it an Internal name, though (hence localiseName)
1647 --
1648 -- Nevertheless, it's monadic because we have to generate nameTy
1649 mkGenSyms ns = do { var_ty <- lookupType nameTyConName
1650 ; return [(nm, mkLocalId (localiseName nm) var_ty) | nm <- ns] }
1651
1652
1653 addBinds :: [GenSymBind] -> DsM a -> DsM a
1654 -- Add a list of fresh names for locally bound entities to the
1655 -- meta environment (which is part of the state carried around
1656 -- by the desugarer monad)
1657 addBinds bs m = dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs]) m
1658
1659 -- Look up a locally bound name
1660 --
1661 lookupLBinder :: Located Name -> DsM (Core TH.Name)
1662 lookupLBinder (L _ n) = lookupBinder n
1663
1664 lookupBinder :: Name -> DsM (Core TH.Name)
1665 lookupBinder = lookupOcc
1666 -- Binders are brought into scope before the pattern or what-not is
1667 -- desugared. Moreover, in instance declaration the binder of a method
1668 -- will be the selector Id and hence a global; so we need the
1669 -- globalVar case of lookupOcc
1670
1671 -- Look up a name that is either locally bound or a global name
1672 --
1673 -- * If it is a global name, generate the "original name" representation (ie,
1674 -- the <module>:<name> form) for the associated entity
1675 --
1676 lookupLOcc :: Located Name -> DsM (Core TH.Name)
1677 -- Lookup an occurrence; it can't be a splice.
1678 -- Use the in-scope bindings if they exist
1679 lookupLOcc (L _ n) = lookupOcc n
1680
1681 lookupOcc :: Name -> DsM (Core TH.Name)
1682 lookupOcc n
1683 = do { mb_val <- dsLookupMetaEnv n ;
1684 case mb_val of
1685 Nothing -> globalVar n
1686 Just (DsBound x) -> return (coreVar x)
1687 Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n)
1688 }
1689
1690 globalVar :: Name -> DsM (Core TH.Name)
1691 -- Not bound by the meta-env
1692 -- Could be top-level; or could be local
1693 -- f x = $(g [| x |])
1694 -- Here the x will be local
1695 globalVar name
1696 | isExternalName name
1697 = do { MkC mod <- coreStringLit name_mod
1698 ; MkC pkg <- coreStringLit name_pkg
1699 ; MkC occ <- nameLit name
1700 ; rep2 mk_varg [pkg,mod,occ] }
1701 | otherwise
1702 = do { MkC occ <- nameLit name
1703 ; MkC uni <- coreIntLit (getKey (getUnique name))
1704 ; rep2 mkNameLName [occ,uni] }
1705 where
1706 mod = ASSERT( isExternalName name) nameModule name
1707 name_mod = moduleNameString (moduleName mod)
1708 name_pkg = unitIdString (moduleUnitId mod)
1709 name_occ = nameOccName name
1710 mk_varg | OccName.isDataOcc name_occ = mkNameG_dName
1711 | OccName.isVarOcc name_occ = mkNameG_vName
1712 | OccName.isTcOcc name_occ = mkNameG_tcName
1713 | otherwise = pprPanic "DsMeta.globalVar" (ppr name)
1714
1715 lookupType :: Name -- Name of type constructor (e.g. TH.ExpQ)
1716 -> DsM Type -- The type
1717 lookupType tc_name = do { tc <- dsLookupTyCon tc_name ;
1718 return (mkTyConApp tc []) }
1719
1720 wrapGenSyms :: [GenSymBind]
1721 -> Core (TH.Q a) -> DsM (Core (TH.Q a))
1722 -- wrapGenSyms [(nm1,id1), (nm2,id2)] y
1723 -- --> bindQ (gensym nm1) (\ id1 ->
1724 -- bindQ (gensym nm2 (\ id2 ->
1725 -- y))
1726
1727 wrapGenSyms binds body@(MkC b)
1728 = do { var_ty <- lookupType nameTyConName
1729 ; go var_ty binds }
1730 where
1731 [elt_ty] = tcTyConAppArgs (exprType b)
1732 -- b :: Q a, so we can get the type 'a' by looking at the
1733 -- argument type. NB: this relies on Q being a data/newtype,
1734 -- not a type synonym
1735
1736 go _ [] = return body
1737 go var_ty ((name,id) : binds)
1738 = do { MkC body' <- go var_ty binds
1739 ; lit_str <- nameLit name
1740 ; gensym_app <- repGensym lit_str
1741 ; repBindQ var_ty elt_ty
1742 gensym_app (MkC (Lam id body')) }
1743
1744 nameLit :: Name -> DsM (Core String)
1745 nameLit n = coreStringLit (occNameString (nameOccName n))
1746
1747 occNameLit :: OccName -> DsM (Core String)
1748 occNameLit name = coreStringLit (occNameString name)
1749
1750
1751 -- %*********************************************************************
1752 -- %* *
1753 -- Constructing code
1754 -- %* *
1755 -- %*********************************************************************
1756
1757 -----------------------------------------------------------------------------
1758 -- PHANTOM TYPES for consistency. In order to make sure we do this correct
1759 -- we invent a new datatype which uses phantom types.
