aboutsummaryrefslogtreecommitdiff
path: root/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
blob: f3e29d9d337da252b73eb6064c0d6197e7a2ed23 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
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
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
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
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
{-# LANGUAGE TransformListComp #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  Haddock.Backends.Html.Decl
-- Copyright   :  (c) Simon Marlow   2003-2006,
--                    David Waern    2006-2009,
--                    Mark Lentczner 2010
-- License     :  BSD-like
--
-- Maintainer  :  haddock@projects.haskell.org
-- Stability   :  experimental
-- Portability :  portable
-----------------------------------------------------------------------------
module Haddock.Backends.Xhtml.Decl (
  ppDecl,

  ppTyName, ppTyFamHeader, ppTypeApp,
  tyvarNames
) where


import Haddock.Backends.Xhtml.DocMarkup
import Haddock.Backends.Xhtml.Layout
import Haddock.Backends.Xhtml.Names
import Haddock.Backends.Xhtml.Types
import Haddock.Backends.Xhtml.Utils
import Haddock.GhcUtils
import Haddock.Types
import Haddock.Doc (combineDocumentation)

import           Control.Applicative
import           Data.List             ( intersperse, sort )
import qualified Data.Map as Map
import           Data.Maybe
import           Text.XHtml hiding     ( name, title, p, quote )

import GHC
import GHC.Exts
import Name
import BooleanFormula

ppDecl :: Bool -> LinksInfo -> LHsDecl DocName
       -> DocForDecl DocName -> [DocInstance DocName] -> [(DocName, Fixity)]
       -> [(DocName, DocForDecl DocName)] -> Splice -> Unicode -> Qualification -> Html
ppDecl summ links (L loc decl) (mbDoc, fnArgsDoc) instances fixities subdocs splice unicode qual = case decl of
  TyClD (FamDecl d)         -> ppTyFam summ False links instances fixities loc mbDoc d splice unicode qual
  TyClD d@(DataDecl {})     -> ppDataDecl summ links instances fixities subdocs loc mbDoc d splice unicode qual
  TyClD d@(SynDecl {})      -> ppTySyn summ links fixities loc (mbDoc, fnArgsDoc) d splice unicode qual
  TyClD d@(ClassDecl {})    -> ppClassDecl summ links instances fixities loc mbDoc subdocs d splice unicode qual
  SigD (TypeSig lnames lty) -> ppLFunSig summ links loc (mbDoc, fnArgsDoc) lnames lty fixities splice unicode qual
  SigD (PatSynSig lname qtvs prov req ty) ->
      ppLPatSig summ links loc (mbDoc, fnArgsDoc) lname qtvs prov req ty fixities splice unicode qual
  ForD d                         -> ppFor summ links loc (mbDoc, fnArgsDoc) d fixities splice unicode qual
  InstD _                        -> noHtml
  _                              -> error "declaration not supported by ppDecl"


ppLFunSig :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName ->
             [Located DocName] -> LHsType DocName -> [(DocName, Fixity)] ->
             Splice -> Unicode -> Qualification -> Html
ppLFunSig summary links loc doc lnames lty fixities splice unicode qual =
  ppFunSig summary links loc doc (map unLoc lnames) (unLoc lty) fixities
           splice unicode qual

ppFunSig :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName ->
            [DocName] -> HsType DocName -> [(DocName, Fixity)] ->
            Splice -> Unicode -> Qualification -> Html
ppFunSig summary links loc doc docnames typ fixities splice unicode qual =
  ppSigLike summary links loc mempty doc docnames fixities (typ, pp_typ)
            splice unicode qual
  where
    pp_typ = ppType unicode qual typ

ppLPatSig :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName ->
             Located DocName ->
             (HsExplicitFlag, LHsTyVarBndrs DocName) ->
             LHsContext DocName -> LHsContext DocName ->
             LHsType DocName ->
             [(DocName, Fixity)] ->
             Splice -> Unicode -> Qualification -> Html
ppLPatSig summary links loc (doc, _argDocs) (L _ name) (expl, qtvs) lprov lreq typ fixities splice unicode qual
  | summary = pref1
  | otherwise = topDeclElem links loc splice [name] (pref1 <+> ppFixities fixities qual)
                +++ docSection Nothing qual doc
  where
    pref1 = hsep [ toHtml "pattern"
                 , ppBinder summary occname
                 , dcolon unicode
                 , ppLTyVarBndrs expl qtvs unicode qual
                 , cxt
                 , ppLType unicode qual typ
                 ]

    cxt = case (ppLContextMaybe lprov unicode qual, ppLContextMaybe lreq unicode qual) of
        (Nothing,   Nothing)  -> noHtml
        (Nothing,   Just req) -> parens noHtml <+> darr <+> req <+> darr
        (Just prov, Nothing)  -> prov <+> darr
        (Just prov, Just req) -> prov <+> darr <+> req <+> darr

    darr = darrow unicode
    occname = nameOccName . getName $ name

ppSigLike :: Bool -> LinksInfo -> SrcSpan -> Html -> DocForDecl DocName ->
             [DocName] -> [(DocName, Fixity)] -> (HsType DocName, Html) ->
             Splice -> Unicode -> Qualification -> Html
ppSigLike summary links loc leader doc docnames fixities (typ, pp_typ)
          splice unicode qual =
  ppTypeOrFunSig summary links loc docnames typ doc
    ( addFixities $ leader <+> ppTypeSig summary occnames pp_typ unicode
    , addFixities . concatHtml . punctuate comma $ map (ppBinder False) occnames
    , dcolon unicode
    )
    splice unicode qual
  where
    occnames = map (nameOccName . getName) docnames
    addFixities html
      | summary   = html
      | otherwise = html <+> ppFixities fixities qual


