DsMeta.hs 88.7 KB
Newer Older
1
-----------------------------------------------------------------------------
Simon Marlow's avatar
Simon Marlow committed
2 3 4
--
-- (c) The University of Glasgow 2006
--
5 6 7 8
-- The purpose of this module is to transform an HsExpr into a CoreExpr which
-- when evaluated, returns a (Meta.Q Meta.Exp) computation analogous to the
-- input HsExpr. We do this in the DsM monad, which supplies access to
-- CoreExpr's of the "smart constructors" of the Meta.Exp datatype.
9 10 11 12 13
--
-- It also defines a bunch of knownKeyNames, in the same way as is done
-- in prelude/PrelNames.  It's much more convenient to do it here, becuase
-- otherwise we have to recompile PrelNames whenever we add a Name, which is
-- a Royal Pain (triggers other recompilation).
14 15
-----------------------------------------------------------------------------

Ian Lynagh's avatar
Ian Lynagh committed
16 17 18 19 20 21 22
{-# OPTIONS -fno-warn-tabs #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and
-- detab the module (please do the detabbing in a separate patch). See
--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
-- for details

23 24
module DsMeta( dsBracket, 
	       templateHaskellNames, qTyConName, nameTyConName,
25 26
	       liftName, liftStringName, expQTyConName, patQTyConName, 
               decQTyConName, decsQTyConName, typeQTyConName,
27
	       decTyConName, typeTyConName, mkNameG_dName, mkNameG_vName, mkNameG_tcName,
28
	       quoteExpName, quotePatName, quoteDecName, quoteTypeName
29
	        ) where
30

31 32
#include "HsVersions.h"

33 34
import {-# SOURCE #-}	DsExpr ( dsExpr )

Simon Marlow's avatar
Simon Marlow committed
35
import MatchLit
36 37
import DsMonad

38
import qualified Language.Haskell.TH as TH
39

40
import HsSyn
Simon Marlow's avatar
Simon Marlow committed
41 42 43 44 45 46
import Class
import PrelNames
-- To avoid clashes with DsMeta.varName we must make a local alias for
-- OccName.varName we do this by removing varName from the import of
-- OccName above, making a qualified instance of OccName and using
-- OccNameAlias.varName where varName ws previously used in this file.
47
import qualified OccName( isDataOcc, isVarOcc, isTcOcc, varName, tcName ) 
48

Simon Marlow's avatar
Simon Marlow committed
49 50
import Module
import Id
51
import Name hiding( isVarOcc, isTcOcc, varName, tcName ) 
52
import NameEnv
Simon Marlow's avatar
Simon Marlow committed
53 54 55
import TcType
import TyCon
import TysWiredIn
dreixel's avatar
dreixel committed
56
import TysPrim ( liftedTypeKindTyConName )
57
import CoreSyn
58
import MkCore
Simon Marlow's avatar
Simon Marlow committed
59 60 61 62
import CoreUtils
import SrcLoc
import Unique
import BasicTypes
63
import Outputable
Simon Marlow's avatar
Simon Marlow committed
64 65 66
import Bag
import FastString
import ForeignCall
67
import MonadUtils
68
import Util( equalLength )
69

Simon Marlow's avatar
Simon Marlow committed
70 71 72
import Data.Maybe
import Control.Monad
import Data.List
Ian Lynagh's avatar
Ian Lynagh committed
73

74 75
-----------------------------------------------------------------------------
dsBracket :: HsBracket Name -> [PendingSplice] -> DsM CoreExpr
76
-- Returns a CoreExpr of type TH.ExpQ
77 78 79
-- The quoted thing is parameterised over Name, even though it has
-- been type checked.  We don't want all those type decorations!

80 81
dsBracket brack splices
  = dsExtendMetaEnv new_bit (do_brack brack)
82
  where
83
    new_bit = mkNameEnv [(n, Splice (unLoc e)) | (n,e) <- splices]
84

dreixel's avatar
dreixel committed
85
    do_brack (VarBr _ n) = do { MkC e1  <- lookupOcc n ; return e1 }
86 87 88 89 90
    do_brack (ExpBr e)   = do { MkC e1  <- repLE e     ; return e1 }
    do_brack (PatBr p)   = do { MkC p1  <- repTopP p   ; return p1 }
    do_brack (TypBr t)   = do { MkC t1  <- repLTy t    ; return t1 }
    do_brack (DecBrG gp) = do { MkC ds1 <- repTopDs gp ; return ds1 }
    do_brack (DecBrL _)  = panic "dsBracket: unexpected DecBrL"
91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106

{- -------------- Examples --------------------

  [| \x -> x |]
====>
  gensym (unpackString "x"#) `bindQ` \ x1::String ->
  lam (pvar x1) (var x1)


  [| \x -> $(f [| x |]) |]
====>
  gensym (unpackString "x"#) `bindQ` \ x1::String ->
  lam (pvar x1) (f (var x1))
-}


107 108 109 110
-------------------------------------------------------
-- 			Declarations
-------------------------------------------------------

111 112 113
repTopP :: LPat Name -> DsM (Core TH.PatQ)
repTopP pat = do { ss <- mkGenSyms (collectPatBinders pat) 
                 ; pat' <- addBinds ss (repLP pat)
114
                 ; wrapGenSyms ss pat' }
115

116
repTopDs :: HsGroup Name -> DsM (Core (TH.Q [TH.Dec]))
117
repTopDs group
118
 = do { let { bndrs = hsGroupBinders group } ;
119
	ss <- mkGenSyms bndrs ;
120

121 122 123 124 125
	-- Bind all the names mainly to avoid repeated use of explicit strings.
	-- Thus	we get
	--	do { t :: String <- genSym "T" ;
	--	     return (Data t [] ...more t's... }
	-- The other important reason is that the output must mention
126
	-- only "T", not "Foo:T" where Foo is the current module
127 128

	
129
	decls <- addBinds ss (do {
130
			val_ds  <- rep_val_binds (hs_valds group) ;
131
			tycl_ds <- mapM repTyClD (concat (hs_tyclds group)) ;
132
			inst_ds <- mapM repInstD (hs_instds group) ;
133
			for_ds <- mapM repForD (hs_fords group) ;
134
			-- more needed
135 136 137
			return (de_loc $ sort_by_loc $ 
                                val_ds ++ catMaybes tycl_ds
                                       ++ catMaybes inst_ds ++ for_ds) }) ;
138

139
	decl_ty <- lookupType decQTyConName ;
140
	let { core_list = coreList' decl_ty decls } ;
141 142 143

	dec_ty <- lookupType decTyConName ;
	q_decs  <- repSequenceQ dec_ty core_list ;
144

145
	wrapGenSyms ss q_decs
146 147 148
      }


149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166
{- 	Note [Binders and occurrences]
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When we desugar [d| data T = MkT |]
we want to get
	Data "T" [] [Con "MkT" []] []
and *not*
	Data "Foo:T" [] [Con "Foo:MkT" []] []
That is, the new data decl should fit into whatever new module it is
asked to fit in.   We do *not* clone, though; no need for this:
	Data "T79" ....

