Improve typechecking of let-bindings
[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 nm ty)) = (:[]) <$> rep_patsyn_ty_sig loc ty nm
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
1075 rep_splice :: Name -> DsM (Core a)
1076 rep_splice splice_name
1077 = do { mb_val <- dsLookupMetaEnv splice_name
1078 ; case mb_val of
1079 Just (DsSplice e) -> do { e' <- dsExpr e
1080 ; return (MkC e') }
1081 _ -> pprPanic "HsSplice" (ppr splice_name) }
1082 -- Should not happen; statically checked
1083
1084 -----------------------------------------------------------------------------
1085 -- Expressions
1086 -----------------------------------------------------------------------------
1087
1088 repLEs :: [LHsExpr Name] -> DsM (Core [TH.ExpQ])
1089 repLEs es = repList expQTyConName repLE es
1090
1091 -- FIXME: some of these panics should be converted into proper error messages
1092 -- unless we can make sure that constructs, which are plainly not
1093 -- supported in TH already lead to error messages at an earlier stage
1094 repLE :: LHsExpr Name -> DsM (Core TH.ExpQ)
1095 repLE (L loc e) = putSrcSpanDs loc (repE e)
1096
1097 repE :: HsExpr Name -> DsM (Core TH.ExpQ)
1098 repE (HsVar (L _ x)) =
1099 do { mb_val <- dsLookupMetaEnv x
1100 ; case mb_val of
1101 Nothing -> do { str <- globalVar x
1102 ; repVarOrCon x str }
1103 Just (DsBound y) -> repVarOrCon x (coreVar y)
1104 Just (DsSplice e) -> do { e' <- dsExpr e
1105 ; return (MkC e') } }
1106 repE e@(HsIPVar _) = notHandled "Implicit parameters" (ppr e)
1107 repE e@(HsOverLabel _) = notHandled "Overloaded labels" (ppr e)
1108
1109 repE e@(HsRecFld f) = case f of
1110 Unambiguous _ x -> repE (HsVar (noLoc x))
1111 Ambiguous{} -> notHandled "Ambiguous record selectors" (ppr e)
1112
1113 -- Remember, we're desugaring renamer output here, so
1114 -- HsOverlit can definitely occur
1115 repE (HsOverLit l) = do { a <- repOverloadedLiteral l; repLit a }
1116 repE (HsLit l) = do { a <- repLiteral l; repLit a }
1117 repE (HsLam (MG { mg_alts = L _ [m] })) = repLambda m
1118 repE (HsLamCase (MG { mg_alts = L _ ms }))
1119 = do { ms' <- mapM repMatchTup ms
1120 ; core_ms <- coreList matchQTyConName ms'
1121 ; repLamCase core_ms }
1122 repE (HsApp x y) = do {a <- repLE x; b <- repLE y; repApp a b}
1123
1124 repE (OpApp e1 op _ e2) =
1125 do { arg1 <- repLE e1;
1126 arg2 <- repLE e2;
1127 the_op <- repLE op ;
1128 repInfixApp arg1 the_op arg2 }
1129 repE (NegApp x _) = do
1130 a <- repLE x
1131 negateVar <- lookupOcc negateName >>= repVar
1132 negateVar `repApp` a
1133 repE (HsPar x) = repLE x
1134 repE (SectionL x y) = do { a <- repLE x; b <- repLE y; repSectionL a b }
1135 repE (SectionR x y) = do { a <- repLE x; b <- repLE y; repSectionR a b }
1136 repE (HsCase e (MG { mg_alts = L _ ms }))
1137 = do { arg <- repLE e
1138 ; ms2 <- mapM repMatchTup ms
1139 ; core_ms2 <- coreList matchQTyConName ms2
1140 ; repCaseE arg core_ms2 }
1141 repE (HsIf _ x y z) = do
1142 a <- repLE x
1143 b <- repLE y
1144 c <- repLE z
1145 repCond a b c
1146 repE (HsMultiIf _ alts)
1147 = do { (binds, alts') <- liftM unzip $ mapM repLGRHS alts
1148 ; expr' <- repMultiIf (nonEmptyCoreList alts')
1149 ; wrapGenSyms (concat binds) expr' }
1150 repE (HsLet (L _ bs) e) = do { (ss,ds) <- repBinds bs
1151 ; e2 <- addBinds ss (repLE e)
1152 ; z <- repLetE ds e2
1153 ; wrapGenSyms ss z }
1154
1155 -- FIXME: I haven't got the types here right yet
1156 repE e@(HsDo ctxt (L _ sts) _)
1157 | case ctxt of { DoExpr -> True; GhciStmtCtxt -> True; _ -> False }
1158 = do { (ss,zs) <- repLSts sts;
1159 e' <- repDoE (nonEmptyCoreList zs);
1160 wrapGenSyms ss e' }
1161
1162 | ListComp <- ctxt
1163 = do { (ss,zs) <- repLSts sts;
1164 e' <- repComp (nonEmptyCoreList zs);
1165 wrapGenSyms ss e' }
1166
1167 | otherwise
1168 = notHandled "mdo, monad comprehension and [: :]" (ppr e)
1169
1170 repE (ExplicitList _ _ es) = do { xs <- repLEs es; repListExp xs }
1171 repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
1172 repE e@(ExplicitTuple es boxed)
1173 | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
1174 | isBoxed boxed = do { xs <- repLEs [e | L _ (Present e) <- es]; repTup xs }
1175 | otherwise = do { xs <- repLEs [e | L _ (Present e) <- es]
1176 ; repUnboxedTup xs }
1177
1178 repE (RecordCon { rcon_con_name = c, rcon_flds = flds })
1179 = do { x <- lookupLOcc c;
1180 fs <- repFields flds;
1181 repRecCon x fs }
1182 repE (RecordUpd { rupd_expr = e, rupd_flds = flds })
1183 = do { x <- repLE e;
1184 fs <- repUpdFields flds;
1185 repRecUpd x fs }
1186
1187 repE (ExprWithTySig e ty)
1188 = do { e1 <- repLE e
1189 ; t1 <- repHsSigWcType ty
1190 ; repSigExp e1 t1 }
1191
1192 repE (ArithSeq _ _ aseq) =
1193 case aseq of
1194 From e -> do { ds1 <- repLE e; repFrom ds1 }
1195 FromThen e1 e2 -> do
1196 ds1 <- repLE e1
1197 ds2 <- repLE e2
1198 repFromThen ds1 ds2
1199 FromTo e1 e2 -> do
1200 ds1 <- repLE e1
1201 ds2 <- repLE e2
1202 repFromTo ds1 ds2
1203 FromThenTo e1 e2 e3 -> do
1204 ds1 <- repLE e1
1205 ds2 <- repLE e2
1206 ds3 <- repLE e3
1207 repFromThenTo ds1 ds2 ds3
1208
1209 repE (HsSpliceE splice) = repSplice splice
1210 repE (HsStatic _ e) = repLE e >>= rep2 staticEName . (:[]) . unC
1211 repE (HsUnboundVar uv) = do
1212 occ <- occNameLit (unboundVarOcc uv)
1213 sname <- repNameS occ
1214 repUnboundVar sname
1215
1216 repE e@(PArrSeq {}) = notHandled "Parallel arrays" (ppr e)
1217 repE e@(HsCoreAnn {}) = notHandled "Core annotations" (ppr e)
1218 repE e@(HsSCC {}) = notHandled "Cost centres" (ppr e)
1219 repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
1220 repE e@(HsTcBracketOut {}) = notHandled "TH brackets" (ppr e)
1221 repE e = notHandled "Expression form" (ppr e)
1222
1223 -----------------------------------------------------------------------------
1224 -- Building representations of auxillary structures like Match, Clause, Stmt,
1225
1226 repMatchTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.MatchQ)
1227 repMatchTup (L _ (Match _ [p] _ (GRHSs guards (L _ wheres)))) =
1228 do { ss1 <- mkGenSyms (collectPatBinders p)
1229 ; addBinds ss1 $ do {
1230 ; p1 <- repLP p
1231 ; (ss2,ds) <- repBinds wheres
1232 ; addBinds ss2 $ do {
1233 ; gs <- repGuards guards
1234 ; match <- repMatch p1 gs ds
1235 ; wrapGenSyms (ss1++ss2) match }}}
1236 repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
1237
1238 repClauseTup :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ClauseQ)