ppTypeOrFunSig :: Bool -> LinksInfo -> SrcSpan -> [DocName] -> HsType DocName
               -> DocForDecl DocName -> (Html, Html, Html)
               -> Splice -> Unicode -> Qualification -> Html
ppTypeOrFunSig summary links loc docnames typ (doc, argDocs) (pref1, pref2, sep) splice unicode qual
  | summary = pref1
  | Map.null argDocs = topDeclElem links loc splice docnames pref1 +++ docSection curName qual doc
  | otherwise = topDeclElem links loc splice docnames pref2 +++
      subArguments qual (do_args 0 sep typ) +++ docSection curName qual doc
  where
    curName = getName <$> listToMaybe docnames
    argDoc n = Map.lookup n argDocs

    do_largs n leader (L _ t) = do_args n leader t
    do_args :: Int -> Html -> HsType DocName -> [SubDecl]
    do_args n leader (HsForAllTy _ tvs lctxt ltype)
      = case unLoc lctxt of
        [] -> do_largs n leader' ltype
        _  -> (leader' <+> ppLContextNoArrow lctxt unicode qual, Nothing, [])
              : do_largs n (darrow unicode) ltype
      where leader' = leader <+> ppForAll tvs unicode qual
    do_args n leader (HsFunTy lt r)
      = (leader <+> ppLFunLhType unicode qual lt, argDoc n, [])
        : do_largs (n+1) (arrow unicode) r
    do_args n leader t
      = [(leader <+> ppType unicode qual t, argDoc n, [])]

ppForAll :: LHsTyVarBndrs DocName -> Unicode -> Qualification -> Html
ppForAll tvs unicode qual =
  case [ppKTv n k | L _ (KindedTyVar n k) <- hsQTvBndrs tvs] of
    [] -> noHtml
    ts -> forallSymbol unicode <+> hsep ts +++ dot
  where ppKTv n k = parens $
          ppTyName (getName n) <+> dcolon unicode <+> ppLKind unicode qual k

ppFixities :: [(DocName, Fixity)] -> Qualification -> Html
ppFixities [] _ = noHtml
ppFixities fs qual = foldr1 (+++) (map ppFix uniq_fs) +++ rightEdge
  where
    ppFix (ns, p, d) = thespan ! [theclass "fixity"] <<
                         (toHtml d <+> toHtml (show p) <+> ppNames ns)

    ppDir InfixR = "infixr"
    ppDir InfixL = "infixl"
    ppDir InfixN = "infix"

    ppNames = case fs of
      _:[] -> const noHtml -- Don't display names for fixities on single names
      _    -> concatHtml . intersperse (stringToHtml ", ") . map (ppDocName qual Infix False)

    uniq_fs = [ (n, the p, the d') | (n, Fixity p d) <- fs
                                   , let d' = ppDir d
                                   , then group by Down (p,d') using groupWith ]

    rightEdge = thespan ! [theclass "rightedge"] << noHtml


ppTyVars :: LHsTyVarBndrs DocName -> [Html]
ppTyVars tvs = map ppTyName (tyvarNames tvs)


tyvarNames :: LHsTyVarBndrs DocName -> [Name]
tyvarNames = map getName . hsLTyVarNames


ppFor :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName
      -> ForeignDecl DocName -> [(DocName, Fixity)]
      -> Splice -> Unicode -> Qualification -> Html
ppFor summary links loc doc (ForeignImport (L _ name) (L _ typ) _ _) fixities
      splice unicode qual
  = ppFunSig summary links loc doc [name] typ fixities splice unicode qual
ppFor _ _ _ _ _ _ _ _ _ = error "ppFor"


-- we skip type patterns for now
ppTySyn :: Bool -> LinksInfo -> [(DocName, Fixity)] -> SrcSpan
        -> DocForDecl DocName -> TyClDecl DocName
        -> Splice -> Unicode -> Qualification -> Html
ppTySyn summary links fixities loc doc (SynDecl { tcdLName = L _ name, tcdTyVars = ltyvars
                                                , tcdRhs = ltype })
        splice unicode qual
  = ppTypeOrFunSig summary links loc [name] (unLoc ltype) doc
                   (full <+> fixs, hdr <+> fixs, spaceHtml +++ equals)
                   splice unicode qual
  where
    hdr  = hsep ([keyword "type", ppBinder summary occ] ++ ppTyVars ltyvars)
    full = hdr <+> equals <+> ppLType unicode qual ltype
    occ  = nameOccName . getName $ name
    fixs
      | summary   = noHtml
      | otherwise = ppFixities fixities qual
ppTySyn _ _ _ _ _ _ _ _ _ = error "declaration not supported by ppTySyn"


ppTypeSig :: Bool -> [OccName] -> Html  -> Bool -> Html
ppTypeSig summary nms pp_ty unicode =
  concatHtml htmlNames <+> dcolon unicode <+> pp_ty
  where
    htmlNames = intersperse (stringToHtml ", ") $ map (ppBinder summary) nms


ppTyName :: Name -> Html
ppTyName = ppName Prefix


--------------------------------------------------------------------------------
-- * Type families
--------------------------------------------------------------------------------


ppTyFamHeader :: Bool -> Bool -> FamilyDecl DocName
              -> Unicode -> Qualification -> Html
ppTyFamHeader summary associated d@(FamilyDecl { fdInfo = info
                                               , fdKindSig = mkind })
              unicode qual =
  (case info of
     OpenTypeFamily
       | associated -> keyword "type"
       | otherwise  -> keyword "type family"
     DataFamily
       | associated -> keyword "data"
       | otherwise  -> keyword "data family"
     ClosedTypeFamily _
                    -> keyword "type family"
  ) <+>

  ppFamDeclBinderWithVars summary d <+>

  (case mkind of
    Just kind -> dcolon unicode  <+> ppLKind unicode qual kind
    Nothing   -> noHtml
  )

ppTyFam :: Bool -> Bool -> LinksInfo -> [DocInstance DocName] ->
           [(DocName, Fixity)] -> SrcSpan -> Documentation DocName ->
           FamilyDecl DocName -> Splice -> Unicode -> Qualification -> Html
ppTyFam summary associated links instances fixities loc doc decl splice unicode qual

  | summary   = ppTyFamHeader True associated decl unicode qual
  | otherwise = header_ +++ docSection Nothing qual doc +++ instancesBit

  where
    docname = unLoc $ fdLName decl

    header_ = topDeclElem links loc splice [docname] $
       ppTyFamHeader summary associated decl unicode qual <+> ppFixities fixities qual

    instancesBit
      | FamilyDecl { fdInfo = ClosedTypeFamily eqns } <- decl
      , not summary
      = subEquations qual $ map (ppTyFamEqn . unLoc) eqns

      | otherwise
      = ppInstances instances docname unicode qual

    -- Individual equation of a closed type family
    ppTyFamEqn TyFamEqn { tfe_tycon = n, tfe_rhs = rhs
                        , tfe_pats = HsWB { hswb_cts = ts }}
      = ( ppAppNameTypes (unLoc n) [] (map unLoc ts) unicode qual
          <+> equals <+> ppType unicode qual (unLoc rhs)
        , Nothing, [] )

--------------------------------------------------------------------------------
-- * Associated Types
--------------------------------------------------------------------------------


ppAssocType :: Bool -> LinksInfo -> DocForDecl DocName -> LFamilyDecl DocName
            -> [(DocName, Fixity)] -> Splice -> Unicode -> Qualification -> Html
ppAssocType summ links doc (L loc decl) fixities splice unicode qual =
   ppTyFam summ True links [] fixities loc (fst doc) decl splice unicode qual


--------------------------------------------------------------------------------
-- * TyClDecl helpers
--------------------------------------------------------------------------------

-- | Print a type family and its variables
ppFamDeclBinderWithVars :: Bool -> FamilyDecl DocName -> Html
ppFamDeclBinderWithVars summ (FamilyDecl { fdLName = lname, fdTyVars = tvs }) =
  ppAppDocNameNames summ (unLoc lname) (tyvarNames tvs)

-- | Print a newtype / data binder and its variables
ppDataBinderWithVars :: Bool -> TyClDecl DocName -> Html
ppDataBinderWithVars summ decl =
  ppAppDocNameNames summ (tcdName decl) (tyvarNames $ tcdTyVars decl)

--------------------------------------------------------------------------------
-- * Type applications
--------------------------------------------------------------------------------


-- | Print an application of a DocName and two lists of HsTypes (kinds, types)
ppAppNameTypes :: DocName -> [HsType DocName] -> [HsType DocName]
               -> Unicode -> Qualification -> Html
ppAppNameTypes n ks ts unicode qual =
    ppTypeApp n ks ts (\p -> ppDocName qual p True) (ppParendType unicode qual)


-- | Print an application of a DocName and a list of Names
ppAppDocNameNames :: Bool -> DocName -> [Name] -> Html
ppAppDocNameNames summ n ns =
    ppTypeApp n [] ns ppDN ppTyName
  where
    ppDN notation = ppBinderFixity notation summ . nameOccName . getName
    ppBinderFixity Infix = ppBinderInfix
    ppBinderFixity _ = ppBinder

-- | General printing of type applications
ppTypeApp :: DocName -> [a] -> [a] -> (Notation -> DocName -> Html) -> (a -> Html) -> Html
ppTypeApp n [] (t1:t2:rest) ppDN ppT
  | operator, not . null $ rest = parens opApp <+> hsep (map ppT rest)
  | operator                    = opApp
  where
    operator = isNameSym . getName $ n
    opApp = ppT t1 <+> ppDN Infix n <+> ppT t2

ppTypeApp n ks ts ppDN ppT = ppDN Prefix n <+> hsep (map ppT $ ks ++ ts)


-------------------------------------------------------------------------------
-- * Contexts
-------------------------------------------------------------------------------


ppLContext, ppLContextNoArrow :: Located (HsContext DocName) -> Unicode
                              -> Qualification -> Html
ppLContext        = ppContext        . unLoc
ppLContextNoArrow = ppContextNoArrow . unLoc


ppLContextMaybe :: Located (HsContext DocName) -> Unicode -> Qualification -> Maybe Html
ppLContextMaybe = ppContextNoLocsMaybe . map unLoc . unLoc

ppContextNoArrow :: HsContext DocName -> Unicode -> Qualification -> Html
ppContextNoArrow cxt unicode qual = fromMaybe noHtml $
                                    ppContextNoLocsMaybe (map unLoc cxt) unicode qual


ppContextNoLocs :: [HsType DocName] -> Unicode -> Qualification -> Html
ppContextNoLocs cxt unicode qual = maybe noHtml (<+> darrow unicode) $
                                   ppContextNoLocsMaybe cxt unicode qual


ppContextNoLocsMaybe :: [HsType DocName] -> Unicode -> Qualification -> Maybe Html
ppContextNoLocsMaybe []  _       _    = Nothing
ppContextNoLocsMaybe cxt unicode qual = Just $ ppHsContext cxt unicode qual

ppContext :: HsContext DocName -> Unicode -> Qualification -> Html
ppContext cxt unicode qual = ppContextNoLocs (map unLoc cxt) unicode qual


ppHsContext :: [HsType DocName] -> Unicode -> Qualification-> Html
ppHsContext []  _       _     = noHtml
ppHsContext [p] unicode qual = ppCtxType unicode qual p
ppHsContext cxt unicode qual = parenList (map (ppType unicode qual) cxt)