1760
1761 newtype Core a = MkC CoreExpr
1762 unC :: Core a -> CoreExpr
1763 unC (MkC x) = x
1764
1765 rep2 :: Name -> [ CoreExpr ] -> DsM (Core a)
1766 rep2 n xs = do { id <- dsLookupGlobalId n
1767 ; return (MkC (foldl App (Var id) xs)) }
1768
1769 dataCon' :: Name -> [CoreExpr] -> DsM (Core a)
1770 dataCon' n args = do { id <- dsLookupDataCon n
1771 ; return $ MkC $ mkCoreConApps id args }
1772
1773 dataCon :: Name -> DsM (Core a)
1774 dataCon n = dataCon' n []
1775
1776
1777 -- %*********************************************************************
1778 -- %* *
1779 -- The 'smart constructors'
1780 -- %* *
1781 -- %*********************************************************************
1782
1783 --------------- Patterns -----------------
1784 repPlit :: Core TH.Lit -> DsM (Core TH.PatQ)
1785 repPlit (MkC l) = rep2 litPName [l]
1786
1787 repPvar :: Core TH.Name -> DsM (Core TH.PatQ)
1788 repPvar (MkC s) = rep2 varPName [s]
1789
1790 repPtup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1791 repPtup (MkC ps) = rep2 tupPName [ps]
1792
1793 repPunboxedTup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1794 repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps]
1795
1796 repPcon :: Core TH.Name -> Core [TH.PatQ] -> DsM (Core TH.PatQ)
1797 repPcon (MkC s) (MkC ps) = rep2 conPName [s, ps]
1798
1799 repPrec :: Core TH.Name -> Core [(TH.Name,TH.PatQ)] -> DsM (Core TH.PatQ)
1800 repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps]
1801
1802 repPinfix :: Core TH.PatQ -> Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1803 repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2]
1804
1805 repPtilde :: Core TH.PatQ -> DsM (Core TH.PatQ)
1806 repPtilde (MkC p) = rep2 tildePName [p]
1807
1808 repPbang :: Core TH.PatQ -> DsM (Core TH.PatQ)
1809 repPbang (MkC p) = rep2 bangPName [p]
1810
1811 repPaspat :: Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1812 repPaspat (MkC s) (MkC p) = rep2 asPName [s, p]
1813
1814 repPwild :: DsM (Core TH.PatQ)
1815 repPwild = rep2 wildPName []
1816
1817 repPlist :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1818 repPlist (MkC ps) = rep2 listPName [ps]
1819
1820 repPview :: Core TH.ExpQ -> Core TH.PatQ -> DsM (Core TH.PatQ)
1821 repPview (MkC e) (MkC p) = rep2 viewPName [e,p]
1822
1823 --------------- Expressions -----------------
1824 repVarOrCon :: Name -> Core TH.Name -> DsM (Core TH.ExpQ)
1825 repVarOrCon vc str | isDataOcc (nameOccName vc) = repCon str
1826 | otherwise = repVar str
1827
1828 repVar :: Core TH.Name -> DsM (Core TH.ExpQ)
1829 repVar (MkC s) = rep2 varEName [s]
1830
1831 repCon :: Core TH.Name -> DsM (Core TH.ExpQ)
1832 repCon (MkC s) = rep2 conEName [s]
1833
1834 repLit :: Core TH.Lit -> DsM (Core TH.ExpQ)
1835 repLit (MkC c) = rep2 litEName [c]
1836
1837 repApp :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1838 repApp (MkC x) (MkC y) = rep2 appEName [x,y]
1839
1840 repLam :: Core [TH.PatQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1841 repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e]
1842
1843 repLamCase :: Core [TH.MatchQ] -> DsM (Core TH.ExpQ)
1844 repLamCase (MkC ms) = rep2 lamCaseEName [ms]
1845
1846 repTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1847 repTup (MkC es) = rep2 tupEName [es]
1848
1849 repUnboxedTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1850 repUnboxedTup (MkC es) = rep2 unboxedTupEName [es]
1851
1852 repCond :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1853 repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z]
1854
1855 repMultiIf :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.ExpQ)
1856 repMultiIf (MkC alts) = rep2 multiIfEName [alts]
1857