1239 repClauseTup (L _ (Match _ ps _ (GRHSs guards (L _ wheres)))) =
1240 do { ss1 <- mkGenSyms (collectPatsBinders ps)
1241 ; addBinds ss1 $ do {
1242 ps1 <- repLPs ps
1243 ; (ss2,ds) <- repBinds wheres
1244 ; addBinds ss2 $ do {
1245 gs <- repGuards guards
1246 ; clause <- repClause ps1 gs ds
1247 ; wrapGenSyms (ss1++ss2) clause }}}
1248
1249 repGuards :: [LGRHS Name (LHsExpr Name)] -> DsM (Core TH.BodyQ)
1250 repGuards [L _ (GRHS [] e)]
1251 = do {a <- repLE e; repNormal a }
1252 repGuards other
1253 = do { zs <- mapM repLGRHS other
1254 ; let (xs, ys) = unzip zs
1255 ; gd <- repGuarded (nonEmptyCoreList ys)
1256 ; wrapGenSyms (concat xs) gd }
1257
1258 repLGRHS :: LGRHS Name (LHsExpr Name) -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
1259 repLGRHS (L _ (GRHS [L _ (BodyStmt e1 _ _ _)] e2))
1260 = do { guarded <- repLNormalGE e1 e2
1261 ; return ([], guarded) }
1262 repLGRHS (L _ (GRHS ss rhs))
1263 = do { (gs, ss') <- repLSts ss
1264 ; rhs' <- addBinds gs $ repLE rhs
1265 ; guarded <- repPatGE (nonEmptyCoreList ss') rhs'
1266 ; return (gs, guarded) }
1267
1268 repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
1269 repFields (HsRecFields { rec_flds = flds })
1270 = repList fieldExpQTyConName rep_fld flds
1271 where
1272 rep_fld :: LHsRecField Name (LHsExpr Name) -> DsM (Core (TH.Q TH.FieldExp))
1273 rep_fld (L _ fld) = do { fn <- lookupLOcc (hsRecFieldSel fld)
1274 ; e <- repLE (hsRecFieldArg fld)
1275 ; repFieldExp fn e }
1276
1277 repUpdFields :: [LHsRecUpdField Name] -> DsM (Core [TH.Q TH.FieldExp])
1278 repUpdFields = repList fieldExpQTyConName rep_fld
1279 where
1280 rep_fld :: LHsRecUpdField Name -> DsM (Core (TH.Q TH.FieldExp))
1281 rep_fld (L l fld) = case unLoc (hsRecFieldLbl fld) of
1282 Unambiguous _ sel_name -> do { fn <- lookupLOcc (L l sel_name)
1283 ; e <- repLE (hsRecFieldArg fld)
1284 ; repFieldExp fn e }
1285 _ -> notHandled "Ambiguous record updates" (ppr fld)
1286
1287
1288
1289 -----------------------------------------------------------------------------
1290 -- Representing Stmt's is tricky, especially if bound variables
1291 -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |]
1292 -- First gensym new names for every variable in any of the patterns.
1293 -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
1294 -- if variables didn't shaddow, the static gensym wouldn't be necessary
1295 -- and we could reuse the original names (x and x).
1296 --
1297 -- do { x'1 <- gensym "x"
1298 -- ; x'2 <- gensym "x"
1299 -- ; doE [ BindSt (pvar x'1) [| f 1 |]
1300 -- , BindSt (pvar x'2) [| f x |]
1301 -- , NoBindSt [| g x |]
1302 -- ]
1303 -- }
1304
1305 -- The strategy is to translate a whole list of do-bindings by building a
1306 -- bigger environment, and a bigger set of meta bindings
1307 -- (like: x'1 <- gensym "x" ) and then combining these with the translations
1308 -- of the expressions within the Do
1309
1310 -----------------------------------------------------------------------------
1311 -- The helper function repSts computes the translation of each sub expression
1312 -- and a bunch of prefix bindings denoting the dynamic renaming.
1313
1314 repLSts :: [LStmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1315 repLSts stmts = repSts (map unLoc stmts)
1316
1317 repSts :: [Stmt Name (LHsExpr Name)] -> DsM ([GenSymBind], [Core TH.StmtQ])
1318 repSts (BindStmt p e _ _ _ : ss) =
1319 do { e2 <- repLE e
1320 ; ss1 <- mkGenSyms (collectPatBinders p)
1321 ; addBinds ss1 $ do {
1322 ; p1 <- repLP p;
1323 ; (ss2,zs) <- repSts ss
1324 ; z <- repBindSt p1 e2
1325 ; return (ss1++ss2, z : zs) }}
1326 repSts (LetStmt (L _ bs) : ss) =
1327 do { (ss1,ds) <- repBinds bs
1328 ; z <- repLetSt ds
1329 ; (ss2,zs) <- addBinds ss1 (repSts ss)
1330 ; return (ss1++ss2, z : zs) }
1331 repSts (BodyStmt e _ _ _ : ss) =
1332 do { e2 <- repLE e
1333 ; z <- repNoBindSt e2
1334 ; (ss2,zs) <- repSts ss
1335 ; return (ss2, z : zs) }
1336 repSts (ParStmt stmt_blocks _ _ _ : ss) =
1337 do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks
1338 ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1
1339 ss1 = concat ss_s
1340 ; z <- repParSt stmt_blocks2
1341 ; (ss2, zs) <- addBinds ss1 (repSts ss)
1342 ; return (ss1++ss2, z : zs) }
1343 where
1344 rep_stmt_block :: ParStmtBlock Name Name -> DsM ([GenSymBind], Core [TH.StmtQ])
1345 rep_stmt_block (ParStmtBlock stmts _ _) =
1346 do { (ss1, zs) <- repSts (map unLoc stmts)
1347 ; zs1 <- coreList stmtQTyConName zs
1348 ; return (ss1, zs1) }
1349 repSts [LastStmt e _ _]
1350 = do { e2 <- repLE e
1351 ; z <- repNoBindSt e2
1352 ; return ([], [z]) }
1353 repSts [] = return ([],[])
1354 repSts other = notHandled "Exotic statement" (ppr other)
1355
1356
1357 -----------------------------------------------------------
1358 -- Bindings
1359 -----------------------------------------------------------
1360
1361 repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ])
1362 repBinds EmptyLocalBinds
1363 = do { core_list <- coreList decQTyConName []
1364 ; return ([], core_list) }
1365
1366 repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
1367
1368 repBinds (HsValBinds decs)
1369 = do { let { bndrs = hsSigTvBinders decs ++ collectHsValBinders decs }
1370 -- No need to worrry about detailed scopes within
1371 -- the binding group, because we are talking Names
1372 -- here, so we can safely treat it as a mutually
1373 -- recursive group
1374 -- For hsSigTvBinders see Note [Scoped type variables in bindings]
1375 ; ss <- mkGenSyms bndrs
1376 ; prs <- addBinds ss (rep_val_binds decs)
1377 ; core_list <- coreList decQTyConName
1378 (de_loc (sort_by_loc prs))
1379 ; return (ss, core_list) }
1380
1381 rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1382 -- Assumes: all the binders of the binding are alrady in the meta-env
1383 rep_val_binds (ValBindsOut binds sigs)
1384 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
1385 ; core2 <- rep_sigs' sigs
1386 ; return (core1 ++ core2) }
1387 rep_val_binds (ValBindsIn _ _)
1388 = panic "rep_val_binds: ValBindsIn"
1389
1390 rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
1391 rep_binds binds = do { binds_w_locs <- rep_binds' binds
1392 ; return (de_loc (sort_by_loc binds_w_locs)) }
1393
1394 rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
1395 rep_binds' = mapM rep_bind . bagToList
1396
1397 rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
1398 -- Assumes: all the binders of the binding are alrady in the meta-env
1399