-------------------------------------------------------------------------------
-- * Class declarations
-------------------------------------------------------------------------------


ppClassHdr :: Bool -> Located [LHsType DocName] -> DocName
           -> LHsTyVarBndrs DocName -> [Located ([DocName], [DocName])]
           -> Unicode -> Qualification -> Html
ppClassHdr summ lctxt n tvs fds unicode qual =
  keyword "class"
  <+> (if not . null . unLoc $ lctxt then ppLContext lctxt unicode qual else noHtml)
  <+> ppAppDocNameNames summ n (tyvarNames tvs)
  <+> ppFds fds unicode qual


ppFds :: [Located ([DocName], [DocName])] -> Unicode -> Qualification -> Html
ppFds fds unicode qual =
  if null fds then noHtml else
        char '|' <+> hsep (punctuate comma (map (fundep . unLoc) fds))
  where
        fundep (vars1,vars2) = ppVars vars1 <+> arrow unicode <+> ppVars vars2
        ppVars = hsep . map (ppDocName qual Prefix True)

ppShortClassDecl :: Bool -> LinksInfo -> TyClDecl DocName -> SrcSpan
                 -> [(DocName, DocForDecl DocName)]
                 -> Splice -> Unicode -> Qualification -> Html
ppShortClassDecl summary links (ClassDecl { tcdCtxt = lctxt, tcdLName = lname, tcdTyVars = tvs
                                          , tcdFDs = fds, tcdSigs = sigs, tcdATs = ats }) loc
    subdocs splice unicode qual =
  if not (any isVanillaLSig sigs) && null ats
    then (if summary then id else topDeclElem links loc splice [nm]) hdr
    else (if summary then id else topDeclElem links loc splice [nm]) (hdr <+> keyword "where")
      +++ shortSubDecls False
          (
            [ ppAssocType summary links doc at [] splice unicode qual | at <- ats
              , let doc = lookupAnySubdoc (unL $ fdLName $ unL at) subdocs ]  ++

                -- ToDo: add associated type defaults

            [ ppFunSig summary links loc doc names typ [] splice unicode qual
              | L _ (TypeSig lnames (L _ typ)) <- sigs
              , let doc = lookupAnySubdoc (head names) subdocs
                    names = map unLoc lnames ]
              -- FIXME: is taking just the first name ok? Is it possible that
              -- there are different subdocs for different names in a single
              -- type signature?
          )
  where
    hdr = ppClassHdr summary lctxt (unLoc lname) tvs fds unicode qual
    nm  = unLoc lname
ppShortClassDecl _ _ _ _ _ _ _ _ = error "declaration type not supported by ppShortClassDecl"



ppClassDecl :: Bool -> LinksInfo -> [DocInstance DocName] -> [(DocName, Fixity)]
            -> SrcSpan -> Documentation DocName
            -> [(DocName, DocForDecl DocName)] -> TyClDecl DocName
            -> Splice -> Unicode -> Qualification -> Html
ppClassDecl summary links instances fixities loc d subdocs
        decl@(ClassDecl { tcdCtxt = lctxt, tcdLName = lname, tcdTyVars = ltyvars
                        , tcdFDs = lfds, tcdSigs = lsigs, tcdATs = ats })
            splice unicode qual
  | summary = ppShortClassDecl summary links decl loc subdocs splice unicode qual
  | otherwise = classheader +++ docSection Nothing qual d
                  +++ minimalBit +++ atBit +++ methodBit +++ instancesBit
  where
    classheader
      | any isVanillaLSig lsigs = topDeclElem links loc splice [nm] (hdr unicode qual <+> keyword "where" <+> fixs)
      | otherwise = topDeclElem links loc splice [nm] (hdr unicode qual <+> fixs)

    -- Only the fixity relevant to the class header
    fixs = ppFixities [ f | f@(n,_) <- fixities, n == unLoc lname ] qual

    nm   = tcdName decl

    hdr = ppClassHdr summary lctxt (unLoc lname) ltyvars lfds

    -- ToDo: add assocatied typ defaults
    atBit = subAssociatedTypes [ ppAssocType summary links doc at subfixs splice unicode qual
                      | at <- ats
                      , let n = unL . fdLName $ unL at
                            doc = lookupAnySubdoc (unL $ fdLName $ unL at) subdocs
                            subfixs = [ f | f@(n',_) <- fixities, n == n' ] ]

    methodBit = subMethods [ ppFunSig summary links loc doc names typ subfixs splice unicode qual
                           | L _ (TypeSig lnames (L _ typ)) <- lsigs
                           , let doc = lookupAnySubdoc (head names) subdocs
                                 subfixs = [ f | n <- names
                                               , f@(n',_) <- fixities
                                               , n == n' ]
                                 names = map unLoc lnames ]
                           -- FIXME: is taking just the first name ok? Is it possible that
                           -- there are different subdocs for different names in a single
                           -- type signature?