1858 repLetE :: Core [TH.DecQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1859 repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e]
1860
1861 repCaseE :: Core TH.ExpQ -> Core [TH.MatchQ] -> DsM( Core TH.ExpQ)
1862 repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms]
1863
1864 repDoE :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1865 repDoE (MkC ss) = rep2 doEName [ss]
1866
1867 repComp :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1868 repComp (MkC ss) = rep2 compEName [ss]
1869
1870 repListExp :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1871 repListExp (MkC es) = rep2 listEName [es]
1872
1873 repSigExp :: Core TH.ExpQ -> Core TH.TypeQ -> DsM (Core TH.ExpQ)
1874 repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t]
1875
1876 repRecCon :: Core TH.Name -> Core [TH.Q TH.FieldExp]-> DsM (Core TH.ExpQ)
1877 repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs]
1878
1879 repRecUpd :: Core TH.ExpQ -> Core [TH.Q TH.FieldExp] -> DsM (Core TH.ExpQ)
1880 repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs]
1881
1882 repFieldExp :: Core TH.Name -> Core TH.ExpQ -> DsM (Core (TH.Q TH.FieldExp))
1883 repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x]
1884
1885 repInfixApp :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1886 repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z]
1887
1888 repSectionL :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1889 repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y]
1890
1891 repSectionR :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1892 repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y]
1893
1894 ------------ Right hand sides (guarded expressions) ----
1895 repGuarded :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.BodyQ)
1896 repGuarded (MkC pairs) = rep2 guardedBName [pairs]
1897
1898 repNormal :: Core TH.ExpQ -> DsM (Core TH.BodyQ)
1899 repNormal (MkC e) = rep2 normalBName [e]
1900
1901 ------------ Guards ----
1902 repLNormalGE :: LHsExpr Name -> LHsExpr Name -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1903 repLNormalGE g e = do g' <- repLE g
1904 e' <- repLE e
1905 repNormalGE g' e'
1906
1907 repNormalGE :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1908 repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e]
1909
1910 repPatGE :: Core [TH.StmtQ] -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1911 repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e]
1912
1913 ------------- Stmts -------------------
1914 repBindSt :: Core TH.PatQ -> Core TH.ExpQ -> DsM (Core TH.StmtQ)
1915 repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e]
1916
1917 repLetSt :: Core [TH.DecQ] -> DsM (Core TH.StmtQ)
1918 repLetSt (MkC ds) = rep2 letSName [ds]
1919
1920 repNoBindSt :: Core TH.ExpQ -> DsM (Core TH.StmtQ)
1921 repNoBindSt (MkC e) = rep2 noBindSName [e]
1922
1923 repParSt :: Core [[TH.StmtQ]] -> DsM (Core TH.StmtQ)
1924 repParSt (MkC sss) = rep2 parSName [sss]
1925
1926 -------------- Range (Arithmetic sequences) -----------
1927 repFrom :: Core TH.ExpQ -> DsM (Core TH.ExpQ)
1928 repFrom (MkC x) = rep2 fromEName [x]
1929
1930 repFromThen :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1931 repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y]
1932
1933 repFromTo :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1934 repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y]
1935
1936 repFromThenTo :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1937 repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z]
1938
1939 ------------ Match and Clause Tuples -----------
1940 repMatch :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.MatchQ)
1941 repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds]
1942
1943 repClause :: Core [TH.PatQ] -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.ClauseQ)
1944 repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds]
1945
1946 -------------- Dec -----------------------------
1947 repVal :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1948 repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds]
1949
1950 repFun :: Core TH.Name -> Core [TH.ClauseQ] -> DsM (Core TH.DecQ)
1951 repFun (MkC nm) (MkC b) = rep2 funDName [nm, b]
1952
1953 repData :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1954 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1955 -> Core [TH.ConQ] -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1956 repData (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC cons) (MkC derivs)
1957 = rep2 dataDName [cxt, nm, tvs, ksig, cons, derivs]
1958 repData (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC cons)
1959 (MkC derivs)
1960 = rep2 dataInstDName [cxt, nm, tys, ksig, cons, derivs]
1961
1962 repNewtype :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1963 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1964 -> Core TH.ConQ -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1965 repNewtype (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC con)
1966 (MkC derivs)
1967 = rep2 newtypeDName [cxt, nm, tvs, ksig, con, derivs]
1968 repNewtype (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC con)
1969 (MkC derivs)
1970 = rep2 newtypeInstDName [cxt, nm, tys, ksig, con, derivs]
1971
1972 repTySyn :: Core TH.Name -> Core [TH.TyVarBndr]
1973 -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1974 repTySyn (MkC nm) (MkC tvs) (MkC rhs)
1975 = rep2 tySynDName [nm, tvs, rhs]
1976
1977 repInst :: Core (Maybe TH.Overlap) ->
1978 Core TH.CxtQ -> Core TH.TypeQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1979 repInst (MkC o) (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceWithOverlapDName
1980 [o, cxt, ty, ds]
1981
1982 repOverlap :: Maybe OverlapMode -> DsM (Core (Maybe TH.Overlap))
1983 repOverlap mb =
1984 case mb of
1985 Nothing -> nothing
1986 Just o ->
1987 case o of
1988 NoOverlap _ -> nothing
1989 Overlappable _ -> just =<< dataCon overlappableDataConName
1990 Overlapping _ -> just =<< dataCon overlappingDataConName
1991 Overlaps _ -> just =<< dataCon overlapsDataConName
1992 Incoherent _ -> just =<< dataCon incoherentDataConName
1993 where
1994 nothing = coreNothing overlapTyConName
1995 just = coreJust overlapTyConName
1996
1997
1998 repClass :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1999 -> Core [TH.FunDep] -> Core [TH.DecQ]
2000 -> DsM (Core TH.DecQ)
2001 repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds)
2002 = rep2 classDName [cxt, cls, tvs, fds, ds]
2003
2004 repDeriv :: Core TH.CxtQ -> Core TH.TypeQ -> DsM (Core TH.DecQ)
2005 repDeriv (MkC cxt) (MkC ty) = rep2 standaloneDerivDName [cxt, ty]
2006
2007 repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch
2008 -> Core TH.Phases -> DsM (Core TH.DecQ)
2009 repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases)
2010 = rep2 pragInlDName [nm, inline, rm, phases]
2011
2012 repPragSpec :: Core TH.Name -> Core TH.TypeQ -> Core TH.Phases
2013 -> DsM (Core TH.DecQ)
2014 repPragSpec (MkC nm) (MkC ty) (MkC phases)
2015 = rep2 pragSpecDName [nm, ty, phases]
2016
2017 repPragSpecInl :: Core TH.Name -> Core TH.TypeQ -> Core TH.Inline
2018 -> Core TH.Phases -> DsM (Core TH.DecQ)
2019 repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases)
2020 = rep2 pragSpecInlDName [nm, ty, inline, phases]
2021
