{- (c) The University of Glasgow 2006-2012 (c) The GRASP Project, Glasgow University, 1992-1998 -} -- | This module defines classes and functions for pretty-printing. It also -- exports a number of helpful debugging and other utilities such as 'trace' and 'panic'. -- -- The interface to this module is very similar to the standard Hughes-PJ pretty printing -- module, except that it exports a number of additional functions that are rarely used, -- and works over the 'SDoc' type. module Outputable ( -- * Type classes Outputable(..), OutputableBndr(..), -- * Pretty printing combinators SDoc, runSDoc, initSDocContext, docToSDoc, interppSP, interpp'SP, pprQuotedList, pprWithCommas, quotedListWithOr, quotedListWithNor, pprWithBars, empty, isEmpty, nest, char, text, ftext, ptext, ztext, int, intWithCommas, integer, word, float, double, rational, doublePrec, parens, cparen, brackets, braces, quotes, quote, doubleQuotes, angleBrackets, semi, comma, colon, dcolon, space, equals, dot, vbar, arrow, larrow, darrow, arrowt, larrowt, arrowtt, larrowtt, lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore, blankLine, forAllLit, kindType, bullet, (<>), (<+>), hcat, hsep, ($$), ($+$), vcat, sep, cat, fsep, fcat, hang, hangNotEmpty, punctuate, ppWhen, ppUnless, speakNth, speakN, speakNOf, plural, isOrAre, doOrDoes, unicodeSyntax, coloured, keyword, -- * Converting 'SDoc' into strings and outputing it printSDoc, printSDocLn, printForUser, printForUserPartWay, printForC, bufLeftRenderSDoc, pprCode, mkCodeStyle, showSDoc, showSDocUnsafe, showSDocOneLine, showSDocForUser, showSDocDebug, showSDocDump, showSDocDumpOneLine, showSDocUnqual, showPpr, renderWithStyle, pprInfixVar, pprPrefixVar, pprHsChar, pprHsString, pprHsBytes, primFloatSuffix, primCharSuffix, primWordSuffix, primDoubleSuffix, primInt64Suffix, primWord64Suffix, primIntSuffix, pprPrimChar, pprPrimInt, pprPrimWord, pprPrimInt64, pprPrimWord64, pprFastFilePath, -- * Controlling the style in which output is printed BindingSite(..), PprStyle, CodeStyle(..), PrintUnqualified(..), QueryQualifyName, QueryQualifyModule, QueryQualifyPackage, reallyAlwaysQualify, reallyAlwaysQualifyNames, alwaysQualify, alwaysQualifyNames, alwaysQualifyModules, neverQualify, neverQualifyNames, neverQualifyModules, alwaysQualifyPackages, neverQualifyPackages, QualifyName(..), queryQual, sdocWithDynFlags, sdocWithPlatform, updSDocDynFlags, getPprStyle, withPprStyle, withPprStyleDoc, setStyleColoured, pprDeeper, pprDeeperList, pprSetDepth, codeStyle, userStyle, debugStyle, dumpStyle, asmStyle, qualName, qualModule, qualPackage, mkErrStyle, defaultErrStyle, defaultDumpStyle, mkDumpStyle, defaultUserStyle, mkUserStyle, cmdlineParserStyle, Depth(..), ifPprDebug, whenPprDebug, getPprDebug, -- * Error handling and debugging utilities pprPanic, pprSorry, assertPprPanic, pprPgmError, pprTrace, pprTraceDebug, pprTraceIt, warnPprTrace, pprSTrace, pprTraceException, pprTraceM, trace, pgmError, panic, sorry, assertPanic, pprDebugAndThen, callStackDoc, ) where import GhcPrelude import {-# SOURCE #-} DynFlags( DynFlags, hasPprDebug, hasNoDebugOutput, targetPlatform, pprUserLength, pprCols, useUnicode, useUnicodeSyntax, useStarIsType, shouldUseColor, unsafeGlobalDynFlags, shouldUseHexWordLiterals ) import {-# SOURCE #-} Module( UnitId, Module, ModuleName, moduleName ) import {-# SOURCE #-} OccName( OccName ) import BufWrite (BufHandle) import FastString import qualified Pretty import Util import Platform import qualified PprColour as Col import Pretty ( Doc, Mode(..) ) import Panic import GHC.Serialized import GHC.LanguageExtensions (Extension) import Control.Exception (finally) import Data.ByteString (ByteString) import qualified Data.ByteString as BS import Data.Char import qualified Data.Map as M import Data.Int import qualified Data.IntMap as IM import Data.Set (Set) import qualified Data.Set as Set import Data.String import Data.Word import System.IO ( Handle ) import System.FilePath import Text.Printf import Numeric (showFFloat) import Data.Graph (SCC(..)) import Data.List (intersperse) import GHC.Fingerprint import GHC.Show ( showMultiLineString ) import GHC.Stack ( callStack, prettyCallStack ) import Control.Monad.IO.Class import Exception {- ************************************************************************ * * \subsection{The @PprStyle@ data type} * * ************************************************************************ -} data PprStyle = PprUser PrintUnqualified Depth Coloured -- Pretty-print in a way that will make sense to the -- ordinary user; must be very close to Haskell -- syntax, etc. -- Assumes printing tidied code: non-system names are -- printed without uniques. | PprDump PrintUnqualified -- For -ddump-foo; less verbose than PprDebug, but more than PprUser -- Does not assume tidied code: non-external names -- are printed with uniques. | PprDebug -- Full debugging output | PprCode CodeStyle -- Print code; either C or assembler data CodeStyle = CStyle -- The format of labels differs for C and assembler | AsmStyle data Depth = AllTheWay | PartWay Int -- 0 => stop data Coloured = Uncoloured | Coloured -- ----------------------------------------------------------------------------- -- Printing original names -- | When printing code that contains original names, we need to map the -- original names back to something the user understands. This is the -- purpose of the triple of functions that gets passed around -- when rendering 'SDoc'. data PrintUnqualified = QueryQualify { queryQualifyName :: QueryQualifyName, queryQualifyModule :: QueryQualifyModule, queryQualifyPackage :: QueryQualifyPackage } -- | Given a `Name`'s `Module` and `OccName`, decide whether and how to qualify -- it. type QueryQualifyName = Module -> OccName -> QualifyName -- | For a given module, we need to know whether to print it with -- a package name to disambiguate it. type QueryQualifyModule = Module -> Bool -- | For a given package, we need to know whether to print it with -- the component id to disambiguate it. type QueryQualifyPackage = UnitId -> Bool -- See Note [Printing original names] in HscTypes data QualifyName -- Given P:M.T = NameUnqual -- It's in scope unqualified as "T" -- OR nothing called "T" is in scope | NameQual ModuleName -- It's in scope qualified as "X.T" | NameNotInScope1 -- It's not in scope at all, but M.T is not bound -- in the current scope, so we can refer to it as "M.T" | NameNotInScope2 -- It's not in scope at all, and M.T is already bound in -- the current scope, so we must refer to it as "P:M.T" instance Outputable QualifyName where ppr NameUnqual = text "NameUnqual" ppr (NameQual _mod) = text "NameQual" -- can't print the mod without module loops :( ppr NameNotInScope1 = text "NameNotInScope1" ppr NameNotInScope2 = text "NameNotInScope2" reallyAlwaysQualifyNames :: QueryQualifyName reallyAlwaysQualifyNames _ _ = NameNotInScope2 -- | NB: This won't ever show package IDs alwaysQualifyNames :: QueryQualifyName alwaysQualifyNames m _ = NameQual (moduleName m) neverQualifyNames :: QueryQualifyName neverQualifyNames _ _ = NameUnqual alwaysQualifyModules :: QueryQualifyModule alwaysQualifyModules _ = True neverQualifyModules :: QueryQualifyModule neverQualifyModules _ = False alwaysQualifyPackages :: QueryQualifyPackage alwaysQualifyPackages _ = True neverQualifyPackages :: QueryQualifyPackage neverQualifyPackages _ = False reallyAlwaysQualify, alwaysQualify, neverQualify :: PrintUnqualified reallyAlwaysQualify = QueryQualify reallyAlwaysQualifyNames alwaysQualifyModules alwaysQualifyPackages alwaysQualify = QueryQualify alwaysQualifyNames alwaysQualifyModules alwaysQualifyPackages neverQualify = QueryQualify neverQualifyNames neverQualifyModules neverQualifyPackages defaultUserStyle :: DynFlags -> PprStyle defaultUserStyle dflags = mkUserStyle dflags neverQualify AllTheWay defaultDumpStyle :: DynFlags -> PprStyle -- Print without qualifiers to reduce verbosity, unless -dppr-debug defaultDumpStyle dflags | hasPprDebug dflags = PprDebug | otherwise = PprDump neverQualify mkDumpStyle :: DynFlags -> PrintUnqualified -> PprStyle mkDumpStyle dflags print_unqual | hasPprDebug dflags = PprDebug | otherwise = PprDump print_unqual defaultErrStyle :: DynFlags -> PprStyle -- Default style for error messages, when we don't know PrintUnqualified -- It's a bit of a hack because it doesn't take into account what's in scope -- Only used for desugarer warnings, and typechecker errors in interface sigs -- NB that -dppr-debug will still get into PprDebug style defaultErrStyle dflags = mkErrStyle dflags neverQualify -- | Style for printing error messages mkErrStyle :: DynFlags -> PrintUnqualified -> PprStyle mkErrStyle dflags qual = mkUserStyle dflags qual (PartWay (pprUserLength dflags)) cmdlineParserStyle :: DynFlags -> PprStyle cmdlineParserStyle dflags = mkUserStyle dflags alwaysQualify AllTheWay mkUserStyle :: DynFlags -> PrintUnqualified -> Depth -> PprStyle mkUserStyle dflags unqual depth | hasPprDebug dflags = PprDebug | otherwise = PprUser unqual depth Uncoloured setStyleColoured :: Bool -> PprStyle -> PprStyle setStyleColoured col style = case style of PprUser q d _ -> PprUser q d c _ -> style where c | col = Coloured | otherwise = Uncoloured instance Outputable PprStyle where ppr (PprUser {}) = text "user-style" ppr (PprCode {}) = text "code-style" ppr (PprDump {}) = text "dump-style" ppr (PprDebug {}) = text "debug-style" {- Orthogonal to the above printing styles are (possibly) some command-line flags that affect printing (often carried with the style). The most likely ones are variations on how much type info is shown. The following test decides whether or not we are actually generating code (either C or assembly), or generating interface files. ************************************************************************ * * \subsection{The @SDoc@ data type} * * ************************************************************************ -} -- | Represents a pretty-printable document. -- -- To display an 'SDoc', use 'printSDoc', 'printSDocLn', 'bufLeftRenderSDoc', -- or 'renderWithStyle'. Avoid calling 'runSDoc' directly as it breaks the -- abstraction layer. newtype SDoc = SDoc { runSDoc :: SDocContext -> Doc } data SDocContext = SDC { sdocStyle :: !PprStyle , sdocLastColour :: !Col.PprColour -- ^ The most recently used colour. This allows nesting colours. , sdocDynFlags :: !DynFlags } instance IsString SDoc where fromString = text initSDocContext :: DynFlags -> PprStyle -> SDocContext initSDocContext dflags sty = SDC { sdocStyle = sty , sdocLastColour = Col.colReset , sdocDynFlags = dflags } withPprStyle :: PprStyle -> SDoc -> SDoc withPprStyle sty d = SDoc $ \ctxt -> runSDoc d ctxt{sdocStyle=sty} -- | This is not a recommended way to render 'SDoc', since it breaks the -- abstraction layer of 'SDoc'. Prefer to use 'printSDoc', 'printSDocLn', -- 'bufLeftRenderSDoc', or 'renderWithStyle' instead. withPprStyleDoc :: DynFlags -> PprStyle -> SDoc -> Doc withPprStyleDoc dflags sty d = runSDoc d (initSDocContext dflags sty) pprDeeper :: SDoc -> SDoc pprDeeper d = SDoc $ \ctx -> case ctx of SDC{sdocStyle=PprUser _ (PartWay 0) _} -> Pretty.text "..." SDC{sdocStyle=PprUser q (PartWay n) c} -> runSDoc d ctx{sdocStyle = PprUser q (PartWay (n-1)) c} _ -> runSDoc d ctx -- | Truncate a list that is longer than the current depth. pprDeeperList :: ([SDoc] -> SDoc) -> [SDoc] -> SDoc pprDeeperList f ds | null ds = f [] | otherwise = SDoc work where work ctx@SDC{sdocStyle=PprUser q (PartWay n) c} | n==0 = Pretty.text "..." | otherwise = runSDoc (f (go 0 ds)) ctx{sdocStyle = PprUser q (PartWay (n-1)) c} where go _ [] = [] go i (d:ds) | i >= n = [text "...."] | otherwise = d : go (i+1) ds work other_ctx = runSDoc (f ds) other_ctx pprSetDepth :: Depth -> SDoc -> SDoc pprSetDepth depth doc = SDoc $ \ctx -> case ctx of SDC{sdocStyle=PprUser q _ c} -> runSDoc doc ctx{sdocStyle = PprUser q depth c} _ -> runSDoc doc ctx getPprStyle :: (PprStyle -> SDoc) -> SDoc getPprStyle df = SDoc $ \ctx -> runSDoc (df (sdocStyle ctx)) ctx sdocWithDynFlags :: (DynFlags -> SDoc) -> SDoc sdocWithDynFlags f = SDoc $ \ctx -> runSDoc (f (sdocDynFlags ctx)) ctx sdocWithPlatform :: (Platform -> SDoc) -> SDoc sdocWithPlatform f = sdocWithDynFlags (f . targetPlatform) updSDocDynFlags :: (DynFlags -> DynFlags) -> SDoc -> SDoc updSDocDynFlags upd doc = SDoc $ \ctx -> runSDoc doc (ctx { sdocDynFlags = upd (sdocDynFlags ctx) }) qualName :: PprStyle -> QueryQualifyName qualName (PprUser q _ _) mod occ = queryQualifyName q mod occ qualName (PprDump q) mod occ = queryQualifyName q mod occ qualName _other mod _ = NameQual (moduleName mod) qualModule :: PprStyle -> QueryQualifyModule qualModule (PprUser q _ _) m = queryQualifyModule q m qualModule (PprDump q) m = queryQualifyModule q m qualModule _other _m = True qualPackage :: PprStyle -> QueryQualifyPackage qualPackage (PprUser q _ _) m = queryQualifyPackage q m qualPackage (PprDump q) m = queryQualifyPackage q m qualPackage _other _m = True queryQual :: PprStyle -> PrintUnqualified queryQual s = QueryQualify (qualName s) (qualModule s) (qualPackage s) codeStyle :: PprStyle -> Bool codeStyle (PprCode _) = True codeStyle _ = False asmStyle :: PprStyle -> Bool asmStyle (PprCode AsmStyle) = True asmStyle _other = False dumpStyle :: PprStyle -> Bool dumpStyle (PprDump {}) = True dumpStyle _other = False debugStyle :: PprStyle -> Bool debugStyle PprDebug = True debugStyle _other = False userStyle :: PprStyle -> Bool userStyle (PprUser {}) = True userStyle _other = False getPprDebug :: (Bool -> SDoc) -> SDoc getPprDebug d = getPprStyle $ \ sty -> d (debugStyle sty) ifPprDebug :: SDoc -> SDoc -> SDoc -- ^ Says what to do with and without -dppr-debug ifPprDebug yes no = getPprDebug $ \ dbg -> if dbg then yes else no whenPprDebug :: SDoc -> SDoc -- Empty for non-debug style -- ^ Says what to do with -dppr-debug; without, return empty whenPprDebug d = ifPprDebug d empty -- | The analog of 'Pretty.printDoc_' for 'SDoc', which tries to make sure the -- terminal doesn't get screwed up by the ANSI color codes if an exception -- is thrown during pretty-printing. printSDoc :: Mode -> DynFlags -> Handle -> PprStyle -> SDoc -> IO () printSDoc mode dflags handle sty doc = Pretty.printDoc_ mode cols handle (runSDoc doc ctx) `finally` Pretty.printDoc_ mode cols handle (runSDoc (coloured Col.colReset empty) ctx) where cols = pprCols dflags ctx = initSDocContext dflags sty -- | Like 'printSDoc' but appends an extra newline. printSDocLn :: Mode -> DynFlags -> Handle -> PprStyle -> SDoc -> IO () printSDocLn mode dflags handle sty doc = printSDoc mode dflags handle sty (doc $$ text "") printForUser :: DynFlags -> Handle -> PrintUnqualified -> SDoc -> IO () printForUser dflags handle unqual doc = printSDocLn PageMode dflags handle (mkUserStyle dflags unqual AllTheWay) doc printForUserPartWay :: DynFlags -> Handle -> Int -> PrintUnqualified -> SDoc -> IO () printForUserPartWay dflags handle d unqual doc = printSDocLn PageMode dflags handle (mkUserStyle dflags unqual (PartWay d)) doc -- | Like 'printSDocLn' but specialized with 'LeftMode' and -- @'PprCode' 'CStyle'@. This is typically used to output C-- code. printForC :: DynFlags -> Handle -> SDoc -> IO () printForC dflags handle doc = printSDocLn LeftMode dflags handle (PprCode CStyle) doc -- | An efficient variant of 'printSDoc' specialized for 'LeftMode' that -- outputs to a 'BufHandle'. bufLeftRenderSDoc :: DynFlags -> BufHandle -> PprStyle -> SDoc -> IO () bufLeftRenderSDoc dflags bufHandle sty doc = Pretty.bufLeftRender bufHandle (runSDoc doc (initSDocContext dflags sty)) pprCode :: CodeStyle -> SDoc -> SDoc pprCode cs d = withPprStyle (PprCode cs) d mkCodeStyle :: CodeStyle -> PprStyle mkCodeStyle = PprCode -- Can't make SDoc an instance of Show because SDoc is just a function type -- However, Doc *is* an instance of Show -- showSDoc just blasts it out as a string showSDoc :: DynFlags -> SDoc -> String showSDoc dflags sdoc = renderWithStyle dflags sdoc (defaultUserStyle dflags) -- showSDocUnsafe is unsafe, because `unsafeGlobalDynFlags` might not be -- initialised yet. showSDocUnsafe :: SDoc -> String showSDocUnsafe sdoc = showSDoc unsafeGlobalDynFlags sdoc showPpr :: Outputable a => DynFlags -> a -> String showPpr dflags thing = showSDoc dflags (ppr thing) showSDocUnqual :: DynFlags -> SDoc -> String -- Only used by Haddock showSDocUnqual dflags sdoc = showSDoc dflags sdoc showSDocForUser :: DynFlags -> PrintUnqualified -> SDoc -> String -- Allows caller to specify the PrintUnqualified to use showSDocForUser dflags unqual doc = renderWithStyle dflags doc (mkUserStyle dflags unqual AllTheWay) showSDocDump :: DynFlags -> SDoc -> String showSDocDump dflags d = renderWithStyle dflags d (defaultDumpStyle dflags) showSDocDebug :: DynFlags -> SDoc -> String showSDocDebug dflags d = renderWithStyle dflags d PprDebug renderWithStyle :: DynFlags -> SDoc -> PprStyle -> String renderWithStyle dflags sdoc sty = let s = Pretty.style{ Pretty.mode = PageMode, Pretty.lineLength = pprCols dflags } in Pretty.renderStyle s $ runSDoc sdoc (initSDocContext dflags sty) -- This shows an SDoc, but on one line only. It's cheaper than a full -- showSDoc, designed for when we're getting results like "Foo.bar" -- and "foo{uniq strictness}" so we don't want fancy layout anyway. showSDocOneLine :: DynFlags -> SDoc -> String showSDocOneLine dflags d = let s = Pretty.style{ Pretty.mode = OneLineMode, Pretty.lineLength = pprCols dflags } in Pretty.renderStyle s $ runSDoc d (initSDocContext dflags (defaultUserStyle dflags)) showSDocDumpOneLine :: DynFlags -> SDoc -> String showSDocDumpOneLine dflags d = let s = Pretty.style{ Pretty.mode = OneLineMode, Pretty.lineLength = irrelevantNCols } in Pretty.renderStyle s $ runSDoc d (initSDocContext dflags (defaultDumpStyle dflags)) irrelevantNCols :: Int -- Used for OneLineMode and LeftMode when number of cols isn't used irrelevantNCols = 1 isEmpty :: DynFlags -> SDoc -> Bool isEmpty dflags sdoc = Pretty.isEmpty $ runSDoc sdoc dummySDocContext where dummySDocContext = initSDocContext dflags PprDebug docToSDoc :: Doc -> SDoc docToSDoc d = SDoc (\_ -> d) empty :: SDoc char :: Char -> SDoc text :: String -> SDoc ftext :: FastString -> SDoc ptext :: LitString -> SDoc ztext :: FastZString -> SDoc int :: Int -> SDoc integer :: Integer -> SDoc word :: Integer -> SDoc float :: Float -> SDoc double :: Double -> SDoc rational :: Rational -> SDoc empty = docToSDoc $ Pretty.empty char c = docToSDoc $ Pretty.char c text s = docToSDoc $ Pretty.text s {-# INLINE text #-} -- Inline so that the RULE Pretty.text will fire ftext s = docToSDoc $ Pretty.ftext s ptext s = docToSDoc $ Pretty.ptext s ztext s = docToSDoc $ Pretty.ztext s int n = docToSDoc $ Pretty.int n integer n = docToSDoc $ Pretty.integer n float n = docToSDoc $ Pretty.float n double n = docToSDoc $ Pretty.double n rational n = docToSDoc $ Pretty.rational n word n = sdocWithDynFlags $ \dflags -> -- See Note [Print Hexadecimal Literals] in Pretty.hs if shouldUseHexWordLiterals dflags then docToSDoc $ Pretty.hex n else docToSDoc $ Pretty.integer n -- | @doublePrec p n@ shows a floating point number @n@ with @p@ -- digits of precision after the decimal point. doublePrec :: Int -> Double -> SDoc doublePrec p n = text (showFFloat (Just p) n "") parens, braces, brackets, quotes, quote, doubleQuotes, angleBrackets :: SDoc -> SDoc parens d = SDoc $ Pretty.parens . runSDoc d braces d = SDoc $ Pretty.braces . runSDoc d brackets d = SDoc $ Pretty.brackets . runSDoc d quote d = SDoc $ Pretty.quote . runSDoc d doubleQuotes d = SDoc $ Pretty.doubleQuotes . runSDoc d angleBrackets d = char '<' <> d <> char '>' cparen :: Bool -> SDoc -> SDoc cparen b d = SDoc $ Pretty.maybeParens b . runSDoc d -- 'quotes' encloses something in single quotes... -- but it omits them if the thing begins or ends in a single quote -- so that we don't get `foo''. Instead we just have foo'. quotes d = sdocWithDynFlags $ \dflags -> if useUnicode dflags then char '‘' <> d <> char '’' else SDoc $ \sty -> let pp_d = runSDoc d sty str = show pp_d in case (str, snocView str) of (_, Just (_, '\'')) -> pp_d ('\'' : _, _) -> pp_d _other -> Pretty.quotes pp_d semi, comma, colon, equals, space, dcolon, underscore, dot, vbar :: SDoc arrow, larrow, darrow, arrowt, larrowt, arrowtt, larrowtt :: SDoc lparen, rparen, lbrack, rbrack, lbrace, rbrace, blankLine :: SDoc blankLine = docToSDoc $ Pretty.text "" dcolon = unicodeSyntax (char '∷') (docToSDoc $ Pretty.text "::") arrow = unicodeSyntax (char '→') (docToSDoc $ Pretty.text "->") larrow = unicodeSyntax (char '←') (docToSDoc $ Pretty.text "<-") darrow = unicodeSyntax (char '⇒') (docToSDoc $ Pretty.text "=>") arrowt = unicodeSyntax (char '⤚') (docToSDoc $ Pretty.text ">-") larrowt = unicodeSyntax (char '⤙') (docToSDoc $ Pretty.text "-<") arrowtt = unicodeSyntax (char '⤜') (docToSDoc $ Pretty.text ">>-") larrowtt = unicodeSyntax (char '⤛') (docToSDoc $ Pretty.text "-<<") semi = docToSDoc $ Pretty.semi comma = docToSDoc $ Pretty.comma colon = docToSDoc $ Pretty.colon equals = docToSDoc $ Pretty.equals space = docToSDoc $ Pretty.space underscore = char '_' dot = char '.' vbar = char '|' lparen = docToSDoc $ Pretty.lparen rparen = docToSDoc $ Pretty.rparen lbrack = docToSDoc $ Pretty.lbrack rbrack = docToSDoc $ Pretty.rbrack lbrace = docToSDoc $ Pretty.lbrace rbrace = docToSDoc $ Pretty.rbrace forAllLit :: SDoc forAllLit = unicodeSyntax (char '∀') (text "forall") kindType :: SDoc kindType = sdocWithDynFlags $ \dflags -> if useStarIsType dflags then unicodeSyntax (char '★') (char '*') else text "Type" bullet :: SDoc bullet = unicode (char '•') (char '*') unicodeSyntax :: SDoc -> SDoc -> SDoc unicodeSyntax unicode plain = sdocWithDynFlags $ \dflags -> if useUnicode dflags && useUnicodeSyntax dflags then unicode else plain unicode :: SDoc -> SDoc -> SDoc unicode unicode plain = sdocWithDynFlags $ \dflags -> if useUnicode dflags then unicode else plain nest :: Int -> SDoc -> SDoc -- ^ Indent 'SDoc' some specified amount (<>) :: SDoc -> SDoc -> SDoc -- ^ Join two 'SDoc' together horizontally without a gap (<+>) :: SDoc -> SDoc -> SDoc -- ^ Join two 'SDoc' together horizontally with a gap between them ($$) :: SDoc -> SDoc -> SDoc -- ^ Join two 'SDoc' together vertically; if there is -- no vertical overlap it "dovetails" the two onto one line ($+$) :: SDoc -> SDoc -> SDoc -- ^ Join two 'SDoc' together vertically nest n d = SDoc $ Pretty.nest n . runSDoc d (<>) d1 d2 = SDoc $ \sty -> (Pretty.<>) (runSDoc d1 sty) (runSDoc d2 sty) (<+>) d1 d2 = SDoc $ \sty -> (Pretty.<+>) (runSDoc d1 sty) (runSDoc d2 sty) ($$) d1 d2 = SDoc $ \sty -> (Pretty.$$) (runSDoc d1 sty) (runSDoc d2 sty) ($+$) d1 d2 = SDoc $ \sty -> (Pretty.$+$) (runSDoc d1 sty) (runSDoc d2 sty) hcat :: [SDoc] -> SDoc -- ^ Concatenate 'SDoc' horizontally hsep :: [SDoc] -> SDoc -- ^ Concatenate 'SDoc' horizontally with a space between each one vcat :: [SDoc] -> SDoc -- ^ Concatenate 'SDoc' vertically with dovetailing sep :: [SDoc] -> SDoc -- ^ Separate: is either like 'hsep' or like 'vcat', depending on what fits cat :: [SDoc] -> SDoc -- ^ Catenate: is either like 'hcat' or like 'vcat', depending on what fits fsep :: [SDoc] -> SDoc -- ^ A paragraph-fill combinator. It's much like sep, only it -- keeps fitting things on one line until it can't fit any more. fcat :: [SDoc] -> SDoc -- ^ This behaves like 'fsep', but it uses '<>' for horizontal conposition rather than '<+>' hcat ds = SDoc $ \sty -> Pretty.hcat [runSDoc d sty | d <- ds] hsep ds = SDoc $ \sty -> Pretty.hsep [runSDoc d sty | d <- ds] vcat ds = SDoc $ \sty -> Pretty.vcat [runSDoc d sty | d <- ds] sep ds = SDoc $ \sty -> Pretty.sep [runSDoc d sty | d <- ds] cat ds = SDoc $ \sty -> Pretty.cat [runSDoc d sty | d <- ds] fsep ds = SDoc $ \sty -> Pretty.fsep [runSDoc d sty | d <- ds] fcat ds = SDoc $ \sty -> Pretty.fcat [runSDoc d sty | d <- ds] hang :: SDoc -- ^ The header -> Int -- ^ Amount to indent the hung body -> SDoc -- ^ The hung body, indented and placed below the header -> SDoc hang d1 n d2 = SDoc $ \sty -> Pretty.hang (runSDoc d1 sty) n (runSDoc d2 sty) -- | This behaves like 'hang', but does not indent the second document -- when the header is empty. hangNotEmpty :: SDoc -> Int -> SDoc -> SDoc hangNotEmpty d1 n d2 = SDoc $ \sty -> Pretty.hangNotEmpty (runSDoc d1 sty) n (runSDoc d2 sty) punctuate :: SDoc -- ^ The punctuation -> [SDoc] -- ^ The list that will have punctuation added between every adjacent pair of elements -> [SDoc] -- ^ Punctuated list punctuate _ [] = [] punctuate p (d:ds) = go d ds where go d [] = [d] go d (e:es) = (d <> p) : go e es ppWhen, ppUnless :: Bool -> SDoc -> SDoc ppWhen True doc = doc ppWhen False _ = empty ppUnless True _ = empty ppUnless False doc = doc -- | Apply the given colour\/style for the argument. -- -- Only takes effect if colours are enabled. coloured :: Col.PprColour -> SDoc -> SDoc coloured col sdoc = sdocWithDynFlags $ \dflags -> if shouldUseColor dflags then SDoc $ \ctx@SDC{ sdocLastColour = lastCol } -> case ctx of SDC{ sdocStyle = PprUser _ _ Coloured } -> let ctx' = ctx{ sdocLastColour = lastCol `mappend` col } in Pretty.zeroWidthText (Col.renderColour col) Pretty.<> runSDoc sdoc ctx' Pretty.<> Pretty.zeroWidthText (Col.renderColourAfresh lastCol) _ -> runSDoc sdoc ctx else sdoc keyword :: SDoc -> SDoc keyword = coloured Col.colBold {- ************************************************************************ * * \subsection[Outputable-class]{The @Outputable@ class} * * ************************************************************************ -} -- | Class designating that some type has an 'SDoc' representation class Outputable a where ppr :: a -> SDoc pprPrec :: Rational -> a -> SDoc -- 0 binds least tightly -- We use Rational because there is always a -- Rational between any other two Rationals ppr = pprPrec 0 pprPrec _ = ppr instance Outputable Char where ppr c = text [c] instance Outputable Bool where ppr True = text "True" ppr False = text "False" instance Outputable Ordering where ppr LT = text "LT" ppr EQ = text "EQ" ppr GT = text "GT" instance Outputable Int32 where ppr n = integer $ fromIntegral n instance Outputable Int64 where ppr n = integer $ fromIntegral n instance Outputable Int where ppr n = int n instance Outputable Integer where ppr n = integer n instance Outputable Word16 where ppr n = integer $ fromIntegral n instance Outputable Word32 where ppr n = integer $ fromIntegral n instance Outputable Word where ppr n = integer $ fromIntegral n instance Outputable () where ppr _ = text "()" instance (Outputable a) => Outputable [a] where ppr xs = brackets (fsep (punctuate comma (map ppr xs))) instance (Outputable a) => Outputable (Set a) where ppr s = braces (fsep (punctuate comma (map ppr (Set.toList s)))) instance (Outputable a, Outputable b) => Outputable (a, b) where ppr (x,y) = parens (sep [ppr x <> comma, ppr y]) instance Outputable a => Outputable (Maybe a) where ppr Nothing = text "Nothing" ppr (Just x) = text "Just" <+> ppr x instance (Outputable a, Outputable b) => Outputable (Either a b) where ppr (Left x) = text "Left" <+> ppr x ppr (Right y) = text "Right" <+> ppr y -- ToDo: may not be used instance (Outputable a, Outputable b, Outputable c) => Outputable (a, b, c) where ppr (x,y,z) = parens (sep [ppr x <> comma, ppr y <> comma, ppr z ]) instance (Outputable a, Outputable b, Outputable c, Outputable d) => Outputable (a, b, c, d) where ppr (a,b,c,d) = parens (sep [ppr a <> comma, ppr b <> comma, ppr c <> comma, ppr d]) instance (Outputable a, Outputable b, Outputable c, Outputable d, Outputable e) => Outputable (a, b, c, d, e) where ppr (a,b,c,d,e) = parens (sep [ppr a <> comma, ppr b <> comma, ppr c <> comma, ppr d <> comma, ppr e]) instance (Outputable a, Outputable b, Outputable c, Outputable d, Outputable e, Outputable f) => Outputable (a, b, c, d, e, f) where ppr (a,b,c,d,e,f) = parens (sep [ppr a <> comma, ppr b <> comma, ppr c <> comma, ppr d <> comma, ppr e <> comma, ppr f]) instance (Outputable a, