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1+{-# LANGUAGE LambdaCase #-}
2+{-# LANGUAGE MultiWayIf #-}
3+{-# LANGUAGE OverloadedStrings #-}
4+{-# LANGUAGE RecordWildCards #-}
5+{-# LANGUAGE TypeApplications #-}
7+module Ormolu.Printer.Meat.Declaration.Value
16+import Bag (bagToList)
19+import Ctype (is_space)
20+import Data.Bool (bool)
21+import Data.Char (isPunctuation, isSymbol)
22+import Data.Data hiding (Infix, Prefix)
23+import Data.Functor ((<&>))
24+import Data.List (intersperse, sortOn)
25+import Data.List.NonEmpty (NonEmpty (..), (<|))
26+import qualified Data.List.NonEmpty as NE
27+import Data.Text (Text)
28+import qualified Data.Text as Text
30+import OccName (occNameString)
31+import Ormolu.Printer.Combinators
32+import Ormolu.Printer.Internal
33+import Ormolu.Printer.Meat.Common
34+import {-# SOURCE #-} Ormolu.Printer.Meat.Declaration
35+import Ormolu.Printer.Meat.Declaration.Signature
36+import Ormolu.Printer.Meat.Type
37+import Ormolu.Printer.Operators
40+-- | Style of a group of equations.
42+ = Function (Located RdrName)
48+-- | Style of equations in a group.
53+-- | Expression placement. This marks the places where expressions that
54+-- implement handing forms may use them.
56+ = -- | Multi-line layout should cause
57+ -- insertion of a newline and indentation
60+ | -- | Expressions that have hanging form
61+ -- should use it and avoid bumping one level
66+p_valDecl :: HsBindLR GhcPs GhcPs -> R ()
68+ FunBind NoExtField funId funMatches _ _ -> p_funBind funId funMatches
69+ PatBind NoExtField pat grhss _ -> p_match PatternBind False NoSrcStrict [pat] grhss
70+ VarBind {} -> notImplemented "VarBinds" -- introduced by the type checker
71+ AbsBinds {} -> notImplemented "AbsBinds" -- introduced by the type checker
72+ PatSynBind NoExtField psb -> p_patSynBind psb
73+ XHsBindsLR x -> noExtCon x
77+ MatchGroup GhcPs (LHsExpr GhcPs) ->
79+p_funBind name = p_matchGroup (Function name)
83+ MatchGroup GhcPs (LHsExpr GhcPs) ->
85+p_matchGroup = p_matchGroup' exprPlacement p_hsExpr
89+ -- | How to get body placement
90+ (body -> Placement) ->
91+ -- | How to print body
93+ -- | Style of this group of equations
96+ MatchGroup GhcPs (Located body) ->
98+p_matchGroup' placer render style MG {..} = do
99+ let ob = case style of
103+ -- Since we are forcing braces on 'sepSemi' based on 'ob', we have to
104+ -- restore the brace state inside the sepsemi.
105+ ub <- bool dontUseBraces useBraces <$> canUseBraces
106+ ob $ sepSemi (located' (ub . p_Match)) (unLoc mg_alts)
108+ p_Match m@Match {..} =
112+ (adjustMatchGroupStyle m style)
117+ p_Match (XMatch x) = noExtCon x
118+p_matchGroup' _ _ _ (XMatchGroup x) = noExtCon x
120+-- | Function id obtained through pattern matching on 'FunBind' should not
121+-- be used to print the actual equations because the different ‘RdrNames’
122+-- used in the equations may have different “decorations” (such as backticks
123+-- and paretheses) associated with them. It is necessary to use per-equation
124+-- names obtained from 'm_ctxt' of 'Match'. This function replaces function
125+-- name inside of 'Function' accordingly.
126+adjustMatchGroupStyle ::
130+adjustMatchGroupStyle m = \case
131+ Function _ -> (Function . mc_fun . m_ctxt) m
134+matchStrictness :: Match id body -> SrcStrictness
135+matchStrictness match =
136+ case m_ctxt match of
137+ FunRhs {mc_strictness = s} -> s
141+ -- | Style of the group
143+ -- | Is this an infix match?
145+ -- | Strictness prefix (FunBind)
147+ -- | Argument patterns
150+ GRHSs GhcPs (LHsExpr GhcPs) ->
152+p_match = p_match' exprPlacement p_hsExpr
156+ -- | How to get body placement
157+ (body -> Placement) ->
158+ -- | How to print body
160+ -- | Style of this group of equations
162+ -- | Is this an infix match?
164+ -- | Strictness prefix (FunBind)
166+ -- | Argument patterns
169+ GRHSs GhcPs (Located body) ->
171+p_match' placer render style isInfix strictness m_pats GRHSs {..} = do
172+ -- Normally, since patterns may be placed in a multi-line layout, it is
173+ -- necessary to bump indentation for the pattern group so it's more
174+ -- indented than function name. This in turn means that indentation for
175+ -- the body should also be bumped. Normally this would mean that bodies
176+ -- would start with two indentation steps applied, which is ugly, so we
177+ -- need to be a bit more clever here and bump indentation level only when
178+ -- pattern group is multiline.
180+ NoSrcStrict -> return ()
181+ SrcStrict -> txt "!"