2022 repPragSpecInst :: Core TH.TypeQ -> DsM (Core TH.DecQ)
2023 repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty]
2024
2025 repPragRule :: Core String -> Core [TH.RuleBndrQ] -> Core TH.ExpQ
2026 -> Core TH.ExpQ -> Core TH.Phases -> DsM (Core TH.DecQ)
2027 repPragRule (MkC nm) (MkC bndrs) (MkC lhs) (MkC rhs) (MkC phases)
2028 = rep2 pragRuleDName [nm, bndrs, lhs, rhs, phases]
2029
2030 repPragAnn :: Core TH.AnnTarget -> Core TH.ExpQ -> DsM (Core TH.DecQ)
2031 repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e]
2032
2033 repTySynInst :: Core TH.Name -> Core TH.TySynEqnQ -> DsM (Core TH.DecQ)
2034 repTySynInst (MkC nm) (MkC eqn)
2035 = rep2 tySynInstDName [nm, eqn]
2036
2037 repDataFamilyD :: Core TH.Name -> Core [TH.TyVarBndr]
2038 -> Core (Maybe TH.Kind) -> DsM (Core TH.DecQ)
2039 repDataFamilyD (MkC nm) (MkC tvs) (MkC kind)
2040 = rep2 dataFamilyDName [nm, tvs, kind]
2041
2042 repOpenFamilyD :: Core TH.Name
2043 -> Core [TH.TyVarBndr]
2044 -> Core TH.FamilyResultSig
2045 -> Core (Maybe TH.InjectivityAnn)
2046 -> DsM (Core TH.DecQ)
2047 repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj)
2048 = rep2 openTypeFamilyDName [nm, tvs, result, inj]
2049
2050 repClosedFamilyD :: Core TH.Name
2051 -> Core [TH.TyVarBndr]
2052 -> Core TH.FamilyResultSig
2053 -> Core (Maybe TH.InjectivityAnn)
2054 -> Core [TH.TySynEqnQ]
2055 -> DsM (Core TH.DecQ)
2056 repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns)
2057 = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns]
2058
2059 repTySynEqn :: Core [TH.TypeQ] -> Core TH.TypeQ -> DsM (Core TH.TySynEqnQ)
2060 repTySynEqn (MkC lhs) (MkC rhs)
2061 = rep2 tySynEqnName [lhs, rhs]
2062
2063 repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> DsM (Core TH.DecQ)
2064 repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles]
2065
2066 repFunDep :: Core [TH.Name] -> Core [TH.Name] -> DsM (Core TH.FunDep)
2067 repFunDep (MkC xs) (MkC ys) = rep2 funDepName [xs, ys]
2068
2069 repProto :: Name -> Core TH.Name -> Core TH.TypeQ -> DsM (Core TH.DecQ)
2070 repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty]
2071
2072 repCtxt :: Core [TH.PredQ] -> DsM (Core TH.CxtQ)
2073 repCtxt (MkC tys) = rep2 cxtName [tys]
2074
2075 repDataCon :: Located Name
2076 -> HsConDeclDetails Name
2077 -> DsM (Core TH.ConQ)
2078 repDataCon con details
2079 = do con' <- lookupLOcc con -- See Note [Binders and occurrences]
2080 repConstr details Nothing [con']
2081
2082 repGadtDataCons :: [Located Name]
2083 -> HsConDeclDetails Name
2084 -> LHsType Name
2085 -> DsM (Core TH.ConQ)
2086 repGadtDataCons cons details res_ty
2087 = do cons' <- mapM lookupLOcc cons -- See Note [Binders and occurrences]
2088 repConstr details (Just res_ty) cons'
2089
2090 -- Invariant:
2091 -- * for plain H98 data constructors second argument is Nothing and third
2092 -- argument is a singleton list
2093 -- * for GADTs data constructors second argument is (Just return_type) and
2094 -- third argument is a non-empty list
2095 repConstr :: HsConDeclDetails Name
2096 -> Maybe (LHsType Name)
2097 -> [Core TH.Name]
2098 -> DsM (Core TH.ConQ)
2099 repConstr (PrefixCon ps) Nothing [con]
2100 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
2101 rep2 normalCName [unC con, unC arg_tys]
2102
2103 repConstr (PrefixCon ps) (Just (L _ res_ty)) cons
2104 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
2105 res_ty' <- repTy res_ty
2106 rep2 gadtCName [ unC (nonEmptyCoreList cons), unC arg_tys, unC res_ty']
2107
2108 repConstr (RecCon (L _ ips)) resTy cons
2109 = do args <- concatMapM rep_ip ips
2110 arg_vtys <- coreList varBangTypeQTyConName args
2111 case resTy of
2112 Nothing -> rep2 recCName [unC (head cons), unC arg_vtys]