1400 -- Note GHC treats declarations of a variable (not a pattern)
1401 -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match
1402 -- with an empty list of patterns
1403 rep_bind (L loc (FunBind
1404 { fun_id = fn,
1405 fun_matches = MG { mg_alts
1406 = L _ [L _ (Match _ [] _
1407 (GRHSs guards (L _ wheres)))] } }))
1408 = do { (ss,wherecore) <- repBinds wheres
1409 ; guardcore <- addBinds ss (repGuards guards)
1410 ; fn' <- lookupLBinder fn
1411 ; p <- repPvar fn'
1412 ; ans <- repVal p guardcore wherecore
1413 ; ans' <- wrapGenSyms ss ans
1414 ; return (loc, ans') }
1415
1416 rep_bind (L loc (FunBind { fun_id = fn
1417 , fun_matches = MG { mg_alts = L _ ms } }))
1418 = do { ms1 <- mapM repClauseTup ms
1419 ; fn' <- lookupLBinder fn
1420 ; ans <- repFun fn' (nonEmptyCoreList ms1)
1421 ; return (loc, ans) }
1422
1423 rep_bind (L loc (PatBind { pat_lhs = pat
1424 , pat_rhs = GRHSs guards (L _ wheres) }))
1425 = do { patcore <- repLP pat
1426 ; (ss,wherecore) <- repBinds wheres
1427 ; guardcore <- addBinds ss (repGuards guards)
1428 ; ans <- repVal patcore guardcore wherecore
1429 ; ans' <- wrapGenSyms ss ans
1430 ; return (loc, ans') }
1431
1432 rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1433 = do { v' <- lookupBinder v
1434 ; e2 <- repLE e
1435 ; x <- repNormal e2
1436 ; patcore <- repPvar v'
1437 ; empty_decls <- coreList decQTyConName []
1438 ; ans <- repVal patcore x empty_decls
1439 ; return (srcLocSpan (getSrcLoc v), ans) }
1440
1441 rep_bind (L _ (AbsBinds {})) = panic "rep_bind: AbsBinds"
1442 rep_bind (L _ (AbsBindsSig {})) = panic "rep_bind: AbsBindsSig"
1443 rep_bind (L loc (PatSynBind (PSB { psb_id = syn
1444 , psb_fvs = _fvs
1445 , psb_args = args
1446 , psb_def = pat
1447 , psb_dir = dir })))
1448 = do { syn' <- lookupLBinder syn
1449 ; dir' <- repPatSynDir dir
1450 ; ss <- mkGenArgSyms args
1451 ; patSynD' <- addBinds ss (
1452 do { args' <- repPatSynArgs args
1453 ; pat' <- repLP pat
1454 ; repPatSynD syn' args' dir' pat' })
1455 ; patSynD'' <- wrapGenArgSyms args ss patSynD'
1456 ; return (loc, patSynD'') }
1457 where
1458 mkGenArgSyms :: HsPatSynDetails (Located Name) -> DsM [GenSymBind]
1459 -- for Record Pattern Synonyms we want to conflate the selector
1460 -- and the pattern-only names in order to provide a nicer TH
1461 -- API. Whereas inside GHC, record pattern synonym selectors and
1462 -- their pattern-only bound right hand sides have different names,
1463 -- we want to treat them the same in TH. This is the reason why we
1464 -- need an adjusted mkGenArgSyms in the `RecordPatSyn` case below.
1465 mkGenArgSyms (PrefixPatSyn args) = mkGenSyms (map unLoc args)
1466 mkGenArgSyms (InfixPatSyn arg1 arg2) = mkGenSyms [unLoc arg1, unLoc arg2]
1467 mkGenArgSyms (RecordPatSyn fields)
1468 = do { let pats = map (unLoc . recordPatSynPatVar) fields
1469 sels = map (unLoc . recordPatSynSelectorId) fields
1470 ; ss <- mkGenSyms sels
1471 ; return $ replaceNames (zip sels pats) ss }
1472
1473 replaceNames selsPats genSyms
1474 = [ (pat, id) | (sel, id) <- genSyms, (sel', pat) <- selsPats
1475 , sel == sel' ]
1476
1477 wrapGenArgSyms :: HsPatSynDetails (Located Name)
1478 -> [GenSymBind] -> Core TH.DecQ -> DsM (Core TH.DecQ)
1479 wrapGenArgSyms (RecordPatSyn _) _ dec = return dec
1480 wrapGenArgSyms _ ss dec = wrapGenSyms ss dec
1481
1482 repPatSynD :: Core TH.Name
1483 -> Core TH.PatSynArgsQ
1484 -> Core TH.PatSynDirQ
1485 -> Core TH.PatQ
1486 -> DsM (Core TH.DecQ)
1487 repPatSynD (MkC syn) (MkC args) (MkC dir) (MkC pat)
1488 = rep2 patSynDName [syn, args, dir, pat]
1489
1490 repPatSynArgs :: HsPatSynDetails (Located Name) -> DsM (Core TH.PatSynArgsQ)
1491 repPatSynArgs (PrefixPatSyn args)
1492 = do { args' <- repList nameTyConName lookupLOcc args
1493 ; repPrefixPatSynArgs args' }
1494 repPatSynArgs (InfixPatSyn arg1 arg2)
1495 = do { arg1' <- lookupLOcc arg1
1496 ; arg2' <- lookupLOcc arg2
1497 ; repInfixPatSynArgs arg1' arg2' }
1498 repPatSynArgs (RecordPatSyn fields)
1499 = do { sels' <- repList nameTyConName lookupLOcc sels
1500 ; repRecordPatSynArgs sels' }
1501 where sels = map recordPatSynSelectorId fields
1502
1503 repPrefixPatSynArgs :: Core [TH.Name] -> DsM (Core TH.PatSynArgsQ)
1504 repPrefixPatSynArgs (MkC nms) = rep2 prefixPatSynName [nms]
1505
1506 repInfixPatSynArgs :: Core TH.Name -> Core TH.Name -> DsM (Core TH.PatSynArgsQ)
1507 repInfixPatSynArgs (MkC nm1) (MkC nm2) = rep2 infixPatSynName [nm1, nm2]
1508
1509 repRecordPatSynArgs :: Core [TH.Name]
1510 -> DsM (Core TH.PatSynArgsQ)
1511 repRecordPatSynArgs (MkC sels) = rep2 recordPatSynName [sels]
1512
1513 repPatSynDir :: HsPatSynDir Name -> DsM (Core TH.PatSynDirQ)
1514 repPatSynDir Unidirectional = rep2 unidirPatSynName []
1515 repPatSynDir ImplicitBidirectional = rep2 implBidirPatSynName []
1516 repPatSynDir (ExplicitBidirectional (MG { mg_alts = L _ clauses }))
1517 = do { clauses' <- mapM repClauseTup clauses
1518 ; repExplBidirPatSynDir (nonEmptyCoreList clauses') }
1519
1520 repExplBidirPatSynDir :: Core [TH.ClauseQ] -> DsM (Core TH.PatSynDirQ)
1521 repExplBidirPatSynDir (MkC cls) = rep2 explBidirPatSynName [cls]
1522
1523
1524 -----------------------------------------------------------------------------
1525 -- Since everything in a Bind is mutually recursive we need rename all
1526 -- all the variables simultaneously. For example:
1527 -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to
1528 -- do { f'1 <- gensym "f"
1529 -- ; g'2 <- gensym "g"
1530 -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]},
1531 -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]}
1532 -- ]}
1533 -- This requires collecting the bindings (f'1 <- gensym "f"), and the
1534 -- environment ( f |-> f'1 ) from each binding, and then unioning them
1535 -- together. As we do this we collect GenSymBinds's which represent the renamed
1536 -- variables bound by the Bindings. In order not to lose track of these
1537 -- representations we build a shadow datatype MB with the same structure as
1538 -- MonoBinds, but which has slots for the representations
1539
1540
1541 -----------------------------------------------------------------------------
1542 -- GHC allows a more general form of lambda abstraction than specified
1543 -- by Haskell 98. In particular it allows guarded lambda's like :
1544 -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in
1545 -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like
1546 -- (\ p1 .. pn -> exp) by causing an error.
1547
1548 repLambda :: LMatch Name (LHsExpr Name) -> DsM (Core TH.ExpQ)
1549 repLambda (L _ (Match _ ps _ (GRHSs [L _ (GRHS [] e)] (L _ EmptyLocalBinds))))
1550 = do { let bndrs = collectPatsBinders ps ;
1551 ; ss <- mkGenSyms bndrs
1552 ; lam <- addBinds ss (
1553 do { xs <- repLPs ps; body <- repLE e; repLam xs body })
1554 ; wrapGenSyms ss lam }
1555
1556 repLambda (L _ m) = notHandled "Guarded labmdas" (pprMatch m)
1557
1558
1559 -----------------------------------------------------------------------------
1560 -- Patterns
1561 -- repP deals with patterns. It assumes that we have already
1562 -- walked over the pattern(s) once to collect the binders, and
1563 -- have extended the environment. So every pattern-bound
1564 -- variable should already appear in the environment.
1565
1566 -- Process a list of patterns
1567 repLPs :: [LPat Name] -> DsM (Core [TH.PatQ])
1568 repLPs ps = repList patQTyConName repLP ps
1569
1570 repLP :: LPat Name -> DsM (Core TH.PatQ)
1571 repLP (L _ p) = repP p
1572
1573 repP :: Pat Name -> DsM (Core TH.PatQ)
1574 repP (WildPat _) = repPwild
1575 repP (LitPat l) = do { l2 <- repLiteral l; repPlit l2 }
1576 repP (VarPat (L _ x)) = do { x' <- lookupBinder x; repPvar x' }
1577 repP (LazyPat p) = do { p1 <- repLP p; repPtilde p1 }
1578 repP (BangPat p) = do { p1 <- repLP p; repPbang p1 }
1579 repP (AsPat x p) = do { x' <- lookupLBinder x; p1 <- repLP p; repPaspat x' p1 }
1580 repP (ParPat p) = repLP p
1581 repP (ListPat ps _ Nothing) = do { qs <- repLPs ps; repPlist qs }
1582 repP (ListPat ps ty1 (Just (_,e))) = do { p <- repP (ListPat ps ty1 Nothing); e' <- repE (syn_expr e); repPview e' p}
1583 repP (TuplePat ps boxed _)
1584 | isBoxed boxed = do { qs <- repLPs ps; repPtup qs }
1585 | otherwise = do { qs <- repLPs ps; repPunboxedTup qs }
1586 repP (ConPatIn dc details)
1587 = do { con_str <- lookupLOcc dc
1588 ; case details of
1589 PrefixCon ps -> do { qs <- repLPs ps; repPcon con_str qs }
1590 RecCon rec -> do { fps <- repList fieldPatQTyConName rep_fld (rec_flds rec)
1591 ; repPrec con_str fps }
1592 InfixCon p1 p2 -> do { p1' <- repLP p1;
1593 p2' <- repLP p2;
1594 repPinfix p1' con_str p2' }
1595 }
1596 where
1597 rep_fld :: LHsRecField Name (LPat Name) -> DsM (Core (TH.Name,TH.PatQ))
1598 rep_fld (L _ fld) = do { MkC v <- lookupLOcc (hsRecFieldSel fld)
1599 ; MkC p <- repLP (hsRecFieldArg fld)
1600 ; rep2 fieldPatName [v,p] }
1601
1602 repP (NPat (L _ l) Nothing _ _) = do { a <- repOverloadedLiteral l; repPlit a }
1603 repP (ViewPat e p _) = do { e' <- repLE e; p' <- repLP p; repPview e' p' }
1604 repP p@(NPat _ (Just _) _ _) = notHandled "Negative overloaded patterns" (ppr p)
1605 repP p@(SigPatIn {}) = notHandled "Type signatures in patterns" (ppr p)
1606 -- The problem is to do with scoped type variables.
1607 -- To implement them, we have to implement the scoping rules
1608 -- here in DsMeta, and I don't want to do that today!
1609 -- do { p' <- repLP p; t' <- repLTy t; repPsig p' t' }
1610 -- repPsig :: Core TH.PatQ -> Core TH.TypeQ -> DsM (Core TH.PatQ)
1611 -- repPsig (MkC p) (MkC t) = rep2 sigPName [p, t]
1612
1613 repP (SplicePat splice) = repSplice splice
1614
1615 repP other = notHandled "Exotic pattern" (ppr other)
1616
1617 ----------------------------------------------------------
1618 -- Declaration ordering helpers
1619
1620 sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)]
1621 sort_by_loc xs = sortBy comp xs
1622 where comp x y = compare (fst x) (fst y)
1623
1624 de_loc :: [(a, b)] -> [b]
1625 de_loc = map snd
1626
1627 ----------------------------------------------------------
1628 -- The meta-environment
1629
1630 -- A name/identifier association for fresh names of locally bound entities
1631 type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id
1632 -- I.e. (x, x_id) means
1633 -- let x_id = gensym "x" in ...
1634
1635 -- Generate a fresh name for a locally bound entity
1636
1637 mkGenSyms :: [Name] -> DsM [GenSymBind]
1638 -- We can use the existing name. For example:
1639 -- [| \x_77 -> x_77 + x_77 |]
1640 -- desugars to
1641 -- do { x_77 <- genSym "x"; .... }
1642 -- We use the same x_77 in the desugared program, but with the type Bndr
1643 -- instead of Int
1644 --
1645 -- We do make it an Internal name, though (hence localiseName)
1646 --
1647 -- Nevertheless, it's monadic because we have to generate nameTy
1648 mkGenSyms ns = do { var_ty <- lookupType nameTyConName
1649 ; return [(nm, mkLocalId (localiseName nm) var_ty) | nm <- ns] }
1650
1651
1652 addBinds :: [GenSymBind] -> DsM a -> DsM a
1653 -- Add a list of fresh names for locally bound entities to the
1654 -- meta environment (which is part of the state carried around
1655 -- by the desugarer monad)
1656 addBinds bs m = dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs]) m
1657
1658 -- Look up a locally bound name
1659 --
1660 lookupLBinder :: Located Name -> DsM (Core TH.Name)
1661 lookupLBinder (L _ n) = lookupBinder n
1662
1663 lookupBinder :: Name -> DsM (Core TH.Name)
1664 lookupBinder = lookupOcc
1665 -- Binders are brought into scope before the pattern or what-not is
1666 -- desugared. Moreover, in instance declaration the binder of a method
1667 -- will be the selector Id and hence a global; so we need the
1668 -- globalVar case of lookupOcc
1669
1670 -- Look up a name that is either locally bound or a global name
1671 --
1672 -- * If it is a global name, generate the "original name" representation (ie,
1673 -- the <module>:<name> form) for the associated entity
1674 --
1675 lookupLOcc :: Located Name -> DsM (Core TH.Name)
1676 -- Lookup an occurrence; it can't be a splice.