    minimalBit = case [ s | L _ (MinimalSig s) <- lsigs ] of
      -- Miminal complete definition = every shown method
      And xs : _ | sort [getName n | Var (L _ n) <- xs] ==
                   sort [getName n | L _ (TypeSig ns _) <- lsigs, L _ n <- ns]
        -> noHtml

      -- Minimal complete definition = the only shown method
      Var (L _ n) : _ | [getName n] ==
                        [getName n' | L _ (TypeSig ns _) <- lsigs, L _ n' <- ns]
        -> noHtml

      -- Minimal complete definition = nothing
      And [] : _ -> subMinimal $ toHtml "Nothing"

      m : _  -> subMinimal $ ppMinimal False m
      _ -> noHtml

    ppMinimal _ (Var (L _ n)) = ppDocName qual Prefix True n
    ppMinimal _ (And fs) = foldr1 (\a b -> a+++", "+++b) $ map (ppMinimal True) fs
    ppMinimal p (Or fs) = wrap $ foldr1 (\a b -> a+++" | "+++b) $ map (ppMinimal False) fs
      where wrap | p = parens | otherwise = id

    instancesBit = ppInstances instances nm unicode qual

ppClassDecl _ _ _ _ _ _ _ _ _ _ _ = error "declaration type not supported by ppShortClassDecl"


ppInstances :: [DocInstance DocName] -> DocName -> Unicode -> Qualification -> Html
ppInstances instances baseName unicode qual
  = subInstances qual instName (map instDecl instances)
  where
    instName = getOccString $ getName baseName
    instDecl :: DocInstance DocName -> SubDecl
    instDecl (inst, maybeDoc) = (instHead inst, maybeDoc, [])
    instHead (n, ks, ts, ClassInst cs) = ppContextNoLocs cs unicode qual
        <+> ppAppNameTypes n ks ts unicode qual
    instHead (n, ks, ts, TypeInst rhs) = keyword "type"
        <+> ppAppNameTypes n ks ts unicode qual
        <+> maybe noHtml (\t -> equals <+> ppType unicode qual t) rhs
    instHead (n, ks, ts, DataInst dd) = keyword "data"
        <+> ppAppNameTypes n ks ts unicode qual
        <+> ppShortDataDecl False True dd unicode qual

lookupAnySubdoc :: Eq id1 => id1 -> [(id1, DocForDecl id2)] -> DocForDecl id2
lookupAnySubdoc n = fromMaybe noDocForDecl . lookup n


-------------------------------------------------------------------------------
-- * Data & newtype declarations
-------------------------------------------------------------------------------


-- TODO: print contexts
ppShortDataDecl :: Bool -> Bool -> TyClDecl DocName -> Unicode -> Qualification -> Html
ppShortDataDecl summary dataInst dataDecl unicode qual

  | [] <- cons = dataHeader

  | [lcon] <- cons, ResTyH98 <- resTy,
    (cHead,cBody,cFoot) <- ppShortConstrParts summary dataInst (unLoc lcon) unicode qual
       = (dataHeader <+> equals <+> cHead) +++ cBody +++ cFoot

  | ResTyH98 <- resTy = dataHeader
      +++ shortSubDecls dataInst (zipWith doConstr ('=':repeat '|') cons)

  | otherwise = (dataHeader <+> keyword "where")
      +++ shortSubDecls dataInst (map doGADTConstr cons)

  where
    dataHeader
      | dataInst  = noHtml
      | otherwise = ppDataHeader summary dataDecl unicode qual
    doConstr c con = toHtml [c] <+> ppShortConstr summary (unLoc con) unicode qual
    doGADTConstr con = ppShortConstr summary (unLoc con) unicode qual

    cons      = dd_cons (tcdDataDefn dataDecl)
    resTy     = (con_res . unLoc . head) cons


ppDataDecl :: Bool -> LinksInfo -> [DocInstance DocName] -> [(DocName, Fixity)] ->
              [(DocName, DocForDecl DocName)] ->
              SrcSpan -> Documentation DocName -> TyClDecl DocName ->
              Splice -> Unicode -> Qualification -> Html
ppDataDecl summary links instances fixities subdocs loc doc dataDecl
           splice unicode qual

  | summary   = ppShortDataDecl summary False dataDecl unicode qual
  | otherwise = header_ +++ docSection Nothing qual doc +++ constrBit +++ instancesBit

  where
    docname   = tcdName dataDecl
    cons      = dd_cons (tcdDataDefn dataDecl)
    resTy     = (con_res . unLoc . head) cons

    header_ = topDeclElem links loc splice [docname] $
             ppDataHeader summary dataDecl unicode qual <+> whereBit <+> fix

    fix = ppFixities (filter (\(n,_) -> n == docname) fixities) qual

    whereBit
      | null cons = noHtml
      | otherwise = case resTy of
        ResTyGADT _ -> keyword "where"
        _ -> noHtml

    constrBit = subConstructors qual
      [ ppSideBySideConstr subdocs subfixs unicode qual c
      | c <- cons
      , let subfixs = filter (\(n,_) -> any (\cn -> cn == n)
                                     (map unLoc (con_names (unLoc c)))) fixities
      ]

    instancesBit = ppInstances instances docname unicode qual



ppShortConstr :: Bool -> ConDecl DocName -> Unicode -> Qualification -> Html
ppShortConstr summary con unicode qual = cHead <+> cBody <+> cFoot
  where
    (cHead,cBody,cFoot) = ppShortConstrParts summary False con unicode qual