But if we see this:
	data T = MkT 
	foo = reifyDecl T

then we must desugar to
	foo = Data "Foo:T" [] [Con "Foo:MkT" []] []

167 168
So in repTopDs we bring the binders into scope with mkGenSyms and addBinds.
And we use lookupOcc, rather than lookupBinder
169 170 171 172
in repTyClD and repC.

-}

173
repTyClD :: LTyClDecl Name -> DsM (Maybe (SrcSpan, Core TH.DecQ))
174

175 176 177
repTyClD tydecl@(L _ (TyFamily {}))
  = repTyFamily tydecl addTyVarBinds

178
repTyClD (L loc (TyData { tcdND = DataType, tcdCtxt = cxt, 
179 180 181 182 183 184 185
		          tcdLName = tc, tcdTyVars = tvs, tcdTyPats = opt_tys,
		          tcdCons = cons, tcdDerivs = mb_derivs }))
  = do { tc1 <- lookupLOcc tc 		-- See note [Binders and occurrences] 
       ; dec <- addTyVarBinds tvs $ \bndrs -> 
           do { cxt1     <- repLContext cxt
              ; opt_tys1 <- maybeMapM repLTys opt_tys   -- only for family insts
              ; opt_tys2 <- maybeMapM (coreList typeQTyConName) opt_tys1
186
              ; cons1    <- mapM (repC (hsLTyVarNames tvs)) cons
187 188
      	      ; cons2    <- coreList conQTyConName cons1
      	      ; derivs1  <- repDerivs mb_derivs
189
	      ; bndrs1   <- coreList tyVarBndrTyConName bndrs
190 191 192 193
      	      ; repData cxt1 tc1 bndrs1 opt_tys2 cons2 derivs1 
              }
       ; return $ Just (loc, dec) 
       }
194

195
repTyClD (L loc (TyData { tcdND = NewType, tcdCtxt = cxt, 
196 197 198 199 200 201 202
		          tcdLName = tc, tcdTyVars = tvs, tcdTyPats = opt_tys,
		          tcdCons = [con], tcdDerivs = mb_derivs }))
  = do { tc1 <- lookupLOcc tc 		-- See note [Binders and occurrences] 
       ; dec <- addTyVarBinds tvs $ \bndrs -> 
           do { cxt1     <- repLContext cxt
              ; opt_tys1 <- maybeMapM repLTys opt_tys   -- only for family insts
              ; opt_tys2 <- maybeMapM (coreList typeQTyConName) opt_tys1
203
              ; con1     <- repC (hsLTyVarNames tvs) con
204
      	      ; derivs1  <- repDerivs mb_derivs
205
	      ; bndrs1   <- coreList tyVarBndrTyConName bndrs
206 207 208 209 210 211 212 213 214 215 216 217
      	      ; repNewtype cxt1 tc1 bndrs1 opt_tys2 con1 derivs1
              }
       ; return $ Just (loc, dec) 
       }

repTyClD (L loc (TySynonym { tcdLName = tc, tcdTyVars = tvs, tcdTyPats = opt_tys,
                             tcdSynRhs = ty }))
  = do { tc1 <- lookupLOcc tc 		-- See note [Binders and occurrences] 
       ; dec <- addTyVarBinds tvs $ \bndrs -> 
           do { opt_tys1 <- maybeMapM repLTys opt_tys   -- only for family insts
              ; opt_tys2 <- maybeMapM (coreList typeQTyConName) opt_tys1
	      ; ty1      <- repLTy ty
218
	      ; bndrs1   <- coreList tyVarBndrTyConName bndrs
219 220 221 222
	      ; repTySyn tc1 bndrs1 opt_tys2 ty1 
              }
       ; return (Just (loc, dec)) 
       }
223

224
repTyClD (L loc (ClassDecl { tcdCtxt = cxt, tcdLName = cls, 
225 226
		             tcdTyVars = tvs, tcdFDs = fds,
		             tcdSigs = sigs, tcdMeths = meth_binds, 
227
                             tcdATs = ats, tcdATDefs = [] }))
228 229 230 231 232 233 234 235
  = do { cls1 <- lookupLOcc cls 	-- See note [Binders and occurrences] 
       ; dec  <- addTyVarBinds tvs $ \bndrs -> 
           do { cxt1   <- repLContext cxt
 	      ; sigs1  <- rep_sigs sigs
 	      ; binds1 <- rep_binds meth_binds
	      ; fds1   <- repLFunDeps fds
              ; ats1   <- repLAssocFamilys ats
 	      ; decls1 <- coreList decQTyConName (ats1 ++ sigs1 ++ binds1)
236
	      ; bndrs1 <- coreList tyVarBndrTyConName bndrs
237 238 239 240
 	      ; repClass cxt1 cls1 bndrs1 fds1 decls1 
              }
       ; return $ Just (loc, dec) 
       }
241 242

-- Un-handled cases
243
repTyClD (L loc d) = putSrcSpanDs loc $
244
		     do { warnDs (hang ds_msg 4 (ppr d))
245
			; return Nothing }
246

247 248 249 250 251 252 253 254 255
-- The type variables in the head of families are treated differently when the
-- family declaration is associated.  In that case, they are usage, not binding
-- occurences.
--
repTyFamily :: LTyClDecl Name 
            -> ProcessTyVarBinds TH.Dec
            -> DsM (Maybe (SrcSpan, Core TH.DecQ))
repTyFamily (L loc (TyFamily { tcdFlavour = flavour,
		               tcdLName = tc, tcdTyVars = tvs, 
256
		               tcdKind = opt_kind }))
257 258 259 260
            tyVarBinds
  = do { tc1 <- lookupLOcc tc 		-- See note [Binders and occurrences] 
       ; dec <- tyVarBinds tvs $ \bndrs ->
           do { flav   <- repFamilyFlavour flavour
261 262 263 264 265 266
	      ; bndrs1 <- coreList tyVarBndrTyConName bndrs
              ; case opt_kind of 
                  Nothing -> repFamilyNoKind flav tc1 bndrs1
                  Just ki -> do { ki1 <- repKind ki 
                                ; repFamilyKind flav tc1 bndrs1 ki1
                                }
267 268 269 270 271
              }
       ; return $ Just (loc, dec)
       }
repTyFamily _ _ = panic "DsMeta.repTyFamily: internal error"