2113 Just (L _ res_ty) -> do
2114 res_ty' <- repTy res_ty
2115 rep2 recGadtCName [unC (nonEmptyCoreList cons), unC arg_vtys,
2116 unC res_ty']
2117
2118 where
2119 rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip)
2120
2121 rep_one_ip :: LBangType Name -> LFieldOcc Name -> DsM (Core a)
2122 rep_one_ip t n = do { MkC v <- lookupOcc (selectorFieldOcc $ unLoc n)
2123 ; MkC ty <- repBangTy t
2124 ; rep2 varBangTypeName [v,ty] }
2125
2126 repConstr (InfixCon st1 st2) Nothing [con]
2127 = do arg1 <- repBangTy st1
2128 arg2 <- repBangTy st2
2129 rep2 infixCName [unC arg1, unC con, unC arg2]
2130
2131 repConstr (InfixCon {}) (Just _) _ =
2132 panic "repConstr: infix GADT constructor should be in a PrefixCon"
2133 repConstr _ _ _ =
2134 panic "repConstr: invariant violated"
2135
2136 ------------ Types -------------------
2137
2138 repTForall :: Core [TH.TyVarBndr] -> Core TH.CxtQ -> Core TH.TypeQ
2139 -> DsM (Core TH.TypeQ)
2140 repTForall (MkC tvars) (MkC ctxt) (MkC ty)
2141 = rep2 forallTName [tvars, ctxt, ty]
2142
2143 repTvar :: Core TH.Name -> DsM (Core TH.TypeQ)
2144 repTvar (MkC s) = rep2 varTName [s]
2145
2146 repTapp :: Core TH.TypeQ -> Core TH.TypeQ -> DsM (Core TH.TypeQ)
2147 repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2]
2148
2149 repTapps :: Core TH.TypeQ -> [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2150 repTapps f [] = return f
2151 repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts }
2152
2153 repTSig :: Core TH.TypeQ -> Core TH.Kind -> DsM (Core TH.TypeQ)
2154 repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki]
2155
2156 repTequality :: DsM (Core TH.TypeQ)
2157 repTequality = rep2 equalityTName []
2158
2159 repTPromotedList :: [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2160 repTPromotedList [] = repPromotedNilTyCon
2161 repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon
2162 ; f <- repTapp tcon t
2163 ; t' <- repTPromotedList ts
2164 ; repTapp f t'
2165 }
2166
2167 repTLit :: Core TH.TyLitQ -> DsM (Core TH.TypeQ)
2168 repTLit (MkC lit) = rep2 litTName [lit]
2169
2170 repTWildCard :: DsM (Core TH.TypeQ)
2171 repTWildCard = rep2 wildCardTName []
2172
2173 --------- Type constructors --------------
2174
2175 repNamedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2176 repNamedTyCon (MkC s) = rep2 conTName [s]
2177
2178 repTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2179 -- Note: not Core Int; it's easier to be direct here
2180 repTupleTyCon i = do dflags <- getDynFlags
2181 rep2 tupleTName [mkIntExprInt dflags i]
2182
2183 repUnboxedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2184 -- Note: not Core Int; it's easier to be direct here
2185 repUnboxedTupleTyCon i = do dflags <- getDynFlags
2186 rep2 unboxedTupleTName [mkIntExprInt dflags i]
2187
2188 repArrowTyCon :: DsM (Core TH.TypeQ)
2189 repArrowTyCon = rep2 arrowTName []
2190
2191 repListTyCon :: DsM (Core TH.TypeQ)
2192 repListTyCon = rep2 listTName []
2193
2194 repPromotedDataCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2195 repPromotedDataCon (MkC s) = rep2 promotedTName [s]
2196
2197 repPromotedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2198 repPromotedTupleTyCon i = do dflags <- getDynFlags
2199 rep2 promotedTupleTName [mkIntExprInt dflags i]
2200
2201 repPromotedNilTyCon :: DsM (Core TH.TypeQ)
2202 repPromotedNilTyCon = rep2 promotedNilTName []
2203
2204 repPromotedConsTyCon :: DsM (Core TH.TypeQ)
2205 repPromotedConsTyCon = rep2 promotedConsTName []
2206
2207 ------------ Kinds -------------------
2208
2209 repPlainTV :: Core TH.Name -> DsM (Core TH.TyVarBndr)
2210 repPlainTV (MkC nm) = rep2 plainTVName [nm]
2211