183+ indentBody <- case NE.nonEmpty m_pats of
185+ False <$ case style of
186+ Function name -> p_rdrName name
189+ let combinedSpans = case style of
190+ Function name -> combineSrcSpans (getLoc name) patSpans
192+ patSpans = combineSrcSpans' (getLoc <$> ne_pats)
193+ indentBody = not (isOneLineSpan combinedSpans)
194+ switchLayout [combinedSpans] $ do
195+ let stdCase = sep breakpoint (located' p_pat) m_pats
202+ (located' p_pat <$> m_pats)
203+ PatternBind -> stdCase
206+ let needsSpace = case unLoc (NE.head ne_pats) of
209+ SplicePat _ _ -> True
212+ when needsSpace space
214+ LambdaCase -> stdCase
216+ let -- Calculate position of end of patterns. This is useful when we decide
217+ -- about putting certain constructions in hanging positions.
218+ endOfPats = case NE.nonEmpty m_pats of
219+ Nothing -> case style of
220+ Function name -> Just (getLoc name)
222+ Just pats -> (Just . getLoc . NE.last) pats
227+ hasGuards = withGuards grhssGRHSs
230+ getGRHSSpan . unLoc <$> NE.fromList grhssGRHSs
234+ (combineSrcSpans grhssSpan . srcLocSpan . srcSpanEnd)
238+ Nothing -> blockPlacement placer grhssGRHSs
240+ if onTheSameLine spn grhssSpan
241+ then blockPlacement placer grhssGRHSs
245+ if isCase style && hasGuards
248+ sep newline (located' (p_grhs' placer render groupStyle)) grhssGRHSs
250+ let whereIsEmpty = GHC.isEmptyLocalBindsPR (unLoc grhssLocalBinds)
251+ unless (GHC.eqEmptyLocalBinds (unLoc grhssLocalBinds)) $ do
254+ unless whereIsEmpty breakpoint
255+ inci $ located grhssLocalBinds p_hsLocalBinds
256+ inciIf indentBody $ do
257+ unless (length grhssGRHSs > 1) $
259+ Function _ | hasGuards -> return ()
260+ Function _ -> space >> inci equals
261+ PatternBind -> space >> inci equals
262+ s | isCase s && hasGuards -> return ()
263+ _ -> space >> txt "->"
264+ switchLayout [patGrhssSpan] $
265+ placeHanging placement p_body
267+p_match' _ _ _ _ _ _ (XGRHSs x) = noExtCon x
269+p_grhs :: GroupStyle -> GRHS GhcPs (LHsExpr GhcPs) -> R ()
270+p_grhs = p_grhs' exprPlacement p_hsExpr
274+ -- | How to get body placement
275+ (body -> Placement) ->
276+ -- | How to print body
279+ GRHS GhcPs (Located body) ->
281+p_grhs' placer render style (GRHS NoExtField guards body) =
287+ sitcc (sep commaDel (sitcc . located' p_stmt) xs)
289+ inci $ case style of
291+ RightArrow -> txt "->"
292+ placeHanging placement p_body
296+ Nothing -> placer (unLoc body)
298+ if onTheSameLine spn (getLoc body)
299+ then placer (unLoc body)
302+ case NE.nonEmpty guards of
304+ Just gs -> (Just . getLoc . NE.last) gs
305+ p_body = located body render
306+p_grhs' _ _ _ (XGRHS x) = noExtCon x
308+p_hsCmd :: HsCmd GhcPs -> R ()
310+ HsCmdArrApp NoExtField body input arrType _ -> do
311+ located body p_hsExpr
315+ HsFirstOrderApp -> txt "-<"
316+ HsHigherOrderApp -> txt "-<<"
317+ placeHanging (exprPlacement (unLoc input)) $
318+ located input p_hsExpr
319+ HsCmdArrForm NoExtField form Prefix _ cmds -> banana $ do
320+ located form p_hsExpr
321+ unless (null cmds) $ do
323+ inci (sequence_ (intersperse breakpoint (located' p_hsCmdTop <$> cmds)))
324+ HsCmdArrForm NoExtField form Infix _ [left, right] -> do
325+ located left p_hsCmdTop
327+ located form p_hsExpr
328+ placeHanging (cmdTopPlacement (unLoc right)) $
329+ located right p_hsCmdTop
330+ HsCmdArrForm NoExtField _ Infix _ _ -> notImplemented "HsCmdArrForm"
332+ -- XXX Does this ever occur in the syntax tree? It does not seem like it
333+ -- does. Open an issue and ping @yumiova if this ever occurs in output.
334+ notImplemented "HsCmdApp"
335+ HsCmdLam NoExtField mgroup -> p_matchGroup' cmdPlacement p_hsCmd Lambda mgroup
336+ HsCmdPar NoExtField c -> parens N (located c p_hsCmd)
337+ HsCmdCase NoExtField e mgroup ->
338+ p_case cmdPlacement p_hsCmd e mgroup
339+ HsCmdIf NoExtField _ if' then' else' ->
340+ p_if cmdPlacement p_hsCmd if' then' else'
341+ HsCmdLet NoExtField localBinds c ->
342+ p_let p_hsCmd localBinds c
343+ HsCmdDo NoExtField es -> do
347+ sitcc . sep newline (sitcc . withSpacing (p_stmt' cmdPlacement p_hsCmd))
348+ HsCmdWrap {} -> notImplemented "HsCmdWrap"
349+ XCmd x -> noExtCon x
351+p_hsCmdTop :: HsCmdTop GhcPs -> R ()
353+ HsCmdTop NoExtField cmd -> located cmd p_hsCmd
354+ XCmdTop x -> noExtCon x
356+-- | Render an expression preserving blank lines between such consecutive
357+-- expressions found in the original source code.