1677 -- Use the in-scope bindings if they exist
1678 lookupLOcc (L _ n) = lookupOcc n
1679
1680 lookupOcc :: Name -> DsM (Core TH.Name)
1681 lookupOcc n
1682 = do { mb_val <- dsLookupMetaEnv n ;
1683 case mb_val of
1684 Nothing -> globalVar n
1685 Just (DsBound x) -> return (coreVar x)
1686 Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n)
1687 }
1688
1689 globalVar :: Name -> DsM (Core TH.Name)
1690 -- Not bound by the meta-env
1691 -- Could be top-level; or could be local
1692 -- f x = $(g [| x |])
1693 -- Here the x will be local
1694 globalVar name
1695 | isExternalName name
1696 = do { MkC mod <- coreStringLit name_mod
1697 ; MkC pkg <- coreStringLit name_pkg
1698 ; MkC occ <- nameLit name
1699 ; rep2 mk_varg [pkg,mod,occ] }
1700 | otherwise
1701 = do { MkC occ <- nameLit name
1702 ; MkC uni <- coreIntLit (getKey (getUnique name))
1703 ; rep2 mkNameLName [occ,uni] }
1704 where
1705 mod = ASSERT( isExternalName name) nameModule name
1706 name_mod = moduleNameString (moduleName mod)
1707 name_pkg = unitIdString (moduleUnitId mod)
1708 name_occ = nameOccName name
1709 mk_varg | OccName.isDataOcc name_occ = mkNameG_dName
1710 | OccName.isVarOcc name_occ = mkNameG_vName
1711 | OccName.isTcOcc name_occ = mkNameG_tcName
1712 | otherwise = pprPanic "DsMeta.globalVar" (ppr name)
1713
1714 lookupType :: Name -- Name of type constructor (e.g. TH.ExpQ)
1715 -> DsM Type -- The type
1716 lookupType tc_name = do { tc <- dsLookupTyCon tc_name ;
1717 return (mkTyConApp tc []) }
1718
1719 wrapGenSyms :: [GenSymBind]
1720 -> Core (TH.Q a) -> DsM (Core (TH.Q a))
1721 -- wrapGenSyms [(nm1,id1), (nm2,id2)] y
1722 -- --> bindQ (gensym nm1) (\ id1 ->
1723 -- bindQ (gensym nm2 (\ id2 ->
1724 -- y))
1725
1726 wrapGenSyms binds body@(MkC b)
1727 = do { var_ty <- lookupType nameTyConName
1728 ; go var_ty binds }
1729 where
1730 [elt_ty] = tcTyConAppArgs (exprType b)
1731 -- b :: Q a, so we can get the type 'a' by looking at the
1732 -- argument type. NB: this relies on Q being a data/newtype,
1733 -- not a type synonym
1734
1735 go _ [] = return body
1736 go var_ty ((name,id) : binds)
1737 = do { MkC body' <- go var_ty binds
1738 ; lit_str <- nameLit name
1739 ; gensym_app <- repGensym lit_str
1740 ; repBindQ var_ty elt_ty
1741 gensym_app (MkC (Lam id body')) }
1742
1743 nameLit :: Name -> DsM (Core String)
1744 nameLit n = coreStringLit (occNameString (nameOccName n))
1745
1746 occNameLit :: OccName -> DsM (Core String)
1747 occNameLit name = coreStringLit (occNameString name)
1748
1749
1750 -- %*********************************************************************
1751 -- %* *
1752 -- Constructing code
1753 -- %* *
1754 -- %*********************************************************************
1755
1756 -----------------------------------------------------------------------------
1757 -- PHANTOM TYPES for consistency. In order to make sure we do this correct
1758 -- we invent a new datatype which uses phantom types.
1759
1760 newtype Core a = MkC CoreExpr
1761 unC :: Core a -> CoreExpr
1762 unC (MkC x) = x
1763
1764 rep2 :: Name -> [ CoreExpr ] -> DsM (Core a)
1765 rep2 n xs = do { id <- dsLookupGlobalId n
1766 ; return (MkC (foldl App (Var id) xs)) }
1767
1768 dataCon' :: Name -> [CoreExpr] -> DsM (Core a)
1769 dataCon' n args = do { id <- dsLookupDataCon n
1770 ; return $ MkC $ mkCoreConApps id args }
1771
1772 dataCon :: Name -> DsM (Core a)
1773 dataCon n = dataCon' n []
1774
1775
1776 -- %*********************************************************************
1777 -- %* *
1778 -- The 'smart constructors'
1779 -- %* *
1780 -- %*********************************************************************
1781
1782 --------------- Patterns -----------------
1783 repPlit :: Core TH.Lit -> DsM (Core TH.PatQ)
1784 repPlit (MkC l) = rep2 litPName [l]
1785
1786 repPvar :: Core TH.Name -> DsM (Core TH.PatQ)
1787 repPvar (MkC s) = rep2 varPName [s]
1788
1789 repPtup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1790 repPtup (MkC ps) = rep2 tupPName [ps]
1791
1792 repPunboxedTup :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1793 repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps]
1794
1795 repPcon :: Core TH.Name -> Core [TH.PatQ] -> DsM (Core TH.PatQ)
1796 repPcon (MkC s) (MkC ps) = rep2 conPName [s, ps]
1797
1798 repPrec :: Core TH.Name -> Core [(TH.Name,TH.PatQ)] -> DsM (Core TH.PatQ)
1799 repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps]
1800
1801 repPinfix :: Core TH.PatQ -> Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1802 repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2]
1803
1804 repPtilde :: Core TH.PatQ -> DsM (Core TH.PatQ)
1805 repPtilde (MkC p) = rep2 tildePName [p]
1806
1807 repPbang :: Core TH.PatQ -> DsM (Core TH.PatQ)
1808 repPbang (MkC p) = rep2 bangPName [p]
1809
1810 repPaspat :: Core TH.Name -> Core TH.PatQ -> DsM (Core TH.PatQ)
1811 repPaspat (MkC s) (MkC p) = rep2 asPName [s, p]
1812
1813 repPwild :: DsM (Core TH.PatQ)
1814 repPwild = rep2 wildPName []
1815
1816 repPlist :: Core [TH.PatQ] -> DsM (Core TH.PatQ)
1817 repPlist (MkC ps) = rep2 listPName [ps]
1818
1819 repPview :: Core TH.ExpQ -> Core TH.PatQ -> DsM (Core TH.PatQ)
1820 repPview (MkC e) (MkC p) = rep2 viewPName [e,p]
1821
1822 --------------- Expressions -----------------
1823 repVarOrCon :: Name -> Core TH.Name -> DsM (Core TH.ExpQ)
1824 repVarOrCon vc str | isDataOcc (nameOccName vc) = repCon str
1825 | otherwise = repVar str
1826
1827 repVar :: Core TH.Name -> DsM (Core TH.ExpQ)
1828 repVar (MkC s) = rep2 varEName [s]
1829
1830 repCon :: Core TH.Name -> DsM (Core TH.ExpQ)
1831 repCon (MkC s) = rep2 conEName [s]
1832
1833 repLit :: Core TH.Lit -> DsM (Core TH.ExpQ)
1834 repLit (MkC c) = rep2 litEName [c]
1835
1836 repApp :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1837 repApp (MkC x) (MkC y) = rep2 appEName [x,y]
1838
1839 repLam :: Core [TH.PatQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1840 repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e]
1841
1842 repLamCase :: Core [TH.MatchQ] -> DsM (Core TH.ExpQ)
1843 repLamCase (MkC ms) = rep2 lamCaseEName [ms]
1844
1845 repTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1846 repTup (MkC es) = rep2 tupEName [es]
1847
1848 repUnboxedTup :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1849 repUnboxedTup (MkC es) = rep2 unboxedTupEName [es]
1850
1851 repCond :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1852 repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z]
1853
1854 repMultiIf :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.ExpQ)
1855 repMultiIf (MkC alts) = rep2 multiIfEName [alts]
1856
1857 repLetE :: Core [TH.DecQ] -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1858 repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e]
1859
1860 repCaseE :: Core TH.ExpQ -> Core [TH.MatchQ] -> DsM( Core TH.ExpQ)
1861 repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms]
1862
1863 repDoE :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1864 repDoE (MkC ss) = rep2 doEName [ss]
1865
1866 repComp :: Core [TH.StmtQ] -> DsM (Core TH.ExpQ)
1867 repComp (MkC ss) = rep2 compEName [ss]
1868