2212 repKindedTV :: Core TH.Name -> Core TH.Kind -> DsM (Core TH.TyVarBndr)
2213 repKindedTV (MkC nm) (MkC ki) = rep2 kindedTVName [nm, ki]
2214
2215 repKVar :: Core TH.Name -> DsM (Core TH.Kind)
2216 repKVar (MkC s) = rep2 varKName [s]
2217
2218 repKCon :: Core TH.Name -> DsM (Core TH.Kind)
2219 repKCon (MkC s) = rep2 conKName [s]
2220
2221 repKTuple :: Int -> DsM (Core TH.Kind)
2222 repKTuple i = do dflags <- getDynFlags
2223 rep2 tupleKName [mkIntExprInt dflags i]
2224
2225 repKArrow :: DsM (Core TH.Kind)
2226 repKArrow = rep2 arrowKName []
2227
2228 repKList :: DsM (Core TH.Kind)
2229 repKList = rep2 listKName []
2230
2231 repKApp :: Core TH.Kind -> Core TH.Kind -> DsM (Core TH.Kind)
2232 repKApp (MkC k1) (MkC k2) = rep2 appKName [k1, k2]
2233
2234 repKApps :: Core TH.Kind -> [Core TH.Kind] -> DsM (Core TH.Kind)
2235 repKApps f [] = return f
2236 repKApps f (k:ks) = do { f' <- repKApp f k; repKApps f' ks }
2237
2238 repKStar :: DsM (Core TH.Kind)
2239 repKStar = rep2 starKName []
2240
2241 repKConstraint :: DsM (Core TH.Kind)
2242 repKConstraint = rep2 constraintKName []
2243
2244 ----------------------------------------------------------
2245 -- Type family result signature
2246
2247 repNoSig :: DsM (Core TH.FamilyResultSig)
2248 repNoSig = rep2 noSigName []
2249
2250 repKindSig :: Core TH.Kind -> DsM (Core TH.FamilyResultSig)
2251 repKindSig (MkC ki) = rep2 kindSigName [ki]
2252
2253 repTyVarSig :: Core TH.TyVarBndr -> DsM (Core TH.FamilyResultSig)
2254 repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr]
2255
2256 ----------------------------------------------------------
2257 -- Literals
2258
2259 repLiteral :: HsLit -> DsM (Core TH.Lit)
2260 repLiteral (HsStringPrim _ bs)
2261 = do dflags <- getDynFlags
2262 word8_ty <- lookupType word8TyConName
2263 let w8s = unpack bs
2264 w8s_expr = map (\w8 -> mkCoreConApps word8DataCon
2265 [mkWordLit dflags (toInteger w8)]) w8s
2266 rep2 stringPrimLName [mkListExpr word8_ty w8s_expr]
2267 repLiteral lit
2268 = do lit' <- case lit of
2269 HsIntPrim _ i -> mk_integer i
2270 HsWordPrim _ w -> mk_integer w
2271 HsInt _ i -> mk_integer i
2272 HsFloatPrim r -> mk_rational r
2273 HsDoublePrim r -> mk_rational r
2274 HsCharPrim _ c -> mk_char c
2275 _ -> return lit
2276 lit_expr <- dsLit lit'
2277 case mb_lit_name of
2278 Just lit_name -> rep2 lit_name [lit_expr]
2279 Nothing -> notHandled "Exotic literal" (ppr lit)
2280 where
2281 mb_lit_name = case lit of
2282 HsInteger _ _ _ -> Just integerLName
2283 HsInt _ _ -> Just integerLName
2284 HsIntPrim _ _ -> Just intPrimLName
2285 HsWordPrim _ _ -> Just wordPrimLName
2286 HsFloatPrim _ -> Just floatPrimLName
2287 HsDoublePrim _ -> Just doublePrimLName
2288 HsChar _ _ -> Just charLName
2289 HsCharPrim _ _ -> Just charPrimLName
2290 HsString _ _ -> Just stringLName
2291 HsRat _ _ -> Just rationalLName
2292 _ -> Nothing
2293
2294 mk_integer :: Integer -> DsM HsLit
2295 mk_integer i = do integer_ty <- lookupType integerTyConName
2296 return $ HsInteger "" i integer_ty
2297 mk_rational :: FractionalLit -> DsM HsLit
2298 mk_rational r = do rat_ty <- lookupType rationalTyConName
2299 return $ HsRat r rat_ty
2300 mk_string :: FastString -> DsM HsLit
2301 mk_string s = return $ HsString "" s
2302
2303 mk_char :: Char -> DsM HsLit
2304 mk_char c = return $ HsChar "" c
2305
2306 repOverloadedLiteral :: HsOverLit Name -> DsM (Core TH.Lit)
2307 repOverloadedLiteral (OverLit { ol_val = val})
2308 = do { lit <- mk_lit val; repLiteral lit }
2309 -- The type Rational will be in the environment, because
2310 -- the smart constructor 'TH.Syntax.rationalL' uses it in its type,
2311 -- and rationalL is sucked in when any TH stuff is used
2312