-- returns three pieces: header, body, footer so that header & footer can be
-- incorporated into the declaration
ppShortConstrParts :: Bool -> Bool -> ConDecl DocName -> Unicode -> Qualification -> (Html, Html, Html)
ppShortConstrParts summary dataInst con unicode qual = case con_res con of
  ResTyH98 -> case con_details con of
    PrefixCon args ->
      (header_ unicode qual +++ hsep (ppOcc
            : map (ppLParendType unicode qual) args), noHtml, noHtml)
    RecCon fields ->
      (header_ unicode qual +++ ppOcc <+> char '{',
       doRecordFields fields,
       char '}')
    InfixCon arg1 arg2 ->
      (header_ unicode qual +++ hsep [ppLParendType unicode qual arg1,
            ppOccInfix, ppLParendType unicode qual arg2],
       noHtml, noHtml)

  ResTyGADT resTy -> case con_details con of
    -- prefix & infix could use hsConDeclArgTys if it seemed to
    -- simplify the code.
    PrefixCon args -> (doGADTCon args resTy, noHtml, noHtml)
    -- display GADT records with the new syntax,
    -- Constr :: (Context) => { field :: a, field2 :: b } -> Ty (a, b)
    -- (except each field gets its own line in docs, to match
    -- non-GADT records)
    RecCon fields -> (ppOcc <+> dcolon unicode <+>
                            ppForAllCon forall_ ltvs lcontext unicode qual <+> char '{',
                            doRecordFields fields,
                            char '}' <+> arrow unicode <+> ppLType unicode qual resTy)
    InfixCon arg1 arg2 -> (doGADTCon [arg1, arg2] resTy, noHtml, noHtml)

  where
    doRecordFields fields = shortSubDecls dataInst (map (ppShortField summary unicode qual) (map unLoc fields))
    doGADTCon args resTy = ppOcc <+> dcolon unicode <+> hsep [
                             ppForAllCon forall_ ltvs lcontext unicode qual,
                             ppLType unicode qual (foldr mkFunTy resTy args) ]

    header_  = ppConstrHdr forall_ tyVars context
    occ        = map (nameOccName . getName . unLoc) $ con_names con

    ppOcc      = case occ of
      [one] -> ppBinder summary one
      _     -> hsep (punctuate comma (map (ppBinder summary) occ))

    ppOccInfix = case occ of
      [one] -> ppBinderInfix summary one
      _     -> hsep (punctuate comma (map (ppBinderInfix summary) occ))

    ltvs     = con_qvars con
    tyVars   = tyvarNames ltvs
    lcontext = con_cxt con
    context  = unLoc (con_cxt con)
    forall_  = con_explicit con
    mkFunTy a b = noLoc (HsFunTy a b)


-- ppConstrHdr is for (non-GADT) existentials constructors' syntax
ppConstrHdr :: HsExplicitFlag -> [Name] -> HsContext DocName -> Unicode
            -> Qualification -> Html
ppConstrHdr forall_ tvs ctxt unicode qual
 = (if null tvs then noHtml else ppForall)
   +++
   (if null ctxt then noHtml else ppContextNoArrow ctxt unicode qual
        <+> darrow unicode +++ toHtml " ")
  where
    ppForall = case forall_ of
      Explicit -> forallSymbol unicode <+> hsep (map (ppName Prefix) tvs) <+> toHtml ". "
      Qualified -> noHtml
      Implicit -> noHtml


ppSideBySideConstr :: [(DocName, DocForDecl DocName)] -> [(DocName, Fixity)]
                   -> Unicode -> Qualification -> LConDecl DocName -> SubDecl
ppSideBySideConstr subdocs fixities unicode qual (L _ con) = (decl, mbDoc, fieldPart)
 where
    decl = case con_res con of
      ResTyH98 -> case con_details con of
        PrefixCon args ->
          hsep ((header_ +++ ppOcc)
            : map (ppLParendType unicode qual) args)
          <+> fixity

        RecCon _ -> header_ +++ ppOcc <+> fixity

        InfixCon arg1 arg2 ->
          hsep [header_ +++ ppLParendType unicode qual arg1,
            ppOccInfix,
            ppLParendType unicode qual arg2]
          <+> fixity

      ResTyGADT resTy -> case con_details con of
        -- prefix & infix could also use hsConDeclArgTys if it seemed to
        -- simplify the code.
        PrefixCon args -> doGADTCon args resTy
        cd@(RecCon _) -> doGADTCon (hsConDeclArgTys cd) resTy
        InfixCon arg1 arg2 -> doGADTCon [arg1, arg2] resTy

    fieldPart = case con_details con of
        RecCon fields -> [doRecordFields fields]
        _ -> []

    doRecordFields fields = subFields qual
      (map (ppSideBySideField subdocs unicode qual) (map unLoc fields))
    doGADTCon :: [LHsType DocName] -> Located (HsType DocName) -> Html
    doGADTCon args resTy = ppOcc <+> dcolon unicode
        <+> hsep [ppForAllCon forall_ ltvs (con_cxt con) unicode qual,
                  ppLType unicode qual (foldr mkFunTy resTy args) ]
        <+> fixity

    fixity  = ppFixities fixities qual
    header_ = ppConstrHdr forall_ tyVars context unicode qual
    occ       = map (nameOccName . getName . unLoc) $ con_names con

    ppOcc     = case occ of
      [one] -> ppBinder False one
      _     -> hsep (punctuate comma (map (ppBinder False) occ))

    ppOccInfix = case occ of
      [one] -> ppBinderInfix False one
      _     -> hsep (punctuate comma (map (ppBinderInfix False) occ))

    ltvs    = con_qvars con
    tyVars  = tyvarNames (con_qvars con)
    context = unLoc (con_cxt con)
    forall_ = con_explicit con
    -- don't use "con_doc con", in case it's reconstructed from a .hi file,
    -- or also because we want Haddock to do the doc-parsing, not GHC.
    mbDoc = lookup (unLoc $ head $ con_names con) subdocs >>=
            combineDocumentation . fst
    mkFunTy a b = noLoc (HsFunTy a b)


ppSideBySideField :: [(DocName, DocForDecl DocName)] -> Unicode -> Qualification
                  -> ConDeclField DocName -> SubDecl
ppSideBySideField subdocs unicode qual (ConDeclField names ltype _) =
  (hsep (punctuate comma (map ((ppBinder False) . nameOccName . getName . unL) names)) <+> dcolon unicode <+> ppLType unicode qual ltype,
    mbDoc,
    [])
  where
    -- don't use cd_fld_doc for same reason we don't use con_doc above
    -- Where there is more than one name, they all have the same documentation
    mbDoc = lookup (unL $ head names) subdocs >>= combineDocumentation . fst


ppShortField :: Bool -> Unicode -> Qualification -> ConDeclField DocName -> Html
ppShortField summary unicode qual (ConDeclField names ltype _)
  = hsep (punctuate comma (map ((ppBinder summary) . nameOccName . getName . unL) names))
    <+> dcolon unicode <+> ppLType unicode qual ltype


-- | Print the LHS of a data\/newtype declaration.
-- Currently doesn't handle 'data instance' decls or kind signatures
ppDataHeader :: Bool -> TyClDecl DocName -> Unicode -> Qualification -> Html
ppDataHeader summary decl@(DataDecl { tcdDataDefn =
                                         HsDataDefn { dd_ND = nd
                                                    , dd_ctxt = ctxt
                                                    , dd_kindSig = ks } })
             unicode qual
  = -- newtype or data
    (case nd of { NewType -> keyword "newtype"; DataType -> keyword "data" })
    <+>
    -- context
    ppLContext ctxt unicode qual <+>
    -- T a b c ..., or a :+: b
    ppDataBinderWithVars summary decl
    <+> case ks of
      Nothing -> mempty
      Just (L _ x) -> dcolon unicode <+> ppKind unicode qual x

ppDataHeader _ _ _ _ = error "ppDataHeader: illegal argument"

--------------------------------------------------------------------------------
-- * Types and contexts
--------------------------------------------------------------------------------


ppBang :: HsBang -> Html
ppBang HsNoBang = noHtml
ppBang _        = toHtml "!" -- Unpacked args is an implementation detail,
                             -- so we just show the strictness annotation


tupleParens :: HsTupleSort -> [Html] -> Html
tupleParens HsUnboxedTuple = ubxParenList
tupleParens _              = parenList


--------------------------------------------------------------------------------
-- * Rendering of HsType
--------------------------------------------------------------------------------


pREC_TOP, pREC_CTX, pREC_FUN, pREC_OP, pREC_CON :: Int

pREC_TOP = 0 :: Int   -- type in ParseIface.y in GHC
pREC_CTX = 1 :: Int   -- Used for single contexts, eg. ctx => type
                      -- (as opposed to (ctx1, ctx2) => type)
pREC_FUN = 2 :: Int   -- btype in ParseIface.y in GHC
                      -- Used for LH arg of (->)
pREC_OP  = 3 :: Int   -- Used for arg of any infix operator
                      -- (we don't keep their fixities around)
pREC_CON = 4 :: Int   -- Used for arg of type applicn:
                      -- always parenthesise unless atomic

maybeParen :: Int           -- Precedence of context
           -> Int           -- Precedence of top-level operator
           -> Html -> Html  -- Wrap in parens if (ctxt >= op)
maybeParen ctxt_prec op_prec p | ctxt_prec >= op_prec = parens p
                               | otherwise            = p


ppLType, ppLParendType, ppLFunLhType :: Unicode -> Qualification
                                     -> Located (HsType DocName) -> Html
ppLType       unicode qual y = ppType unicode qual (unLoc y)
ppLParendType unicode qual y = ppParendType unicode qual (unLoc y)
ppLFunLhType  unicode qual y = ppFunLhType unicode qual (unLoc y)


ppType, ppCtxType, ppParendType, ppFunLhType :: Unicode -> Qualification
                                             -> HsType DocName -> Html
ppType       unicode qual ty = ppr_mono_ty pREC_TOP ty unicode qual
ppCtxType    unicode qual ty = ppr_mono_ty pREC_CTX ty unicode qual
ppParendType unicode qual ty = ppr_mono_ty pREC_CON ty unicode qual
ppFunLhType  unicode qual ty = ppr_mono_ty pREC_FUN ty unicode qual

ppLKind :: Unicode -> Qualification -> LHsKind DocName -> Html
ppLKind unicode qual y = ppKind unicode qual (unLoc y)

ppKind :: Unicode -> Qualification -> HsKind DocName -> Html
ppKind unicode qual ki = ppr_mono_ty pREC_TOP ki unicode qual