1869 repListExp :: Core [TH.ExpQ] -> DsM (Core TH.ExpQ)
1870 repListExp (MkC es) = rep2 listEName [es]
1871
1872 repSigExp :: Core TH.ExpQ -> Core TH.TypeQ -> DsM (Core TH.ExpQ)
1873 repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t]
1874
1875 repRecCon :: Core TH.Name -> Core [TH.Q TH.FieldExp]-> DsM (Core TH.ExpQ)
1876 repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs]
1877
1878 repRecUpd :: Core TH.ExpQ -> Core [TH.Q TH.FieldExp] -> DsM (Core TH.ExpQ)
1879 repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs]
1880
1881 repFieldExp :: Core TH.Name -> Core TH.ExpQ -> DsM (Core (TH.Q TH.FieldExp))
1882 repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x]
1883
1884 repInfixApp :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1885 repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z]
1886
1887 repSectionL :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1888 repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y]
1889
1890 repSectionR :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1891 repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y]
1892
1893 ------------ Right hand sides (guarded expressions) ----
1894 repGuarded :: Core [TH.Q (TH.Guard, TH.Exp)] -> DsM (Core TH.BodyQ)
1895 repGuarded (MkC pairs) = rep2 guardedBName [pairs]
1896
1897 repNormal :: Core TH.ExpQ -> DsM (Core TH.BodyQ)
1898 repNormal (MkC e) = rep2 normalBName [e]
1899
1900 ------------ Guards ----
1901 repLNormalGE :: LHsExpr Name -> LHsExpr Name -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1902 repLNormalGE g e = do g' <- repLE g
1903 e' <- repLE e
1904 repNormalGE g' e'
1905
1906 repNormalGE :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1907 repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e]
1908
1909 repPatGE :: Core [TH.StmtQ] -> Core TH.ExpQ -> DsM (Core (TH.Q (TH.Guard, TH.Exp)))
1910 repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e]
1911
1912 ------------- Stmts -------------------
1913 repBindSt :: Core TH.PatQ -> Core TH.ExpQ -> DsM (Core TH.StmtQ)
1914 repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e]
1915
1916 repLetSt :: Core [TH.DecQ] -> DsM (Core TH.StmtQ)
1917 repLetSt (MkC ds) = rep2 letSName [ds]
1918
1919 repNoBindSt :: Core TH.ExpQ -> DsM (Core TH.StmtQ)
1920 repNoBindSt (MkC e) = rep2 noBindSName [e]
1921
1922 repParSt :: Core [[TH.StmtQ]] -> DsM (Core TH.StmtQ)
1923 repParSt (MkC sss) = rep2 parSName [sss]
1924
1925 -------------- Range (Arithmetic sequences) -----------
1926 repFrom :: Core TH.ExpQ -> DsM (Core TH.ExpQ)
1927 repFrom (MkC x) = rep2 fromEName [x]
1928
1929 repFromThen :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1930 repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y]
1931
1932 repFromTo :: Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1933 repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y]
1934
1935 repFromThenTo :: Core TH.ExpQ -> Core TH.ExpQ -> Core TH.ExpQ -> DsM (Core TH.ExpQ)
1936 repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z]
1937
1938 ------------ Match and Clause Tuples -----------
1939 repMatch :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.MatchQ)
1940 repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds]
1941
1942 repClause :: Core [TH.PatQ] -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.ClauseQ)
1943 repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds]
1944
1945 -------------- Dec -----------------------------
1946 repVal :: Core TH.PatQ -> Core TH.BodyQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1947 repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds]
1948
1949 repFun :: Core TH.Name -> Core [TH.ClauseQ] -> DsM (Core TH.DecQ)
1950 repFun (MkC nm) (MkC b) = rep2 funDName [nm, b]
1951
1952 repData :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1953 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1954 -> Core [TH.ConQ] -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1955 repData (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC cons) (MkC derivs)
1956 = rep2 dataDName [cxt, nm, tvs, ksig, cons, derivs]
1957 repData (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC cons)
1958 (MkC derivs)
1959 = rep2 dataInstDName [cxt, nm, tys, ksig, cons, derivs]
1960
1961 repNewtype :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1962 -> Maybe (Core [TH.TypeQ]) -> Core (Maybe TH.Kind)
1963 -> Core TH.ConQ -> Core TH.CxtQ -> DsM (Core TH.DecQ)
1964 repNewtype (MkC cxt) (MkC nm) (MkC tvs) Nothing (MkC ksig) (MkC con)
1965 (MkC derivs)
1966 = rep2 newtypeDName [cxt, nm, tvs, ksig, con, derivs]
1967 repNewtype (MkC cxt) (MkC nm) (MkC _) (Just (MkC tys)) (MkC ksig) (MkC con)
1968 (MkC derivs)
1969 = rep2 newtypeInstDName [cxt, nm, tys, ksig, con, derivs]
1970
1971 repTySyn :: Core TH.Name -> Core [TH.TyVarBndr]
1972 -> Core TH.TypeQ -> DsM (Core TH.DecQ)
1973 repTySyn (MkC nm) (MkC tvs) (MkC rhs)
1974 = rep2 tySynDName [nm, tvs, rhs]
1975
1976 repInst :: Core (Maybe TH.Overlap) ->
1977 Core TH.CxtQ -> Core TH.TypeQ -> Core [TH.DecQ] -> DsM (Core TH.DecQ)
1978 repInst (MkC o) (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceWithOverlapDName
1979 [o, cxt, ty, ds]
1980
1981 repOverlap :: Maybe OverlapMode -> DsM (Core (Maybe TH.Overlap))
1982 repOverlap mb =
1983 case mb of
1984 Nothing -> nothing
1985 Just o ->
1986 case o of
1987 NoOverlap _ -> nothing
1988 Overlappable _ -> just =<< dataCon overlappableDataConName
1989 Overlapping _ -> just =<< dataCon overlappingDataConName
1990 Overlaps _ -> just =<< dataCon overlapsDataConName
1991 Incoherent _ -> just =<< dataCon incoherentDataConName
1992 where
1993 nothing = coreNothing overlapTyConName
1994 just = coreJust overlapTyConName
1995
1996
1997 repClass :: Core TH.CxtQ -> Core TH.Name -> Core [TH.TyVarBndr]
1998 -> Core [TH.FunDep] -> Core [TH.DecQ]
1999 -> DsM (Core TH.DecQ)
2000 repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds)
2001 = rep2 classDName [cxt, cls, tvs, fds, ds]
2002
2003 repDeriv :: Core TH.CxtQ -> Core TH.TypeQ -> DsM (Core TH.DecQ)
2004 repDeriv (MkC cxt) (MkC ty) = rep2 standaloneDerivDName [cxt, ty]
2005
2006 repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch
2007 -> Core TH.Phases -> DsM (Core TH.DecQ)
2008 repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases)
2009 = rep2 pragInlDName [nm, inline, rm, phases]
2010
2011 repPragSpec :: Core TH.Name -> Core TH.TypeQ -> Core TH.Phases
2012 -> DsM (Core TH.DecQ)
2013 repPragSpec (MkC nm) (MkC ty) (MkC phases)
2014 = rep2 pragSpecDName [nm, ty, phases]
2015
2016 repPragSpecInl :: Core TH.Name -> Core TH.TypeQ -> Core TH.Inline
2017 -> Core TH.Phases -> DsM (Core TH.DecQ)
2018 repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases)
2019 = rep2 pragSpecInlDName [nm, ty, inline, phases]
2020
2021 repPragSpecInst :: Core TH.TypeQ -> DsM (Core TH.DecQ)
2022 repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty]
2023
2024 repPragRule :: Core String -> Core [TH.RuleBndrQ] -> Core TH.ExpQ
2025 -> Core TH.ExpQ -> Core TH.Phases -> DsM (Core TH.DecQ)
2026 repPragRule (MkC nm) (MkC bndrs) (MkC lhs) (MkC rhs) (MkC phases)
2027 = rep2 pragRuleDName [nm, bndrs, lhs, rhs, phases]