359+ -- | Rendering function
361+ -- | Entity to render
364+withSpacing f l = located l $ \x -> do
366+ UnhelpfulSpan _ -> f x
367+ RealSrcSpan currentSpn -> do
368+ getSpanMark >>= \case
369+ -- Spacing before comments will be handled by the code
370+ -- that prints comments, so we just have to deal with
371+ -- blank lines between statements here.
372+ Just (StatementSpan lastSpn) ->
373+ if srcSpanStartLine currentSpn > srcSpanEndLine lastSpn + 1
378+ -- In some cases the (f x) expression may insert a new mark. We want
379+ -- to be careful not to override comment marks.
380+ getSpanMark >>= \case
381+ Just (HaddockSpan _ _) -> return ()
382+ Just (CommentSpan _) -> return ()
383+ _ -> setSpanMark (StatementSpan currentSpn)
385+p_stmt :: Stmt GhcPs (LHsExpr GhcPs) -> R ()
386+p_stmt = p_stmt' exprPlacement p_hsExpr
391+ (body -> Placement) ->
394+ -- | Statement to render
395+ Stmt GhcPs (Located body) ->
397+p_stmt' placer render = \case
398+ LastStmt NoExtField body _ _ -> located body render
399+ BindStmt NoExtField p f _ _ -> do
408+ (mkSrcSpan (srcSpanEnd loc) (srcSpanStart l'))
411+ switchLayout [loc, getLoc f] $
412+ placeHanging placement (located f render)
413+ ApplicativeStmt {} -> notImplemented "ApplicativeStmt" -- generated by renamer
414+ BodyStmt NoExtField body _ _ -> located body render
415+ LetStmt NoExtField binds -> do
418+ sitcc $ located binds p_hsLocalBinds
420+ -- 'ParStmt' should always be eliminated in 'gatherStmt' already, such
421+ -- that it never occurs in 'p_stmt''. Consequently, handling it here
422+ -- would be redundant.
423+ notImplemented "ParStmt"
425+ -- 'TransStmt' only needs to account for render printing itself, since
426+ -- pretty printing of relevant statements (e.g., in 'trS_stmts') is
427+ -- handled through 'gatherStmt'.
428+ case (trS_form, trS_by) of
429+ (ThenForm, Nothing) -> do
432+ inci $ located trS_using p_hsExpr
433+ (ThenForm, Just e) -> do
436+ inci $ located trS_using p_hsExpr
440+ inci $ located e p_hsExpr
441+ (GroupForm, Nothing) -> do
442+ txt "then group using"
444+ inci $ located trS_using p_hsExpr
445+ (GroupForm, Just e) -> do
448+ inci $ located e p_hsExpr
452+ inci $ located trS_using p_hsExpr
456+ sitcc $ sepSemi (withSpacing (p_stmt' placer render)) recS_stmts
457+ XStmtLR c -> noExtCon c
459+gatherStmt :: ExprLStmt GhcPs -> [[ExprLStmt GhcPs]]
460+gatherStmt (L _ (ParStmt NoExtField block _ _)) =
461+ foldr ((<>) . gatherStmtBlock) [] block
462+gatherStmt (L s stmt@TransStmt {..}) =
463+ foldr liftAppend [] ((gatherStmt <$> trS_stmts) <> pure [[L s stmt]])
464+gatherStmt stmt = [[stmt]]
466+gatherStmtBlock :: ParStmtBlock GhcPs GhcPs -> [[ExprLStmt GhcPs]]
467+gatherStmtBlock (ParStmtBlock _ stmts _ _) =
468+ foldr (liftAppend . gatherStmt) [] stmts
469+gatherStmtBlock (XParStmtBlock x) = noExtCon x
471+p_hsLocalBinds :: HsLocalBindsLR GhcPs GhcPs -> R ()
472+p_hsLocalBinds = \case
473+ HsValBinds NoExtField (ValBinds NoExtField bag lsigs) -> do
474+ -- When in a single-line layout, there is a chance that the inner
475+ -- elements will also contain semicolons and they will confuse the
476+ -- parser. so we request braces around every element except the last.
477+ br <- layoutToBraces <$> getLayout
479+ let injectLeft (L l x) = L l (Left x)
480+ injectRight (L l x) = L l (Right x)
481+ in (injectLeft <$> bagToList bag) ++ (injectRight <$> lsigs)
482+ positionToBracing = \case
488+ positionToBracing p $
489+ withSpacing (either p_valDecl p_sigDecl) item
490+ binds = sortOn (srcSpanStart . getLoc) items
491+ sitcc $ sepSemi p_item' (attachRelativePos binds)
492+ HsValBinds NoExtField _ -> notImplemented "HsValBinds"
493+ HsIPBinds NoExtField (IPBinds NoExtField xs) ->
494+ -- Second argument of IPBind is always Left before type-checking.