-- Drop top-level for-all type variables in user style
-- since they are implicit in Haskell

ppForAllCon :: HsExplicitFlag -> LHsTyVarBndrs DocName
         -> Located (HsContext DocName) -> Unicode -> Qualification -> Html
ppForAllCon expl tvs cxt unicode qual
  | show_forall = forall_part <+> ppLContext cxt unicode qual
  | otherwise   = ppLContext cxt unicode qual
  where
    forall_part = ppLTyVarBndrs expl tvs unicode qual

ppLTyVarBndrs :: HsExplicitFlag -> LHsTyVarBndrs DocName
              -> Unicode -> Qualification
              -> Html
ppLTyVarBndrs expl tvs unicode _qual
  | show_forall = hsep (forallSymbol unicode : ppTyVars tvs) +++ dot
  | otherwise   = noHtml
  where
    show_forall = not (null (hsQTvBndrs tvs)) && is_explicit
    is_explicit = case expl of {Explicit -> True; Implicit -> False; Qualified -> False}


ppr_mono_lty :: Int -> LHsType DocName -> Unicode -> Qualification -> Html
ppr_mono_lty ctxt_prec ty = ppr_mono_ty ctxt_prec (unLoc ty)


ppr_mono_ty :: Int -> HsType DocName -> Unicode -> Qualification -> Html
ppr_mono_ty ctxt_prec (HsForAllTy expl tvs ctxt ty) unicode qual
  = maybeParen ctxt_prec pREC_FUN $ ppForAllCon expl tvs ctxt unicode qual
                                    <+> ppr_mono_lty pREC_TOP ty unicode qual

-- UnicodeSyntax alternatives
ppr_mono_ty _ (HsTyVar name) True _
  | getOccString (getName name) == "*"    = toHtml "★"
  | getOccString (getName name) == "(->)" = toHtml "(→)"

ppr_mono_ty _         (HsBangTy b ty)     u q = ppBang b +++ ppLParendType u q ty
ppr_mono_ty _         (HsTyVar name)      _ q = ppDocName q Prefix True name
ppr_mono_ty ctxt_prec (HsFunTy ty1 ty2)   u q = ppr_fun_ty ctxt_prec ty1 ty2 u q
ppr_mono_ty _         (HsTupleTy con tys) u q = tupleParens con (map (ppLType u q) tys)
ppr_mono_ty _         (HsKindSig ty kind) u q =
    parens (ppr_mono_lty pREC_TOP ty u q <+> dcolon u <+> ppLKind u q kind)
ppr_mono_ty _         (HsListTy ty)       u q = brackets (ppr_mono_lty pREC_TOP ty u q)
ppr_mono_ty _         (HsPArrTy ty)       u q = pabrackets (ppr_mono_lty pREC_TOP ty u q)
ppr_mono_ty ctxt_prec (HsIParamTy n ty)   u q =
    maybeParen ctxt_prec pREC_CTX $ ppIPName n <+> dcolon u <+> ppr_mono_lty pREC_TOP ty u q
ppr_mono_ty _         (HsSpliceTy {})     _ _ = error "ppr_mono_ty HsSpliceTy"
ppr_mono_ty _         (HsQuasiQuoteTy {}) _ _ = error "ppr_mono_ty HsQuasiQuoteTy"
ppr_mono_ty _         (HsRecTy {})        _ _ = error "ppr_mono_ty HsRecTy"
ppr_mono_ty _         (HsCoreTy {})       _ _ = error "ppr_mono_ty HsCoreTy"
ppr_mono_ty _         (HsExplicitListTy _ tys) u q = quote $ brackets $ hsep $ punctuate comma $ map (ppLType u q) tys
ppr_mono_ty _         (HsExplicitTupleTy _ tys) u q = quote $ parenList $ map (ppLType u q) tys
ppr_mono_ty _         (HsWrapTy {})       _ _ = error "ppr_mono_ty HsWrapTy"

ppr_mono_ty ctxt_prec (HsEqTy ty1 ty2) unicode qual
  = maybeParen ctxt_prec pREC_CTX $
    ppr_mono_lty pREC_OP ty1 unicode qual <+> char '~' <+> ppr_mono_lty pREC_OP ty2 unicode qual

ppr_mono_ty ctxt_prec (HsAppTy fun_ty arg_ty) unicode qual
  = maybeParen ctxt_prec pREC_CON $
    hsep [ppr_mono_lty pREC_FUN fun_ty unicode qual, ppr_mono_lty pREC_CON arg_ty unicode qual]

ppr_mono_ty ctxt_prec (HsOpTy ty1 (_, op) ty2) unicode qual
  = maybeParen ctxt_prec pREC_FUN $
    ppr_mono_lty pREC_OP ty1 unicode qual <+> ppr_op <+> ppr_mono_lty pREC_OP ty2 unicode qual
  where
    ppr_op = ppLDocName qual Infix op

ppr_mono_ty ctxt_prec (HsParTy ty) unicode qual
--  = parens (ppr_mono_lty pREC_TOP ty)
  = ppr_mono_lty ctxt_prec ty unicode qual

ppr_mono_ty ctxt_prec (HsDocTy ty _) unicode qual
  = ppr_mono_lty ctxt_prec ty unicode qual

ppr_mono_ty _ (HsTyLit n) _ _ = ppr_tylit n

ppr_tylit :: HsTyLit -> Html
ppr_tylit (HsNumTy n) = toHtml (show n)
ppr_tylit (HsStrTy s) = toHtml (show s)


ppr_fun_ty :: Int -> LHsType DocName -> LHsType DocName -> Unicode -> Qualification -> Html
ppr_fun_ty ctxt_prec ty1 ty2 unicode qual
  = let p1 = ppr_mono_lty pREC_FUN ty1 unicode qual
        p2 = ppr_mono_lty pREC_TOP ty2 unicode qual
    in
    maybeParen ctxt_prec pREC_FUN $
    hsep [p1, arrow unicode <+> p2]