2028
2029 repPragAnn :: Core TH.AnnTarget -> Core TH.ExpQ -> DsM (Core TH.DecQ)
2030 repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e]
2031
2032 repTySynInst :: Core TH.Name -> Core TH.TySynEqnQ -> DsM (Core TH.DecQ)
2033 repTySynInst (MkC nm) (MkC eqn)
2034 = rep2 tySynInstDName [nm, eqn]
2035
2036 repDataFamilyD :: Core TH.Name -> Core [TH.TyVarBndr]
2037 -> Core (Maybe TH.Kind) -> DsM (Core TH.DecQ)
2038 repDataFamilyD (MkC nm) (MkC tvs) (MkC kind)
2039 = rep2 dataFamilyDName [nm, tvs, kind]
2040
2041 repOpenFamilyD :: Core TH.Name
2042 -> Core [TH.TyVarBndr]
2043 -> Core TH.FamilyResultSig
2044 -> Core (Maybe TH.InjectivityAnn)
2045 -> DsM (Core TH.DecQ)
2046 repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj)
2047 = rep2 openTypeFamilyDName [nm, tvs, result, inj]
2048
2049 repClosedFamilyD :: Core TH.Name
2050 -> Core [TH.TyVarBndr]
2051 -> Core TH.FamilyResultSig
2052 -> Core (Maybe TH.InjectivityAnn)
2053 -> Core [TH.TySynEqnQ]
2054 -> DsM (Core TH.DecQ)
2055 repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns)
2056 = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns]
2057
2058 repTySynEqn :: Core [TH.TypeQ] -> Core TH.TypeQ -> DsM (Core TH.TySynEqnQ)
2059 repTySynEqn (MkC lhs) (MkC rhs)
2060 = rep2 tySynEqnName [lhs, rhs]
2061
2062 repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> DsM (Core TH.DecQ)
2063 repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles]
2064
2065 repFunDep :: Core [TH.Name] -> Core [TH.Name] -> DsM (Core TH.FunDep)
2066 repFunDep (MkC xs) (MkC ys) = rep2 funDepName [xs, ys]
2067
2068 repProto :: Name -> Core TH.Name -> Core TH.TypeQ -> DsM (Core TH.DecQ)
2069 repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty]
2070
2071 repCtxt :: Core [TH.PredQ] -> DsM (Core TH.CxtQ)
2072 repCtxt (MkC tys) = rep2 cxtName [tys]
2073
2074 repDataCon :: Located Name
2075 -> HsConDeclDetails Name
2076 -> DsM (Core TH.ConQ)
2077 repDataCon con details
2078 = do con' <- lookupLOcc con -- See Note [Binders and occurrences]
2079 repConstr details Nothing [con']
2080
2081 repGadtDataCons :: [Located Name]
2082 -> HsConDeclDetails Name
2083 -> LHsType Name
2084 -> DsM (Core TH.ConQ)
2085 repGadtDataCons cons details res_ty
2086 = do cons' <- mapM lookupLOcc cons -- See Note [Binders and occurrences]
2087 repConstr details (Just res_ty) cons'
2088
2089 -- Invariant:
2090 -- * for plain H98 data constructors second argument is Nothing and third
2091 -- argument is a singleton list
2092 -- * for GADTs data constructors second argument is (Just return_type) and
2093 -- third argument is a non-empty list
2094 repConstr :: HsConDeclDetails Name
2095 -> Maybe (LHsType Name)
2096 -> [Core TH.Name]
2097 -> DsM (Core TH.ConQ)
2098 repConstr (PrefixCon ps) Nothing [con]
2099 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
2100 rep2 normalCName [unC con, unC arg_tys]
2101
2102 repConstr (PrefixCon ps) (Just (L _ res_ty)) cons
2103 = do arg_tys <- repList bangTypeQTyConName repBangTy ps
2104 res_ty' <- repTy res_ty
2105 rep2 gadtCName [ unC (nonEmptyCoreList cons), unC arg_tys, unC res_ty']
2106
2107 repConstr (RecCon (L _ ips)) resTy cons
2108 = do args <- concatMapM rep_ip ips
2109 arg_vtys <- coreList varBangTypeQTyConName args
2110 case resTy of
2111 Nothing -> rep2 recCName [unC (head cons), unC arg_vtys]
2112 Just (L _ res_ty) -> do
2113 res_ty' <- repTy res_ty
2114 rep2 recGadtCName [unC (nonEmptyCoreList cons), unC arg_vtys,
2115 unC res_ty']
2116
2117 where
2118 rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip)
2119
2120 rep_one_ip :: LBangType Name -> LFieldOcc Name -> DsM (Core a)
2121 rep_one_ip t n = do { MkC v <- lookupOcc (selectorFieldOcc $ unLoc n)
2122 ; MkC ty <- repBangTy t
2123 ; rep2 varBangTypeName [v,ty] }
2124
2125 repConstr (InfixCon st1 st2) Nothing [con]
2126 = do arg1 <- repBangTy st1
2127 arg2 <- repBangTy st2
2128 rep2 infixCName [unC arg1, unC con, unC arg2]
2129
2130 repConstr (InfixCon {}) (Just _) _ =
2131 panic "repConstr: infix GADT constructor should be in a PrefixCon"
2132 repConstr _ _ _ =
2133 panic "repConstr: invariant violated"
2134
2135 ------------ Types -------------------
2136
2137 repTForall :: Core [TH.TyVarBndr] -> Core TH.CxtQ -> Core TH.TypeQ
2138 -> DsM (Core TH.TypeQ)
2139 repTForall (MkC tvars) (MkC ctxt) (MkC ty)
2140 = rep2 forallTName [tvars, ctxt, ty]
2141
2142 repTvar :: Core TH.Name -> DsM (Core TH.TypeQ)
2143 repTvar (MkC s) = rep2 varTName [s]
2144
2145 repTapp :: Core TH.TypeQ -> Core TH.TypeQ -> DsM (Core TH.TypeQ)
2146 repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2]
2147
2148 repTapps :: Core TH.TypeQ -> [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2149 repTapps f [] = return f
2150 repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts }
2151
2152 repTSig :: Core TH.TypeQ -> Core TH.Kind -> DsM (Core TH.TypeQ)
2153 repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki]
2154
2155 repTequality :: DsM (Core TH.TypeQ)
2156 repTequality = rep2 equalityTName []
2157
2158 repTPromotedList :: [Core TH.TypeQ] -> DsM (Core TH.TypeQ)
2159 repTPromotedList [] = repPromotedNilTyCon
2160 repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon
2161 ; f <- repTapp tcon t
2162 ; t' <- repTPromotedList ts
2163 ; repTapp f t'
2164 }
2165
2166 repTLit :: Core TH.TyLitQ -> DsM (Core TH.TypeQ)
2167 repTLit (MkC lit) = rep2 litTName [lit]
2168
2169 repTWildCard :: DsM (Core TH.TypeQ)
2170 repTWildCard = rep2 wildCardTName []
2171
2172 --------- Type constructors --------------
2173
2174 repNamedTyCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2175 repNamedTyCon (MkC s) = rep2 conTName [s]
2176
2177 repTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2178 -- Note: not Core Int; it's easier to be direct here
2179 repTupleTyCon i = do dflags <- getDynFlags
2180 rep2 tupleTName [mkIntExprInt dflags i]
2181
2182 repUnboxedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2183 -- Note: not Core Int; it's easier to be direct here
2184 repUnboxedTupleTyCon i = do dflags <- getDynFlags
2185 rep2 unboxedTupleTName [mkIntExprInt dflags i]
2186
2187 repArrowTyCon :: DsM (Core TH.TypeQ)
2188 repArrowTyCon = rep2 arrowTName []
2189
2190 repListTyCon :: DsM (Core TH.TypeQ)
2191 repListTyCon = rep2 listTName []
2192
2193 repPromotedDataCon :: Core TH.Name -> DsM (Core TH.TypeQ)
2194 repPromotedDataCon (MkC s) = rep2 promotedTName [s]
2195
2196 repPromotedTupleTyCon :: Int -> DsM (Core TH.TypeQ)
2197 repPromotedTupleTyCon i = do dflags <- getDynFlags
2198 rep2 promotedTupleTName [mkIntExprInt dflags i]
2199
2200 repPromotedNilTyCon :: DsM (Core TH.TypeQ)
2201 repPromotedNilTyCon = rep2 promotedNilTName []
2202
2203 repPromotedConsTyCon :: DsM (Core TH.TypeQ)
2204 repPromotedConsTyCon = rep2 promotedConsTName []
2205
2206 ------------ Kinds -------------------
2207
2208 repPlainTV :: Core TH.Name -> DsM (Core TH.TyVarBndr)
2209 repPlainTV (MkC nm) = rep2 plainTVName [nm]
2210
2211 repKindedTV :: Core TH.Name -> Core TH.Kind -> DsM (Core TH.TyVarBndr)
2212 repKindedTV (MkC nm) (MkC ki) = rep2 kindedTVName [nm, ki]
2213
2214 repKVar :: Core TH.Name -> DsM (Core TH.Kind)