2313 mk_lit :: OverLitVal -> DsM HsLit
2314 mk_lit (HsIntegral _ i) = mk_integer i
2315 mk_lit (HsFractional f) = mk_rational f
2316 mk_lit (HsIsString _ s) = mk_string s
2317
2318 repNameS :: Core String -> DsM (Core TH.Name)
2319 repNameS (MkC name) = rep2 mkNameSName [name]
2320
2321 --------------- Miscellaneous -------------------
2322
2323 repGensym :: Core String -> DsM (Core (TH.Q TH.Name))
2324 repGensym (MkC lit_str) = rep2 newNameName [lit_str]
2325
2326 repBindQ :: Type -> Type -- a and b
2327 -> Core (TH.Q a) -> Core (a -> TH.Q b) -> DsM (Core (TH.Q b))
2328 repBindQ ty_a ty_b (MkC x) (MkC y)
2329 = rep2 bindQName [Type ty_a, Type ty_b, x, y]
2330
2331 repSequenceQ :: Type -> Core [TH.Q a] -> DsM (Core (TH.Q [a]))
2332 repSequenceQ ty_a (MkC list)
2333 = rep2 sequenceQName [Type ty_a, list]
2334
2335 repUnboundVar :: Core TH.Name -> DsM (Core TH.ExpQ)
2336 repUnboundVar (MkC name) = rep2 unboundVarEName [name]
2337
2338 ------------ Lists -------------------
2339 -- turn a list of patterns into a single pattern matching a list
2340
2341 repList :: Name -> (a -> DsM (Core b))
2342 -> [a] -> DsM (Core [b])
2343 repList tc_name f args
2344 = do { args1 <- mapM f args
2345 ; coreList tc_name args1 }
2346
2347 coreList :: Name -- Of the TyCon of the element type
2348 -> [Core a] -> DsM (Core [a])
2349 coreList tc_name es
2350 = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) }
2351
2352 coreList' :: Type -- The element type
2353 -> [Core a] -> Core [a]
2354 coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es ))
2355
2356 nonEmptyCoreList :: [Core a] -> Core [a]
2357 -- The list must be non-empty so we can get the element type
2358 -- Otherwise use coreList
2359 nonEmptyCoreList [] = panic "coreList: empty argument"
2360 nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs))
2361
2362 coreStringLit :: String -> DsM (Core String)
2363 coreStringLit s = do { z <- mkStringExpr s; return(MkC z) }
2364
2365 ------------------- Maybe ------------------
2366
2367 -- | Construct Core expression for Nothing of a given type name
2368 coreNothing :: Name -- ^ Name of the TyCon of the element type
2369 -> DsM (Core (Maybe a))
2370 coreNothing tc_name =
2371 do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) }
2372
2373 -- | Construct Core expression for Nothing of a given type
2374 coreNothing' :: Type -- ^ The element type
2375 -> Core (Maybe a)
2376 coreNothing' elt_ty = MkC (mkNothingExpr elt_ty)
2377
2378 -- | Store given Core expression in a Just of a given type name
2379 coreJust :: Name -- ^ Name of the TyCon of the element type
2380 -> Core a -> DsM (Core (Maybe a))
2381 coreJust tc_name es
2382 = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) }
2383
2384 -- | Store given Core expression in a Just of a given type
2385 coreJust' :: Type -- ^ The element type
2386 -> Core a -> Core (Maybe a)
2387 coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es))
2388
2389 ------------ Literals & Variables -------------------
2390
2391 coreIntLit :: Int -> DsM (Core Int)
2392 coreIntLit i = do dflags <- getDynFlags
2393 return (MkC (mkIntExprInt dflags i))
2394
2395 coreVar :: Id -> Core TH.Name -- The Id has type Name
2396 coreVar id = MkC (Var id)
2397
2398 ----------------- Failure -----------------------
2399 notHandledL :: SrcSpan -> String -> SDoc -> DsM a
2400 notHandledL loc what doc
2401 | isGoodSrcSpan loc
2402 = putSrcSpanDs loc $ notHandled what doc
2403 | otherwise
2404 = notHandled what doc
2405
2406 notHandled :: String -> SDoc -> DsM a
2407 notHandled what doc = failWithDs msg
2408 where
2409 msg = hang (text what <+> text "not (yet) handled by Template Haskell")
2410 2 doc