272 273 274 275 276 277 278 279 280 281 282 283 284
-- represent fundeps
--
repLFunDeps :: [Located (FunDep Name)] -> DsM (Core [TH.FunDep])
repLFunDeps fds = do fds' <- mapM repLFunDep fds
                     fdList <- coreList funDepTyConName fds'
                     return fdList

repLFunDep :: Located (FunDep Name) -> DsM (Core TH.FunDep)
repLFunDep (L _ (xs, ys)) = do xs' <- mapM lookupBinder xs
                               ys' <- mapM lookupBinder ys
                               xs_list <- coreList nameTyConName xs'
                               ys_list <- coreList nameTyConName ys'
                               repFunDep xs_list ys_list
285

286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
-- represent family declaration flavours
--
repFamilyFlavour :: FamilyFlavour -> DsM (Core TH.FamFlavour)
repFamilyFlavour TypeFamily = rep2 typeFamName []
repFamilyFlavour DataFamily = rep2 dataFamName []

-- represent associated family declarations
--
repLAssocFamilys :: [LTyClDecl Name] -> DsM [Core TH.DecQ]
repLAssocFamilys = mapM repLAssocFamily
  where
    repLAssocFamily tydecl@(L _ (TyFamily {})) 
      = liftM (snd . fromJust) $ repTyFamily tydecl lookupTyVarBinds
    repLAssocFamily tydecl
      = failWithDs msg
      where
        msg = ptext (sLit "Illegal associated declaration in class:") <+> 
              ppr tydecl

-- represent associated family instances
--
repLAssocFamInst :: [LTyClDecl Name] -> DsM [Core TH.DecQ]
repLAssocFamInst = liftM de_loc . mapMaybeM repTyClD

-- represent instance declarations
--
312 313 314 315 316 317
repInstD :: LInstDecl Name -> DsM (Maybe (SrcSpan, Core TH.DecQ))
repInstD (L loc (FamInstDecl fi_decl))
  = repTyClD (L loc fi_decl)


repInstD (L loc (ClsInstDecl ty binds _ ats))	-- Ignore user pragmas for now
318 319 320 321 322 323 324 325 326 327 328
  = do { dec <- addTyVarBinds tvs $ \_ ->
	    -- We must bring the type variables into scope, so their
	    -- occurrences don't fail, even though the binders don't 
            -- appear in the resulting data structure
	    --
	    -- But we do NOT bring the binders of 'binds' into scope
	    -- becuase they are properly regarded as occurrences
	    -- For example, the method names should be bound to
	    -- the selector Ids, not to fresh names (Trac #5410)
	    --
            do { cxt1 <- repContext cxt
batterseapower's avatar
batterseapower committed
329 330 331
               ; cls_tcon <- repTy (HsTyVar cls)
               ; cls_tys <- repLTys tys
               ; inst_ty1 <- repTapps cls_tcon cls_tys
332 333 334 335
               ; binds1 <- rep_binds binds
               ; ats1 <- repLAssocFamInst ats
               ; decls <- coreList decQTyConName (ats1 ++ binds1)
               ; repInst cxt1 inst_ty1 decls }
336
       ; return (Just (loc, dec)) }
337
 where
batterseapower's avatar
batterseapower committed
338
   Just (tvs, cxt, cls, tys) = splitHsInstDeclTy_maybe (unLoc ty)
339

340
repForD :: Located (ForeignDecl Name) -> DsM (SrcSpan, Core TH.DecQ)
341
repForD (L loc (ForeignImport name typ _ (CImport cc s ch cis)))
342 343 344 345
 = do MkC name' <- lookupLOcc name
      MkC typ' <- repLTy typ
      MkC cc' <- repCCallConv cc
      MkC s' <- repSafety s
346
      cis' <- conv_cimportspec cis
347 348
      MkC str <- coreStringLit $ static
                              ++ unpackFS ch ++ " "
349
                              ++ cis'
350 351 352
      dec <- rep2 forImpDName [cc', s', str, name', typ']
      return (loc, dec)
 where
353 354
    conv_cimportspec (CLabel cls) = notHandled "Foreign label" (doubleQuotes (ppr cls))
    conv_cimportspec (CFunction DynamicTarget) = return "dynamic"
355
    conv_cimportspec (CFunction (StaticTarget fs _)) = return (unpackFS fs)
356
    conv_cimportspec CWrapper = return "wrapper"
357
    static = case cis of
358
                 CFunction (StaticTarget _ _) -> "static "
359
                 _ -> ""
360
repForD decl = notHandled "Foreign declaration" (ppr decl)
361 362 363 364

repCCallConv :: CCallConv -> DsM (Core TH.Callconv)
repCCallConv CCallConv = rep2 cCallName []
repCCallConv StdCallConv = rep2 stdCallName []
365
repCCallConv callConv    = notHandled "repCCallConv" (ppr callConv)
366 367 368

repSafety :: Safety -> DsM (Core TH.Safety)
repSafety PlayRisky = rep2 unsafeName []
369
repSafety PlayInterruptible = rep2 interruptibleName []
Ian Lynagh's avatar
Ian Lynagh committed
370
repSafety PlaySafe = rep2 safeName []
371

Ian Lynagh's avatar
Ian Lynagh committed
372
ds_msg :: SDoc
Ian Lynagh's avatar
Ian Lynagh committed
373
ds_msg = ptext (sLit "Cannot desugar this Template Haskell declaration:")
374

375 376 377 378
-------------------------------------------------------
-- 			Constructors
-------------------------------------------------------

379 380 381
repC :: [Name] -> LConDecl Name -> DsM (Core TH.ConQ)
repC _ (L _ (ConDecl { con_name = con, con_qvars = [], con_cxt = L _ []
                       , con_details = details, con_res = ResTyH98 }))
382
  = do { con1 <- lookupLOcc con 	-- See note [Binders and occurrences] 
383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438
       ; repConstr con1 details  }
repC tvs (L _ (ConDecl { con_name = con
                       , con_qvars = con_tvs, con_cxt = L _ ctxt
                       , con_details = details
                       , con_res = res_ty }))
  = do { (eq_ctxt, con_tv_subst) <- mkGadtCtxt tvs res_ty
       ; let ex_tvs = [ tv | tv <- con_tvs, not (hsLTyVarName tv `in_subst` con_tv_subst)]
       ; binds <- mapM dupBinder con_tv_subst 
       ; dsExtendMetaEnv (mkNameEnv binds) $     -- Binds some of the con_tvs
         addTyVarBinds ex_tvs $ \ ex_bndrs ->   -- Binds the remaining con_tvs
    do { con1      <- lookupLOcc con 	-- See note [Binders and occurrences] 
       ; c'        <- repConstr con1 details
       ; ctxt'     <- repContext (eq_ctxt ++ ctxt)
       ; ex_bndrs' <- coreList tyVarBndrTyConName ex_bndrs
       ; rep2 forallCName [unC ex_bndrs', unC ctxt', unC c'] } }

in_subst :: Name -> [(Name,Name)] -> Bool
in_subst _ []          = False
in_subst n ((n',_):ns) = n==n' || in_subst n ns

mkGadtCtxt :: [Name]		-- Tyvars of the data type
           -> ResType Name
	   -> DsM (HsContext Name, [(Name,Name)])
-- Given a data type in GADT syntax, figure out the equality 
-- context, so that we can represent it with an explicit 
-- equality context, because that is the only way to express
-- the GADT in TH syntax
--
-- Example:   
-- data T a b c where { MkT :: forall d e. d -> e -> T d [e] e
--     mkGadtCtxt [a,b,c] [d,e] (T d [e] e)
--   returns 
--     (b~[e], c~e), [d->a] 
-- 
-- This function is fiddly, but not really hard
mkGadtCtxt _ ResTyH98
  = return ([], [])
mkGadtCtxt data_tvs (ResTyGADT res_ty)
  | let (head_ty, tys) = splitHsAppTys res_ty []
  , Just _ <- is_hs_tyvar head_ty
  , data_tvs `equalLength` tys
  = return (go [] [] (data_tvs `zip` tys))

  | otherwise 
  = failWithDs (ptext (sLit "Malformed constructor result type") <+> ppr res_ty)
  where
    go cxt subst [] = (cxt, subst)
    go cxt subst ((data_tv, ty) : rest)
       | Just con_tv <- is_hs_tyvar ty
       , isTyVarName con_tv
       , not (in_subst con_tv subst)
       = go cxt ((con_tv, data_tv) : subst) rest
       | otherwise
       = go (eq_pred : cxt) subst rest
       where
         loc = getLoc ty
batterseapower's avatar
batterseapower committed
439
         eq_pred = L loc (HsEqTy (L loc (HsTyVar data_tv)) ty)
440 441 442 443 444 445

    is_hs_tyvar (L _ (HsTyVar n))  = Just n   -- Type variables *and* tycons
    is_hs_tyvar (L _ (HsParTy ty)) = is_hs_tyvar ty
    is_hs_tyvar _                  = Nothing

    
446
repBangTy :: LBangType Name -> DsM (Core (TH.StrictTypeQ))
447 448 449
repBangTy ty= do 
  MkC s <- rep2 str []
  MkC t <- repLTy ty'
450
  rep2 strictTypeName [s, t]
451 452
  where 
    (str, ty') = case ty of
453 454 455
		   L _ (HsBangTy HsUnpack ty) -> (unpackedName,  ty)
		   L _ (HsBangTy _ ty)        -> (isStrictName,  ty)
		   _                          -> (notStrictName, ty)
456 457 458 459 460

-------------------------------------------------------
-- 			Deriving clause
-------------------------------------------------------

461
repDerivs :: Maybe [LHsType Name] -> DsM (Core [TH.Name])
462
repDerivs Nothing = coreList nameTyConName []
463
repDerivs (Just ctxt)
464
  = do { strs <- mapM rep_deriv ctxt ; 
465
	 coreList nameTyConName strs }
466
  where
467
    rep_deriv :: LHsType Name -> DsM (Core TH.Name)
468
	-- Deriving clauses must have the simple H98 form
batterseapower's avatar
batterseapower committed
469 470 471 472 473
    rep_deriv ty
      | Just (cls, []) <- splitHsClassTy_maybe (unLoc ty)
      = lookupOcc cls
      | otherwise
      = notHandled "Non-H98 deriving clause" (ppr ty)
474 475 476 477 478 479


-------------------------------------------------------
--   Signatures in a class decl, or a group of bindings
-------------------------------------------------------

480
rep_sigs :: [LSig Name] -> DsM [Core TH.DecQ]
481 482 483
rep_sigs sigs = do locs_cores <- rep_sigs' sigs
                   return $ de_loc $ sort_by_loc locs_cores

484
rep_sigs' :: [LSig Name] -> DsM [(SrcSpan, Core TH.DecQ)]
485
	-- We silently ignore ones we don't recognise
486
rep_sigs' sigs = do { sigs1 <- mapM rep_sig sigs ;
487 488
		     return (concat sigs1) }

489
rep_sig :: LSig Name -> DsM [(SrcSpan, Core TH.DecQ)]
490 491
	-- Singleton => Ok
	-- Empty     => Too hard, signature ignored
492
rep_sig (L loc (TypeSig nms ty))      = rep_proto nms ty loc
dreixel's avatar
dreixel committed
493 494 495 496
rep_sig (L _   (GenericSig nm _))     = failWithDs msg
  where msg = vcat  [ ptext (sLit "Illegal default signature for") <+> quotes (ppr nm)
                    , ptext (sLit "Default signatures are not supported by Template Haskell") ]

497 498 499 500
rep_sig (L loc (InlineSig nm ispec))  = rep_inline nm ispec loc
rep_sig (L loc (SpecSig nm ty ispec)) = rep_specialise nm ty ispec loc
rep_sig _                             = return []

501
rep_proto :: [Located Name] -> LHsType Name -> SrcSpan
502
          -> DsM [(SrcSpan, Core TH.DecQ)]
503 504 505 506 507 508 509 510
rep_proto nms ty loc
  = mapM f nms
  where
    f nm = do { nm1 <- lookupLOcc nm
              ; ty1 <- repLTy ty
              ; sig <- repProto nm1 ty1
              ; return (loc, sig)
              }
511

512 513 514
rep_inline :: Located Name 
           -> InlinePragma	-- Never defaultInlinePragma
           -> SrcSpan 
515 516 517
           -> DsM [(SrcSpan, Core TH.DecQ)]
rep_inline nm ispec loc
  = do { nm1 <- lookupLOcc nm
518
       ; ispec1 <- rep_InlinePrag ispec
519 520 521 522
       ; pragma <- repPragInl nm1 ispec1
       ; return [(loc, pragma)]
       }