2215 repKVar (MkC s) = rep2 varKName [s]
2216
2217 repKCon :: Core TH.Name -> DsM (Core TH.Kind)
2218 repKCon (MkC s) = rep2 conKName [s]
2219
2220 repKTuple :: Int -> DsM (Core TH.Kind)
2221 repKTuple i = do dflags <- getDynFlags
2222 rep2 tupleKName [mkIntExprInt dflags i]
2223
2224 repKArrow :: DsM (Core TH.Kind)
2225 repKArrow = rep2 arrowKName []
2226
2227 repKList :: DsM (Core TH.Kind)
2228 repKList = rep2 listKName []
2229
2230 repKApp :: Core TH.Kind -> Core TH.Kind -> DsM (Core TH.Kind)
2231 repKApp (MkC k1) (MkC k2) = rep2 appKName [k1, k2]
2232
2233 repKApps :: Core TH.Kind -> [Core TH.Kind] -> DsM (Core TH.Kind)
2234 repKApps f [] = return f
2235 repKApps f (k:ks) = do { f' <- repKApp f k; repKApps f' ks }
2236
2237 repKStar :: DsM (Core TH.Kind)
2238 repKStar = rep2 starKName []
2239
2240 repKConstraint :: DsM (Core TH.Kind)
2241 repKConstraint = rep2 constraintKName []
2242
2243 ----------------------------------------------------------
2244 -- Type family result signature
2245
2246 repNoSig :: DsM (Core TH.FamilyResultSig)
2247 repNoSig = rep2 noSigName []
2248
2249 repKindSig :: Core TH.Kind -> DsM (Core TH.FamilyResultSig)
2250 repKindSig (MkC ki) = rep2 kindSigName [ki]
2251
2252 repTyVarSig :: Core TH.TyVarBndr -> DsM (Core TH.FamilyResultSig)
2253 repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr]
2254
2255 ----------------------------------------------------------
2256 -- Literals
2257
2258 repLiteral :: HsLit -> DsM (Core TH.Lit)
2259 repLiteral (HsStringPrim _ bs)
2260 = do dflags <- getDynFlags
2261 word8_ty <- lookupType word8TyConName
2262 let w8s = unpack bs
2263 w8s_expr = map (\w8 -> mkCoreConApps word8DataCon
2264 [mkWordLit dflags (toInteger w8)]) w8s
2265 rep2 stringPrimLName [mkListExpr word8_ty w8s_expr]
2266 repLiteral lit
2267 = do lit' <- case lit of
2268 HsIntPrim _ i -> mk_integer i
2269 HsWordPrim _ w -> mk_integer w
2270 HsInt _ i -> mk_integer i
2271 HsFloatPrim r -> mk_rational r
2272 HsDoublePrim r -> mk_rational r
2273 HsCharPrim _ c -> mk_char c
2274 _ -> return lit
2275 lit_expr <- dsLit lit'
2276 case mb_lit_name of
2277 Just lit_name -> rep2 lit_name [lit_expr]
2278 Nothing -> notHandled "Exotic literal" (ppr lit)
2279 where
2280 mb_lit_name = case lit of
2281 HsInteger _ _ _ -> Just integerLName
2282 HsInt _ _ -> Just integerLName
2283 HsIntPrim _ _ -> Just intPrimLName
2284 HsWordPrim _ _ -> Just wordPrimLName
2285 HsFloatPrim _ -> Just floatPrimLName
2286 HsDoublePrim _ -> Just doublePrimLName
2287 HsChar _ _ -> Just charLName
2288 HsCharPrim _ _ -> Just charPrimLName
2289 HsString _ _ -> Just stringLName
2290 HsRat _ _ -> Just rationalLName
2291 _ -> Nothing
2292
2293 mk_integer :: Integer -> DsM HsLit
2294 mk_integer i = do integer_ty <- lookupType integerTyConName
2295 return $ HsInteger "" i integer_ty
2296 mk_rational :: FractionalLit -> DsM HsLit
2297 mk_rational r = do rat_ty <- lookupType rationalTyConName
2298 return $ HsRat r rat_ty
2299 mk_string :: FastString -> DsM HsLit
2300 mk_string s = return $ HsString "" s
2301
2302 mk_char :: Char -> DsM HsLit
2303 mk_char c = return $ HsChar "" c
2304
2305 repOverloadedLiteral :: HsOverLit Name -> DsM (Core TH.Lit)
2306 repOverloadedLiteral (OverLit { ol_val = val})
2307 = do { lit <- mk_lit val; repLiteral lit }
2308 -- The type Rational will be in the environment, because
2309 -- the smart constructor 'TH.Syntax.rationalL' uses it in its type,
2310 -- and rationalL is sucked in when any TH stuff is used
2311
2312 mk_lit :: OverLitVal -> DsM HsLit
2313 mk_lit (HsIntegral _ i) = mk_integer i
2314 mk_lit (HsFractional f) = mk_rational f
2315 mk_lit (HsIsString _ s) = mk_string s
2316
2317 repNameS :: Core String -> DsM (Core TH.Name)
2318 repNameS (MkC name) = rep2 mkNameSName [name]
2319
2320 --------------- Miscellaneous -------------------
2321
2322 repGensym :: Core String -> DsM (Core (TH.Q TH.Name))
2323 repGensym (MkC lit_str) = rep2 newNameName [lit_str]
2324
2325 repBindQ :: Type -> Type -- a and b
2326 -> Core (TH.Q a) -> Core (a -> TH.Q b) -> DsM (Core (TH.Q b))
2327 repBindQ ty_a ty_b (MkC x) (MkC y)
2328 = rep2 bindQName [Type ty_a, Type ty_b, x, y]
2329
2330 repSequenceQ :: Type -> Core [TH.Q a] -> DsM (Core (TH.Q [a]))
2331 repSequenceQ ty_a (MkC list)
2332 = rep2 sequenceQName [Type ty_a, list]
2333
2334 repUnboundVar :: Core TH.Name -> DsM (Core TH.ExpQ)
2335 repUnboundVar (MkC name) = rep2 unboundVarEName [name]
2336
2337 ------------ Lists -------------------
2338 -- turn a list of patterns into a single pattern matching a list
2339
2340 repList :: Name -> (a -> DsM (Core b))
2341 -> [a] -> DsM (Core [b])
2342 repList tc_name f args
2343 = do { args1 <- mapM f args
2344 ; coreList tc_name args1 }
2345
2346 coreList :: Name -- Of the TyCon of the element type
2347 -> [Core a] -> DsM (Core [a])
2348 coreList tc_name es
2349 = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) }
2350
2351 coreList' :: Type -- The element type
2352 -> [Core a] -> Core [a]
2353 coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es ))
2354
2355 nonEmptyCoreList :: [Core a] -> Core [a]
2356 -- The list must be non-empty so we can get the element type
2357 -- Otherwise use coreList
2358 nonEmptyCoreList [] = panic "coreList: empty argument"
2359 nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs))
2360
2361 coreStringLit :: String -> DsM (Core String)
2362 coreStringLit s = do { z <- mkStringExpr s; return(MkC z) }
2363
2364 ------------------- Maybe ------------------
2365
2366 -- | Construct Core expression for Nothing of a given type name
2367 coreNothing :: Name -- ^ Name of the TyCon of the element type
2368 -> DsM (Core (Maybe a))
2369 coreNothing tc_name =
2370 do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) }
2371
2372 -- | Construct Core expression for Nothing of a given type
2373 coreNothing' :: Type -- ^ The element type
2374 -> Core (Maybe a)
2375 coreNothing' elt_ty = MkC (mkNothingExpr elt_ty)
2376
2377 -- | Store given Core expression in a Just of a given type name
2378 coreJust :: Name -- ^ Name of the TyCon of the element type
2379 -> Core a -> DsM (Core (Maybe a))
2380 coreJust tc_name es
2381 = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) }
2382
2383 -- | Store given Core expression in a Just of a given type
2384 coreJust' :: Type -- ^ The element type
2385 -> Core a -> Core (Maybe a)
2386 coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es))
2387
2388 ------------ Literals & Variables -------------------
2389
2390 coreIntLit :: Int -> DsM (Core Int)
2391 coreIntLit i = do dflags <- getDynFlags
2392 return (MkC (mkIntExprInt dflags i))
2393
2394 coreVar :: Id -> Core TH.Name -- The Id has type Name
2395 coreVar id = MkC (Var id)
2396
2397 ----------------- Failure -----------------------
2398 notHandledL :: SrcSpan -> String -> SDoc -> DsM a
2399 notHandledL loc what doc
2400 | isGoodSrcSpan loc
2401 = putSrcSpanDs loc $ notHandled what doc
2402 | otherwise
2403 = notHandled what doc
2404
2405 notHandled :: String -> SDoc -> DsM a
2406 notHandled what doc = failWithDs msg
2407 where
2408 msg = hang (text what <+> text "not (yet) handled by Template Haskell")
2409 2 doc