495+ let p_ipBind (IPBind NoExtField (Left name) expr) = do
500+ useBraces $ inci $ located expr p_hsExpr
501+ p_ipBind (IPBind NoExtField (Right _) _) =
502+ -- Should only occur after the type checker
503+ notImplemented "IPBind _ (Right _) _"
504+ p_ipBind (XIPBind x) = noExtCon x
505+ in sepSemi (located' p_ipBind) xs
506+ HsIPBinds NoExtField _ -> notImplemented "HsIpBinds"
507+ EmptyLocalBinds NoExtField -> return ()
508+ XHsLocalBindsLR x -> noExtCon x
511+ HsRecField' RdrName (LHsExpr GhcPs) ->
513+p_hsRecField HsRecField {..} = do
514+ p_rdrName hsRecFieldLbl
515+ unless hsRecPun $ do
519+ if onTheSameLine (getLoc hsRecFieldLbl) (getLoc hsRecFieldArg)
520+ then exprPlacement (unLoc hsRecFieldArg)
522+ placeHanging placement (located hsRecFieldArg p_hsExpr)
524+p_hsExpr :: HsExpr GhcPs -> R ()
525+p_hsExpr = p_hsExpr' N
527+p_hsExpr' :: BracketStyle -> HsExpr GhcPs -> R ()
529+ HsVar NoExtField name -> p_rdrName name
530+ HsUnboundVar NoExtField v -> atom (unboundVarOcc v)
531+ HsConLikeOut NoExtField _ -> notImplemented "HsConLikeOut"
532+ HsRecFld NoExtField x ->
534+ Unambiguous NoExtField name -> p_rdrName name
535+ Ambiguous NoExtField name -> p_rdrName name
536+ XAmbiguousFieldOcc xx -> noExtCon xx
537+ HsOverLabel NoExtField _ v -> do
540+ HsIPVar NoExtField (HsIPName name) -> do
543+ HsOverLit NoExtField v -> atom (ol_val v)
544+ HsLit NoExtField lit ->
546+ HsString (SourceText stxt) _ -> p_stringLit stxt
547+ HsStringPrim (SourceText stxt) _ -> p_stringLit stxt
549+ HsLam NoExtField mgroup ->
550+ p_matchGroup Lambda mgroup
551+ HsLamCase NoExtField mgroup -> do
554+ inci (p_matchGroup LambdaCase mgroup)
555+ HsApp NoExtField f x -> do
556+ let -- In order to format function applications with multiple parameters
557+ -- nicer, traverse the AST to gather the function and all the
558+ -- parameters together.
559+ gatherArgs f' knownArgs =
561+ L _ (HsApp _ l r) -> gatherArgs l (r <| knownArgs)
562+ _ -> (f', knownArgs)
563+ (func, args) = gatherArgs f (x :| [])
564+ -- We need to handle the last argument specially if it is a
565+ -- hanging construct, so separate it from the rest.
566+ (initp, lastp) = (NE.init args, NE.last args)
569+ getLoc f :| [(srcLocSpan . srcSpanStart . getLoc) lastp]
570+ -- Hang the last argument only if the initial arguments span one
573+ if isOneLineSpan initSpan
574+ then exprPlacement (unLoc lastp)
576+ -- If the last argument is not hanging, just separate every argument as
577+ -- usual. If it is hanging, print the initial arguments and hang the
578+ -- last one. Also, use braces around the every argument except the last
582+ let -- Usually we want to bump indentation for arguments for the
583+ -- sake of readability. However, when the function itself is a
584+ -- do-block or case expression it is not a good idea. It seems
585+ -- to be safe to always bump indentation when the function
586+ -- expression is parenthesised.
589+ L _ (HsPar NoExtField _) -> True
590+ L _ (HsAppType NoExtField _ _) -> True
591+ L _ (HsMultiIf NoExtField _) -> True
592+ L spn _ -> isOneLineSpan spn
595+ SingleLine -> useBraces
598+ located func (p_hsExpr' s)
600+ inciIf doIndent $ sep breakpoint (located' p_hsExpr) initp
601+ inciIf doIndent $ do
602+ unless (null initp) breakpoint
603+ located lastp p_hsExpr
605+ useBraces . switchLayout [initSpan] $ do
606+ located func (p_hsExpr' s)
608+ sep breakpoint (located' p_hsExpr) initp
609+ placeHanging placement $
610+ located lastp p_hsExpr
611+ HsAppType NoExtField e a -> do
616+ -- Insert a space when the type is represented as a TH splice to avoid
617+ -- gluing @ and $ together.
618+ case unLoc (hswc_body a) of
619+ HsSpliceTy {} -> space
621+ located (hswc_body a) p_hsType
622+ OpApp NoExtField x op y -> do
623+ let opTree = OpBranch (exprOpTree x) op (exprOpTree y)
624+ p_exprOpTree s (reassociateOpTree getOpName opTree)
625+ NegApp NoExtField e _ -> do
629+ HsPar NoExtField e ->
630+ parens s (located e (dontUseBraces . p_hsExpr))
631+ SectionL NoExtField x op -> do
634+ inci (located op p_hsExpr)
635+ SectionR NoExtField op x -> do
637+ useRecordDot' <- useRecordDot
638+ let isRecordDot' = isRecordDot (unLoc op) (getLoc x)
639+ unless (useRecordDot' && isRecordDot') breakpoint
640+ inci (located x p_hsExpr)
641+ ExplicitTuple NoExtField args boxity ->
642+ let isSection = any (isMissing . unLoc) args
644+ Missing NoExtField -> True
647+ Present NoExtField x -> located x p_hsExpr
648+ Missing NoExtField -> pure ()
649+ XTupArg x -> noExtCon x
650+ p_larg = sitcc . located' p_arg
654+ Unboxed -> parensHash
657+ switchLayout [] . parens' s $
658+ sep comma p_larg args
660+ switchLayout (getLoc <$> args) . parens' s $
661+ sep commaDel p_larg args
662+ ExplicitSum NoExtField tag arity e ->
663+ p_unboxedSum N tag arity (located e p_hsExpr)
664+ HsCase NoExtField e mgroup ->
665+ p_case exprPlacement p_hsExpr e mgroup
666+ HsIf NoExtField _ if' then' else' ->
667+ p_if exprPlacement p_hsExpr if' then' else'
668+ HsMultiIf NoExtField guards -> do
671+ inci . inci $ sep newline (located' (p_grhs RightArrow)) guards
672+ HsLet NoExtField localBinds e ->
673+ p_let p_hsExpr localBinds e
674+ HsDo NoExtField ctx es -> do
675+ let doBody header = do
678+ ub <- layoutToBraces <$> getLayout
681+ (ub . withSpacing (p_stmt' exprPlacement (p_hsExpr' S)))
683+ compBody = brackets N . located es $ \xs -> do
686+ (breakpoint >> txt "|" >> space)
692+ (located' (sitcc . p_stmt))
695+ lists = foldr (liftAppend . gatherStmt) [] stmts
696+ located yield p_stmt
702+ DoExpr -> doBody "do"
703+ MDoExpr -> doBody "mdo"
704+ ListComp -> compBody
705+ MonadComp -> notImplemented "MonadComp"
706+ ArrowExpr -> notImplemented "ArrowExpr"
707+ GhciStmtCtxt -> notImplemented "GhciStmtCtxt"
708+ PatGuard _ -> notImplemented "PatGuard"
709+ ParStmtCtxt _ -> notImplemented "ParStmtCtxt"
710+ TransStmtCtxt _ -> notImplemented "TransStmtCtxt"
711+ ExplicitList _ _ xs ->
713+ sep commaDel (sitcc . located' p_hsExpr) xs
714+ RecordCon {..} -> do
715+ located rcon_con_name atom
717+ let HsRecFields {..} = rcon_flds
719+ (f :: HsRecField GhcPs (LHsExpr GhcPs))
720+ { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
722+ XFieldOcc x -> noExtCon x
724+ fields = located' (p_hsRecField . updName) <$> rec_flds
727+ Just {} -> [txt ".."]
730+ sep commaDel sitcc (fields <> dotdot)
731+ RecordUpd {..} -> do
732+ located rupd_expr p_hsExpr
733+ useRecordDot' <- useRecordDot
734+ let mrs sp = case getLoc sp of
735+ RealSrcSpan r -> Just r
738+ ((1 +) . srcSpanEndCol <$> mrs rupd_expr)
739+ == (srcSpanStartCol <$> mrs (head rupd_flds))
740+ unless (useRecordDot' && isPluginForm) breakpoint
742+ (f :: HsRecUpdField GhcPs)
743+ { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
745+ Unambiguous _ n -> n
746+ XAmbiguousFieldOcc x -> noExtCon x
751+ (sitcc . located' (p_hsRecField . updName))
753+ ExprWithTySig NoExtField x HsWC {hswc_body = HsIB {..}} -> sitcc $ do
758+ inci $ located hsib_body p_hsType
759+ ExprWithTySig NoExtField _ HsWC {hswc_body = XHsImplicitBndrs x} -> noExtCon x
760+ ExprWithTySig NoExtField _ (XHsWildCardBndrs x) -> noExtCon x
761+ ArithSeq NoExtField _ x ->
763+ From from -> brackets s $ do
764+ located from p_hsExpr
767+ FromThen from next -> brackets s $ do
768+ sep commaDel (located' p_hsExpr) [from, next]
771+ FromTo from to -> brackets s $ do
772+ located from p_hsExpr
777+ FromThenTo from next to -> brackets s $ do
778+ sep commaDel (located' p_hsExpr) [from, next]
783+ HsSCC NoExtField _ name x -> do
789+ HsCoreAnn NoExtField _ value x -> do
795+ HsBracket NoExtField x -> p_hsBracket x
796+ HsRnBracketOut {} -> notImplemented "HsRnBracketOut"
797+ HsTcBracketOut {} -> notImplemented "HsTcBracketOut"
798+ HsSpliceE NoExtField splice -> p_hsSplice splice
799+ HsProc NoExtField p e -> do
801+ located p $ \x -> do
806+ placeHanging (cmdTopPlacement (unLoc e)) $
807+ located e p_hsCmdTop
811+ inci (located e p_hsExpr)
812+ HsTick {} -> notImplemented "HsTick"
813+ HsBinTick {} -> notImplemented "HsBinTick"
814+ HsTickPragma {} -> notImplemented "HsTickPragma"
815+ HsWrap {} -> notImplemented "HsWrap"
816+ XExpr x -> noExtCon x
818+p_patSynBind :: PatSynBind GhcPs GhcPs -> R ()
819+p_patSynBind PSB {..} = do
823+ Unidirectional -> do
826+ located psb_def p_pat
827+ ImplicitBidirectional -> do
830+ located psb_def p_pat
831+ ExplicitBidirectional mgroup -> do
834+ located psb_def p_pat
838+ inci (p_matchGroup (Function psb_id) mgroup)
845+ switchLayout (getLoc <$> xs) $ do
846+ unless (null xs) breakpoint
847+ sitcc (sep breakpoint p_rdrName xs)
853+ switchLayout (getLoc . recordPatSynPatVar <$> xs) $ do
854+ unless (null xs) breakpoint
856+ sep commaDel (p_rdrName . recordPatSynPatVar) xs
859+ switchLayout [getLoc l, getLoc r] $ do
868+p_patSynBind (XPatSynBind x) = noExtCon x
873+ (body -> Placement) ->
879+ MatchGroup GhcPs (Located body) ->
881+p_case placer render e mgroup = do
888+ inci (p_matchGroup' placer render Case mgroup)
893+ (body -> Placement) ->
903+p_if placer render if' then' else' = do
906+ located if' p_hsExpr
911+ located then' $ \x ->
912+ placeHanging (placer x) (render x)
916+ located else' $ \x ->
917+ placeHanging (placer x) (render x)
923+ Located (HsLocalBindsLR GhcPs GhcPs) ->
926+p_let render localBinds e = sitcc $ do
929+ dontUseBraces $ sitcc (located localBinds p_hsLocalBinds)
930+ vlayout space (newline >> txt " ")
933+ sitcc (located e render)
935+p_pat :: Pat GhcPs -> R ()
937+ WildPat NoExtField -> txt "_"
938+ VarPat NoExtField name -> p_rdrName name
939+ LazyPat NoExtField pat -> do
942+ AsPat NoExtField name pat -> do
946+ ParPat NoExtField pat ->
947+ located pat (parens S . p_pat)
948+ BangPat NoExtField pat -> do
951+ ListPat NoExtField pats ->
952+ brackets S $ sep commaDel (located' p_pat) pats
953+ TuplePat NoExtField pats boxing -> do
957+ Unboxed -> parensHash S
958+ parens' $ sep commaDel (sitcc . located' p_pat) pats
959+ SumPat NoExtField pat tag arity ->
960+ p_unboxedSum S tag arity (located pat p_pat)
961+ ConPatIn pat details ->
963+ PrefixCon xs -> sitcc $ do
965+ unless (null xs) $ do
967+ inci . sitcc $ sep breakpoint (sitcc . located' p_pat) xs
968+ RecCon (HsRecFields fields dotdot) -> do
973+ Just x -> located x p_pat_hsRecField
974+ inci . braces N . sep commaDel f $
976+ Nothing -> Just <$> fields
977+ Just (L _ n) -> (Just <$> take n fields) ++ [Nothing]
979+ switchLayout [getLoc l, getLoc r] $ do
986+ ConPatOut {} -> notImplemented "ConPatOut" -- presumably created by renamer?
987+ ViewPat NoExtField expr pat -> sitcc $ do
988+ located expr p_hsExpr
992+ inci (located pat p_pat)
993+ SplicePat NoExtField splice -> p_hsSplice splice
994+ LitPat NoExtField p -> atom p
995+ NPat NoExtField v _ _ -> located v (atom . ol_val)
996+ NPlusKPat NoExtField n k _ _ _ -> sitcc $ do
1002+ located k (atom . ol_val)
1003+ SigPat NoExtField pat hswc -> do
1005+ p_typeAscription hswc
1006+ CoPat {} -> notImplemented "CoPat" -- apparently created at some later stage
1007+ XPat x -> noExtCon x
1009+p_pat_hsRecField :: HsRecField' (FieldOcc GhcPs) (LPat GhcPs) -> R ()
1010+p_pat_hsRecField HsRecField {..} = do
1011+ located hsRecFieldLbl $ \x ->
1012+ p_rdrName (rdrNameFieldOcc x)
1013+ unless hsRecPun $ do
1017+ inci (located hsRecFieldArg p_pat)
1019+p_unboxedSum :: BracketStyle -> ConTag -> Arity -> R () -> R ()
1020+p_unboxedSum s tag arity m = do
1021+ let before = tag - 1
1022+ after = arity - before - 1
1023+ args = replicate before Nothing <> [Just m] <> replicate after Nothing
1025+ case x :: Maybe (R ()) of
1032+ parensHash s $ sep (txt "|") f args
1034+p_hsSplice :: HsSplice GhcPs -> R ()
1036+ HsTypedSplice NoExtField deco _ expr -> p_hsSpliceTH True expr deco
1037+ HsUntypedSplice NoExtField deco _ expr -> p_hsSpliceTH False expr deco
1038+ HsQuasiQuote NoExtField _ quoterName srcSpan str -> do
1040+ p_rdrName (L srcSpan quoterName)
1042+ -- QuasiQuoters often rely on precise custom strings. We cannot do any
1043+ -- formatting here without potentially breaking someone's code.
1046+ HsSpliced {} -> notImplemented "HsSpliced"
1047+ HsSplicedT {} -> notImplemented "HsSplicedT"
1048+ XSplice x -> noExtCon x
1053+ -- | Splice expression
1055+ -- | Splice decoration
1056+ SpliceDecoration ->
1058+p_hsSpliceTH isTyped expr = \case
1061+ parens N (located expr (sitcc . p_hsExpr))
1064+ located expr (sitcc . p_hsExpr)
1066+ located expr (sitcc . p_hsExpr)
1068+ decoSymbol = if isTyped then "$$" else "$"
1070+p_hsBracket :: HsBracket GhcPs -> R ()
1072+ ExpBr NoExtField expr -> do
1073+ anns <- getEnclosingAnns
1074+ let name = case anns of
1075+ AnnOpenEQ : _ -> ""
1077+ quote name (located expr p_hsExpr)
1078+ PatBr NoExtField pat -> located pat (quote "p" . p_pat)
1079+ DecBrL NoExtField decls -> quote "d" (p_hsDecls Free decls)
1080+ DecBrG NoExtField _ -> notImplemented "DecBrG" -- result of renamer
1081+ TypBr NoExtField ty -> quote "t" (located ty p_hsType)
1082+ VarBr NoExtField isSingleQuote name -> do
1083+ txt (bool "''" "'" isSingleQuote)
1084+ -- HACK As you can see we use 'noLoc' here to be able to pass name into
1085+ -- 'p_rdrName' since the latter expects a "located" thing. The problem
1086+ -- is that 'VarBr' doesn't provide us with location of the name. This in
1087+ -- turn makes it impossible to detect if there are parentheses around
1088+ -- it, etc. So we have to add parentheses manually assuming they are
1089+ -- necessary for all operators.
1092+ (\i -> isPunctuation i || isSymbol i)
1093+ (showOutputable (rdrNameOcc name))
1094+ && not (doesNotNeedExtraParens name)
1095+ wrapper = if isOperator then parens N else id
1096+ wrapper $ p_rdrName (noLoc name)
1097+ TExpBr NoExtField expr -> do
1100+ located expr p_hsExpr
1103+ XBracket x -> noExtCon x
1105+ quote :: Text -> R () -> R ()
1106+ quote name body = do
1116+-- Print the source text of a string literal while indenting
1119+p_stringLit :: String -> R ()
1121+ let s = splitGaps src
1123+ txt $ Text.pack (mconcat s)
1125+ sitcc $ sep breakpoint (txt . Text.pack) (backslashes s)
1126+ in vlayout singleLine multiLine
1128+ -- Split a string on gaps (backslash delimited whitespaces)
1130+ -- > splitGaps "bar\\ \\fo\\&o" == ["bar", "fo\\&o"]
1131+ splitGaps :: String -> [String]
1134+ let -- A backslash and a whitespace starts a "gap"
1135+ p (Just '\\', _, _) = True
1136+ p (_, '\\', Just c) | ghcSpace c = False
1138+ in case span p (zipPrevNext s) of
1140+ let -- drop the initial '\', any amount of 'ghcSpace', and another '\'
1141+ r' = drop 1 . dropWhile ghcSpace . drop 1 $ map orig r
1142+ in map orig l : splitGaps r'
1143+ -- GHC's definition of whitespaces in strings
1144+ -- See: https://gitlab.haskell.org/ghc/ghc/blob/86753475/compiler/parser/Lexer.x#L1653
1145+ ghcSpace :: Char -> Bool
1146+ ghcSpace c = c <= '\x7f' && is_space c
1147+ -- Add backslashes to the inner side of the strings
1149+ -- > backslashes ["a", "b", "c"] == ["a\\", "\\b\\", "\\c"]
1150+ backslashes :: [String] -> [String]
1151+ backslashes (x : y : xs) = (x ++ "\\") : backslashes (('\\' : y) : xs)
1152+ backslashes xs = xs
1153+ -- Attaches previous and next items to each list element
1154+ zipPrevNext :: [a] -> [(Maybe a, a, Maybe a)]
1158+ (zip (Nothing : map Just xs) xs)
1159+ (map Just (tail xs) ++ repeat Nothing)
1160+ in map (\((p, x), n) -> (p, x, n)) z
1163+----------------------------------------------------------------------------
1166+-- | Return the wrapping function controlling the use of braces according to
1167+-- the current layout.
1168+layoutToBraces :: Layout -> R () -> R ()
1169+layoutToBraces = \case
1170+ SingleLine -> useBraces
1173+-- | Append each element in both lists with semigroups. If one list is shorter
1174+-- than the other, return the rest of the longer list unchanged.
1175+liftAppend :: Semigroup a => [a] -> [a] -> [a]
1176+liftAppend [] [] = []
1177+liftAppend [] (y : ys) = y : ys
1178+liftAppend (x : xs) [] = x : xs
1179+liftAppend (x : xs) (y : ys) = x <> y : liftAppend xs ys
1181+getGRHSSpan :: GRHS GhcPs (Located body) -> SrcSpan
1182+getGRHSSpan (GRHS NoExtField guards body) =
1183+ combineSrcSpans' $ getLoc body :| map getLoc guards
1184+getGRHSSpan (XGRHS x) = noExtCon x
1186+-- | Place a thing that may have a hanging form. This function handles how
1187+-- to separate it from preceding expressions and whether to bump indentation
1188+-- depending on what sort of expression we have.
1189+placeHanging :: Placement -> R () -> R ()
1190+placeHanging placement m =
1199+-- | Check if given block contains single expression which has a hanging
1202+ (body -> Placement) ->
1203+ [LGRHS GhcPs (Located body)] ->
1205+blockPlacement placer [L _ (GRHS NoExtField _ (L _ x))] = placer x
1206+blockPlacement _ _ = Normal
1208+-- | Check if given command has a hanging form.
1209+cmdPlacement :: HsCmd GhcPs -> Placement
1210+cmdPlacement = \case
1211+ HsCmdLam NoExtField _ -> Hanging
1212+ HsCmdCase NoExtField _ _ -> Hanging
1213+ HsCmdDo NoExtField _ -> Hanging
1216+cmdTopPlacement :: HsCmdTop GhcPs -> Placement
1217+cmdTopPlacement = \case
1218+ HsCmdTop NoExtField (L _ x) -> cmdPlacement x
1219+ XCmdTop x -> noExtCon x
1221+-- | Check if given expression has a hanging form.
1222+exprPlacement :: HsExpr GhcPs -> Placement
1223+exprPlacement = \case
1224+ -- Only hang lambdas with single line parameter lists
1225+ HsLam NoExtField mg -> case mg of
1226+ MG _ (L _ [L _ (Match NoExtField _ (x : xs) _)]) _
1227+ | isOneLineSpan (combineSrcSpans' $ fmap getLoc (x :| xs)) ->
1230+ HsLamCase NoExtField _ -> Hanging
1231+ HsCase NoExtField _ _ -> Hanging
1232+ HsDo NoExtField DoExpr _ -> Hanging
1233+ HsDo NoExtField MDoExpr _ -> Hanging
1234+ OpApp NoExtField _ op y ->
1235+ case (fmap getOpNameStr . getOpName . unLoc) op of
1236+ Just "$" -> exprPlacement (unLoc y)
1238+ HsApp NoExtField _ y -> exprPlacement (unLoc y)
1239+ HsProc NoExtField p _ ->
1240+ -- Indentation breaks if pattern is longer than one line and left
1241+ -- hanging. Consequently, only apply hanging when it is safe.
1242+ if isOneLineSpan (getLoc p)
1247+withGuards :: [LGRHS GhcPs (Located body)] -> Bool
1248+withGuards = any (checkOne . unLoc)
1250+ checkOne :: GRHS GhcPs (Located body) -> Bool
1251+ checkOne (GRHS NoExtField [] _) = False
1254+exprOpTree :: LHsExpr GhcPs -> OpTree (LHsExpr GhcPs) (LHsExpr GhcPs)
1255+exprOpTree (L _ (OpApp NoExtField x op y)) = OpBranch (exprOpTree x) op (exprOpTree y)
1256+exprOpTree n = OpNode n
1258+getOpName :: HsExpr GhcPs -> Maybe RdrName
1260+ HsVar NoExtField (L _ a) -> Just a
1263+getOpNameStr :: RdrName -> String
1264+getOpNameStr = occNameString . rdrNameOcc
1267+ -- | Bracket style to use
1269+ OpTree (LHsExpr GhcPs) (LHsExpr GhcPs) ->
1271+p_exprOpTree s (OpNode x) = located x (p_hsExpr' s)
1272+p_exprOpTree s (OpBranch x op y) = do
1273+ -- If the beginning of the first argument and the second argument are on
1274+ -- the same line, and the second argument has a hanging form, use hanging
1278+ (mkSrcSpan (srcSpanStart (opTreeLoc x)) (srcSpanStart (opTreeLoc y)))
1280+ OpNode (L _ n) -> exprPlacement n
1283+ -- Distinguish holes used in infix notation.
1284+ -- eg. '1 _foo 2' and '1 `_foo` 2'
1285+ opWrapper = case unLoc op of
1286+ HsUnboundVar NoExtField _ -> backticks
1288+ layout <- getLayout
1289+ let ub = case layout of
1290+ SingleLine -> useBraces
1291+ MultiLine -> case placement of
1292+ Hanging -> useBraces
1293+ Normal -> dontUseBraces
1294+ opNameStr = (fmap getOpNameStr . getOpName . unLoc) op
1295+ gotDollar = opNameStr == Just "$"
1296+ gotColon = opNameStr == Just ":"
1297+ gotRecordDot = isRecordDot (unLoc op) (opTreeLoc y)
1299+ switchLayout [opTreeLoc x] $
1301+ p_op = located op (opWrapper . p_hsExpr)
1302+ p_y = switchLayout [opTreeLoc y] (p_exprOpTree N y)
1303+ isSection = case (opTreeLoc x, getLoc op) of
1304+ (RealSrcSpan treeSpan, RealSrcSpan opSpan) ->
1305+ srcSpanEndCol treeSpan /= srcSpanStartCol opSpan
1308+ OpNode (L _ HsDo {}) -> True
1310+ useRecordDot' <- useRecordDot
1322+ inciIf (isDoBlock y) p_y
1324+ && isOneLineSpan (opTreeLoc x)
1325+ && placement == Normal -> do
1331+ | useRecordDot' && gotRecordDot -> do
1333+ when isSection space
1338+ placeHanging placement $ do
1343+-- | Return 'True' if given expression is a record-dot operator expression.
1345+ -- | Operator expression
1347+ -- | Span of the expression on the right-hand side of the operator
1350+isRecordDot op (RealSrcSpan ySpan) = case op of
1351+ HsVar NoExtField (L (RealSrcSpan opSpan) opName) ->
1352+ (getOpNameStr opName == ".") && (srcSpanEndCol opSpan == srcSpanStartCol ySpan)
1354+isRecordDot _ _ = False
1356+-- | Get annotations for the enclosing element.
1357+getEnclosingAnns :: R [AnnKeywordId]
1358+getEnclosingAnns = do
1359+ e <- getEnclosingSpan (const True)
1361+ Nothing -> return []
1362+ Just e' -> getAnns (RealSrcSpan e')