523
rep_specialise :: Located Name -> LHsType Name -> InlinePragma -> SrcSpan 
524 525 526 527
               -> DsM [(SrcSpan, Core TH.DecQ)]
rep_specialise nm ty ispec loc
  = do { nm1 <- lookupLOcc nm
       ; ty1 <- repLTy ty
528 529 530 531
       ; pragma <- if isDefaultInlinePragma ispec
                   then repPragSpec nm1 ty1                  -- SPECIALISE
                   else do { ispec1 <- rep_InlinePrag ispec  -- SPECIALISE INLINE
                           ; repPragSpecInl nm1 ty1 ispec1 } 
532 533
       ; return [(loc, pragma)]
       }
534

535
-- Extract all the information needed to build a TH.InlinePrag
536
--
537 538 539
rep_InlinePrag :: InlinePragma	-- Never defaultInlinePragma
               -> DsM (Core TH.InlineSpecQ)
rep_InlinePrag (InlinePragma { inl_act = activation, inl_rule = match, inl_inline = inline })
540
  | Just (flag, phase) <- activation1 
541 542 543 544
  = repInlineSpecPhase inline1 match1 flag phase
  | otherwise
  = repInlineSpecNoPhase inline1 match1
  where
545 546
      match1      = coreBool (rep_RuleMatchInfo match)
      activation1 = rep_Activation activation
547 548 549 550
      inline1     = case inline of 
                       Inline -> coreBool True
 		       _other -> coreBool False
		       -- We have no representation for Inlinable
551 552 553 554

      rep_RuleMatchInfo FunLike = False
      rep_RuleMatchInfo ConLike = True

555 556
      rep_Activation NeverActive          = Nothing	-- We never have NOINLINE/AlwaysActive
      rep_Activation AlwaysActive         = Nothing	-- or            INLINE/NeverActive
557 558 559 560
      rep_Activation (ActiveBefore phase) = Just (coreBool False, 
                                                  MkC $ mkIntExprInt phase)
      rep_Activation (ActiveAfter phase)  = Just (coreBool True, 
                                                  MkC $ mkIntExprInt phase)
561 562 563 564 565


-------------------------------------------------------
-- 			Types
-------------------------------------------------------
566

567 568 569 570 571
-- We process type variable bindings in two ways, either by generating fresh
-- names or looking up existing names.  The difference is crucial for type
-- families, depending on whether they are associated or not.
--
type ProcessTyVarBinds a = 
572 573
         [LHsTyVarBndr Name]	                       -- the binders to be added
      -> ([Core TH.TyVarBndr] -> DsM (Core (TH.Q a)))  -- action in the ext env
574 575
      -> DsM (Core (TH.Q a))

576 577
-- gensym a list of type variables and enter them into the meta environment;
-- the computations passed as the second argument is executed in that extended
578
-- meta environment and gets the *new* names on Core-level as an argument
579
--
580
addTyVarBinds :: ProcessTyVarBinds a
581 582 583 584 585 586 587 588
addTyVarBinds tvs m
  = do { freshNames <- mkGenSyms (hsLTyVarNames tvs)
       ; term <- addBinds freshNames $ 
	    	 do { kindedBndrs <- mapM mk_tv_bndr (tvs `zip` freshNames)
	    	    ; m kindedBndrs }
       ; wrapGenSyms freshNames term }
  where
    mk_tv_bndr (tv, (_,v)) = repTyVarBndrWithKind tv (coreVar v)
589

590 591 592 593 594 595
-- Look up a list of type variables; the computations passed as the second 
-- argument gets the *new* names on Core-level as an argument
--
lookupTyVarBinds :: ProcessTyVarBinds a
lookupTyVarBinds tvs m =
  do
596 597 598 599 600 601 602 603 604 605
    let names       = hsLTyVarNames tvs
        mkWithKinds = map repTyVarBndrWithKind tvs
    bndrs       <- mapM lookupBinder names 
    kindedBndrs <- zipWithM ($) mkWithKinds bndrs
    m kindedBndrs

-- Produce kinded binder constructors from the Haskell tyvar binders
--
repTyVarBndrWithKind :: LHsTyVarBndr Name 
                     -> Core TH.Name -> DsM (Core TH.TyVarBndr)
606 607
repTyVarBndrWithKind (L _ (UserTyVar {})) nm
  = repPlainTV nm
dreixel's avatar
dreixel committed
608
repTyVarBndrWithKind (L _ (KindedTyVar _ ki _)) nm
609
  = repKind ki >>= repKindedTV nm
610

611 612
-- represent a type context
--
613 614 615
repLContext :: LHsContext Name -> DsM (Core TH.CxtQ)
repLContext (L _ ctxt) = repContext ctxt

616
repContext :: HsContext Name -> DsM (Core TH.CxtQ)
617
repContext ctxt = do 
618
	            preds    <- mapM repLPred ctxt
619
		    predList <- coreList predQTyConName preds
620
		    repCtxt predList
621

622 623
-- represent a type predicate
--
batterseapower's avatar
batterseapower committed
624
repLPred :: LHsType Name -> DsM (Core TH.PredQ)
625 626
repLPred (L _ p) = repPred p

batterseapower's avatar
batterseapower committed
627 628 629
repPred :: HsType Name -> DsM (Core TH.PredQ)
repPred ty
  | Just (cls, tys) <- splitHsClassTy_maybe ty
630 631 632 633 634
  = do
      cls1 <- lookupOcc cls
      tys1 <- repLTys tys
      tys2 <- coreList typeQTyConName tys1
      repClassP cls1 tys2
batterseapower's avatar
batterseapower committed
635
repPred (HsEqTy tyleft tyright) 
636 637 638 639
  = do
      tyleft1  <- repLTy tyleft
      tyright1 <- repLTy tyright
      repEqualP tyleft1 tyright1
batterseapower's avatar
batterseapower committed
640 641
repPred ty
  = notHandled "Exotic predicate type" (ppr ty)
642

643 644
-- yield the representation of a list of types
--
645 646
repLTys :: [LHsType Name] -> DsM [Core TH.TypeQ]
repLTys tys = mapM repLTy tys
647

648 649
-- represent a type
--
650 651 652
repLTy :: LHsType Name -> DsM (Core TH.TypeQ)
repLTy (L _ ty) = repTy ty

653 654 655
repTy :: HsType Name -> DsM (Core TH.TypeQ)
repTy (HsForAllTy _ tvs ctxt ty)  = 
  addTyVarBinds tvs $ \bndrs -> do
656 657
    ctxt1  <- repLContext ctxt
    ty1    <- repLTy ty
658
    bndrs1 <- coreList tyVarBndrTyConName bndrs
659
    repTForall bndrs1 ctxt1 ty1
660

661
repTy (HsTyVar n)
662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
  | isTvOcc (nameOccName n) = do 
			        tv1 <- lookupTvOcc n
			        repTvar tv1
  | otherwise		    = do 
			        tc1 <- lookupOcc n
			        repNamedTyCon tc1
repTy (HsAppTy f a)         = do 
			        f1 <- repLTy f
			        a1 <- repLTy a
			        repTapp f1 a1
repTy (HsFunTy f a)         = do 
			        f1   <- repLTy f
			        a1   <- repLTy a
			        tcon <- repArrowTyCon
			        repTapps tcon [f1, a1]
repTy (HsListTy t)	    = do
			        t1   <- repLTy t
			        tcon <- repListTyCon
			        repTapp tcon t1
repTy (HsPArrTy t)          = do
			        t1   <- repLTy t
			        tcon <- repTy (HsTyVar (tyConName parrTyCon))
			        repTapp tcon t1
batterseapower's avatar
batterseapower committed
685
repTy (HsTupleTy HsUnboxedTuple tys) = do
686 687 688
			        tys1 <- repLTys tys
			        tcon <- repUnboxedTupleTyCon (length tys)
			        repTapps tcon tys1
689 690 691
repTy (HsTupleTy _ tys)     = do tys1 <- repLTys tys 
                                 tcon <- repTupleTyCon (length tys)
                                 repTapps tcon tys1
dreixel's avatar
dreixel committed
692
repTy (HsOpTy ty1 (_, n) ty2) = repLTy ((nlHsTyVar (unLoc n) `nlHsAppTy` ty1)
693 694 695 696 697 698
			    	   `nlHsAppTy` ty2)
repTy (HsParTy t)  	    = repLTy t
repTy (HsKindSig t k)       = do
                                t1 <- repLTy t
                                k1 <- repKind k
                                repTSig t1 k1
699 700
repTy (HsSpliceTy splice _ _) = repSplice splice
repTy ty		      = notHandled "Exotic form of type" (ppr ty)
701

702 703
-- represent a kind
--
dreixel's avatar
dreixel committed
704
repKind :: LHsKind Name -> DsM (Core TH.Kind)
705
repKind ki
dreixel's avatar
dreixel committed
706
  = do { let (kis, ki') = splitHsFunType ki
707 708
       ; kis_rep <- mapM repKind kis
       ; ki'_rep <- repNonArrowKind ki'
709
       ; foldrM repArrowK ki'_rep kis_rep
710 711
       }
  where
dreixel's avatar
dreixel committed
712 713
    repNonArrowKind (L _ (HsTyVar name)) | name == liftedTypeKindTyConName = repStarK
    repNonArrowKind k = notHandled "Exotic form of kind" (ppr k)
714

715 716 717 718 719 720 721 722 723 724 725 726 727 728 729
-----------------------------------------------------------------------------
-- 		Splices
-----------------------------------------------------------------------------

repSplice :: HsSplice Name -> DsM (Core a)
-- See Note [How brackets and nested splices are handled] in TcSplice
-- We return a CoreExpr of any old type; the context should know
repSplice (HsSplice n _) 
 = do { mb_val <- dsLookupMetaEnv n
       ; case mb_val of
	   Just (Splice e) -> do { e' <- dsExpr e
				 ; return (MkC e') }
	   _ -> pprPanic "HsSplice" (ppr n) }
			-- Should not happen; statically checked

730
-----------------------------------------------------------------------------
731
-- 		Expressions
732
-----------------------------------------------------------------------------
733

734 735 736
repLEs :: [LHsExpr Name] -> DsM (Core [TH.ExpQ])
repLEs es = do { es'  <- mapM repLE es ;
		 coreList expQTyConName es' }
737

738 739 740
-- FIXME: some of these panics should be converted into proper error messages
--	  unless we can make sure that constructs, which are plainly not
--	  supported in TH already lead to error messages at an earlier stage
741
repLE :: LHsExpr Name -> DsM (Core TH.ExpQ)
742
repLE (L loc e) = putSrcSpanDs loc (repE e)
743

744
repE :: HsExpr Name -> DsM (Core TH.ExpQ)
745 746 747
repE (HsVar x)            =
  do { mb_val <- dsLookupMetaEnv x 
     ; case mb_val of
748
	Nothing	         -> do { str <- globalVar x
749 750 751 752
			       ; repVarOrCon x str }
	Just (Bound y)   -> repVarOrCon x (coreVar y)
	Just (Splice e)  -> do { e' <- dsExpr e
			       ; return (MkC e') } }
Ian Lynagh's avatar
Ian Lynagh committed
753
repE e@(HsIPVar _) = notHandled "Implicit parameters" (ppr e)
754 755 756 757 758

	-- Remember, we're desugaring renamer output here, so
	-- HsOverlit can definitely occur
repE (HsOverLit l) = do { a <- repOverloadedLiteral l; repLit a }
repE (HsLit l)     = do { a <- repLiteral l;           repLit a }
759
repE (HsLam (MatchGroup [m] _)) = repLambda m
760
repE (HsApp x y)   = do {a <- repLE x; b <- repLE y; repApp a b}
761

Ian Lynagh's avatar
Ian Lynagh committed
762
repE (OpApp e1 op _ e2) =
763 764 765
  do { arg1 <- repLE e1; 
       arg2 <- repLE e2; 
       the_op <- repLE op ;
766
       repInfixApp arg1 the_op arg2 } 
Ian Lynagh's avatar
Ian Lynagh committed
767
repE (NegApp x _)        = do
768
			      a         <- repLE x
769 770
			      negateVar <- lookupOcc negateName >>= repVar
			      negateVar `repApp` a
771 772 773
repE (HsPar x)            = repLE x
repE (SectionL x y)       = do { a <- repLE x; b <- repLE y; repSectionL a b } 
repE (SectionR x y)       = do { a <- repLE x; b <- repLE y; repSectionR a b } 
774 775 776
repE (HsCase e (MatchGroup ms _)) = do { arg <- repLE e
				       ; ms2 <- mapM repMatchTup ms
				       ; repCaseE arg (nonEmptyCoreList ms2) }
777
repE (HsIf _ x y z)         = do
778 779 780
			      a <- repLE x
			      b <- repLE y
			      c <- repLE z
781 782
			      repCond a b c
repE (HsLet bs e)         = do { (ss,ds) <- repBinds bs
783
			       ; e2 <- addBinds ss (repLE e)
784
			       ; z <- repLetE ds e2
785
			       ; wrapGenSyms ss z }
786

787
-- FIXME: I haven't got the types here right yet
788
repE e@(HsDo ctxt sts _) 
789
 | case ctxt of { DoExpr -> True; GhciStmt -> True; _ -> False }
790
 = do { (ss,zs) <- repLSts sts; 
791
        e'      <- repDoE (nonEmptyCoreList zs);
792
        wrapGenSyms ss e' }
793 794

 | ListComp <- ctxt
795
 = do { (ss,zs) <- repLSts sts; 
796
        e'      <- repComp (nonEmptyCoreList zs);
797
        wrapGenSyms ss e' }
798 799

  | otherwise
800
  = notHandled "mdo, monad comprehension and [: :]" (ppr e)
801

Ian Lynagh's avatar
Ian Lynagh committed
802 803
repE (ExplicitList _ es) = do { xs <- repLEs es; repListExp xs }
repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
804
repE e@(ExplicitTuple es boxed) 
805
  | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
806 807
  | isBoxed boxed              = do { xs <- repLEs [e | Present e <- es]; repTup xs }
  | otherwise                  = do { xs <- repLEs [e | Present e <- es]; repUnboxedTup xs }
808

809
repE (RecordCon c _ flds)
810
 = do { x <- lookupLOcc c;
811 812
        fs <- repFields flds;
        repRecCon x fs }
813
repE (RecordUpd e flds _ _ _)
814
 = do { x <- repLE e;
815 816
        fs <- repFields flds;
        repRecUpd x fs }
817

818
repE (ExprWithTySig e ty) = do { e1 <- repLE e; t1 <- repLTy ty; repSigExp e1 t1 }
819
repE (ArithSeq _ aseq) =
820
  case aseq of
821
    From e              -> do { ds1 <- repLE e; repFrom ds1 }
822
    FromThen e1 e2      -> do 
823 824
		             ds1 <- repLE e1
			     ds2 <- repLE e2
825 826
			     repFromThen ds1 ds2
    FromTo   e1 e2      -> do 
827 828
			     ds1 <- repLE e1
			     ds2 <- repLE e2
829 830
			     repFromTo ds1 ds2
    FromThenTo e1 e2 e3 -> do 
831 832 833
			     ds1 <- repLE e1
			     ds2 <- repLE e2
			     ds3 <- repLE e3
834
			     repFromThenTo ds1 ds2 ds3
835

836
repE (HsSpliceE splice)  = repSplice splice
837 838 839
repE e@(PArrSeq {})      = notHandled "Parallel arrays" (ppr e)
repE e@(HsCoreAnn {})    = notHandled "Core annotations" (ppr e)
repE e@(HsSCC {})        = notHandled "Cost centres" (ppr e)
andy@galois.com's avatar
andy@galois.com committed
840
repE e@(HsTickPragma {}) = notHandled "Tick Pragma" (ppr e)
841 842
repE e@(HsBracketOut {}) = notHandled "TH brackets" (ppr e)
repE e 			 = notHandled "Expression form" (ppr e)
843 844 845 846

-----------------------------------------------------------------------------
-- Building representations of auxillary structures like Match, Clause, Stmt, 

847
repMatchTup ::  LMatch Name -> DsM (Core TH.MatchQ) 
Ian Lynagh's avatar
Ian Lynagh committed
848
repMatchTup (L _ (Match [p] _ (GRHSs guards wheres))) =
849
  do { ss1 <- mkGenSyms (collectPatBinders p) 
850
     ; addBinds ss1 $ do {
851
     ; p1 <- repLP p
852
     ; (ss2,ds) <- repBinds wheres
853 854 855
     ; addBinds ss2 $ do {
     ; gs    <- repGuards guards
     ; match <- repMatch p1 gs ds
856
     ; wrapGenSyms (ss1++ss2) match }}}
Ian Lynagh's avatar
Ian Lynagh committed
857
repMatchTup _ = panic "repMatchTup: case alt with more than one arg"
858

859
repClauseTup ::  LMatch Name -> DsM (Core TH.ClauseQ)
Ian Lynagh's avatar
Ian Lynagh committed
860
repClauseTup (L _ (Match ps _ (GRHSs guards wheres))) =
861
  do { ss1 <- mkGenSyms (collectPatsBinders ps) 
862
     ; addBinds ss1 $ do {
863
       ps1 <- repLPs ps
864
     ; (ss2,ds) <- repBinds wheres
865 866 867
     ; addBinds ss2 $ do {
       gs <- repGuards guards
     ; clause <- repClause ps1 gs ds
868
     ; wrapGenSyms (ss1++ss2) clause }}}
869

870
repGuards ::  [LGRHS Name] ->  DsM (Core TH.BodyQ)
871
repGuards [L _ (GRHS [] e)]
872
  = do {a <- repLE e; repNormal a }
873
repGuards other 
874 875 876
  = do { zs <- mapM process other;
     let {(xs, ys) = unzip zs};
	 gd <- repGuarded (nonEmptyCoreList ys);
877
     wrapGenSyms (concat xs) gd }
878
  where 
879
    process :: LGRHS Name -> DsM ([GenSymBind], (Core (TH.Q (TH.Guard, TH.Exp))))
880
    process (L _ (GRHS [L _ (ExprStmt e1 _ _ _)] e2))
881 882
           = do { x <- repLNormalGE e1 e2;
                  return ([], x) }
883
    process (L _ (GRHS ss rhs))
884
           = do (gs, ss') <- repLSts ss
885
		rhs' <- addBinds gs $ repLE rhs
886
                g <- repPatGE (nonEmptyCoreList ss') rhs'
887
                return (gs, g)
888

889 890
repFields :: HsRecordBinds Name -> DsM (Core [TH.Q TH.FieldExp])
repFields (HsRecFields { rec_flds = flds })
891 892 893 894
  = do	{ fnames <- mapM lookupLOcc (map hsRecFieldId flds)
	; es <- mapM repLE (map hsRecFieldArg flds)
	; fs <- zipWithM repFieldExp fnames es
	; coreList fieldExpQTyConName fs }
895

896 897 898

-----------------------------------------------------------------------------
-- Representing Stmt's is tricky, especially if bound variables
899
-- shadow each other. Consider:  [| do { x <- f 1; x <- f x; g x } |]
900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921
-- First gensym new names for every variable in any of the patterns.
-- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y"))
-- if variables didn't shaddow, the static gensym wouldn't be necessary
-- and we could reuse the original names (x and x).
--
-- do { x'1 <- gensym "x"
--    ; x'2 <- gensym "x"   
--    ; doE [ BindSt (pvar x'1) [| f 1 |]
--          , BindSt (pvar x'2) [| f x |] 
--          , NoBindSt [| g x |] 
--          ]
--    }

-- The strategy is to translate a whole list of do-bindings by building a
-- bigger environment, and a bigger set of meta bindings 
-- (like:  x'1 <- gensym "x" ) and then combining these with the translations
-- of the expressions within the Do
      
-----------------------------------------------------------------------------
-- The helper function repSts computes the translation of each sub expression
-- and a bunch of prefix bindings denoting the dynamic renaming.

922 923 924
repLSts :: [LStmt Name] -> DsM ([GenSymBind], [Core TH.StmtQ])
repLSts stmts = repSts (map unLoc stmts)

925
repSts :: [Stmt Name] -> DsM ([GenSymBind], [Core TH.StmtQ])
926
repSts (BindStmt p e _ _ : ss) =
927
   do { e2 <- repLE e 
928
      ; ss1 <- mkGenSyms (collectPatBinders p) 
929
      ; addBinds ss1 $ do {
930
      ; p1 <- repLP p; 
931 932 933 934
      ; (ss2,zs) <- repSts ss
      ; z <- repBindSt p1 e2
      ; return (ss1++ss2, z : zs) }}
repSts (LetStmt bs : ss) =
935
   do { (ss1,ds) <- repBinds bs
936 937 938
      ; z <- repLetSt ds
      ; (ss2,zs) <- addBinds ss1 (repSts ss)
      ; return (ss1++ss2, z : zs) } 
939
repSts (ExprStmt e _ _ _ : ss) =       
940
   do { e2 <- repLE e
941 942 943
      ; z <- repNoBindSt e2 
      ; (ss2,zs) <- repSts ss
      ; return (ss2, z : zs) }
944 945 946 947
repSts [LastStmt e _] 
  = do { e2 <- repLE e
       ; z <- repNoBindSt e2
       ; return ([], [z]) }
948 949
repSts []    = return ([],[])
repSts other = notHandled "Exotic statement" (ppr other)
950 951


952 953 954
-----------------------------------------------------------
--			Bindings
-----------------------------------------------------------
955

956 957 958 959 960
repBinds :: HsLocalBinds Name -> DsM ([GenSymBind], Core [TH.DecQ]) 
repBinds EmptyLocalBinds
  = do	{ core_list <- coreList decQTyConName []
	; return ([], core_list) }

961
repBinds b@(HsIPBinds _) = notHandled "Implicit parameters" (ppr b)
962 963

repBinds (HsValBinds decs)
964
 = do	{ let { bndrs = collectHsValBinders decs }
965 966 967 968
		-- No need to worrry about detailed scopes within
		-- the binding group, because we are talking Names
		-- here, so we can safely treat it as a mutually 
		-- recursive group
969
	; ss        <- mkGenSyms bndrs
970 971 972
	; prs       <- addBinds ss (rep_val_binds decs)
	; core_list <- coreList decQTyConName 
				(de_loc (sort_by_loc prs))
973
	; return (ss, core_list) }
974

975
rep_val_binds :: HsValBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
976
-- Assumes: all the binders of the binding are alrady in the meta-env
977 978
rep_val_binds (ValBindsOut binds sigs)
 = do { core1 <- rep_binds' (unionManyBags (map snd binds))
979
      ;	core2 <- rep_sigs' sigs
980
      ;	return (core1 ++ core2) }
Ian Lynagh's avatar
Ian Lynagh committed
981
rep_val_binds (ValBindsIn _ _)
982
 = panic "rep_val_binds: ValBindsIn"
983

984
rep_binds :: LHsBinds Name -> DsM [Core TH.DecQ]
985 986 987 988 989
rep_binds binds = do { binds_w_locs <- rep_binds' binds
		     ; return (de_loc (sort_by_loc binds_w_locs)) }

rep_binds' :: LHsBinds Name -> DsM [(SrcSpan, Core TH.DecQ)]
rep_binds' binds = mapM rep_bind (bagToList binds)
990

991
rep_bind :: LHsBind Name -> DsM (SrcSpan, Core TH.DecQ)
992
-- Assumes: all the binders of the binding are alrady in the meta-env
993 994 995 996

-- Note GHC treats declarations of a variable (not a pattern) 
-- e.g.  x = g 5 as a Fun MonoBinds. This is indicated by a single match 
-- with an empty list of patterns
997
rep_bind (L loc (FunBind { fun_id = fn, 
Ian Lynagh's avatar
Ian Lynagh committed
998
			   fun_matches = MatchGroup [L _ (Match [] _ (GRHSs guards wheres))] _ }))
999
 = do { (ss,wherecore) <- repBinds wheres
1000
	; guardcore <- addBinds ss (repGuards guards)
1001 1002 1003
	; fn'  <- lookupLBinder fn
	; p    <- repPvar fn'
	; ans  <- repVal p guardcore wherecore
1004
	; ans' <- wrapGenSyms ss ans
1005
	; return (loc, ans') }
1006

1007
rep_bind (L loc (FunBind { fun_id = fn, fun_matches = MatchGroup ms _ }))
1008
 =   do { ms1 <- mapM repClauseTup ms
1009
	; fn' <- lookupLBinder fn
1010
        ; ans <- repFun fn' (nonEmptyCoreList ms1)
1011
        ; return (loc, ans) }
1012

1013
rep_bind (L loc (PatBind { pat_lhs = pat, pat_rhs = GRHSs guards wheres }))
1014
 =   do { patcore <- repLP pat 
1015
        ; (ss,wherecore) <- repBinds wheres
1016
	; guardcore <- addBinds ss (repGuards guards)
1017
        ; ans  <- repVal patcore guardcore wherecore
1018
	; ans' <- wrapGenSyms ss ans
1019
        ; return (loc, ans') }
1020

Ian Lynagh's avatar
Ian Lynagh committed
1021
rep_bind (L _ (VarBind { var_id = v, var_rhs = e}))
1022
 =   do { v' <- lookupBinder v 
1023
	; e2 <- repLE e
1024 1025
        ; x <- repNormal e2
        ; patcore <- repPvar v'
1026
	; empty_decls <- coreList decQTyConName [] 
1027
        ; ans <- repVal patcore x empty_decls
1028
        ; return (srcLocSpan (getSrcLoc v), ans) }
1029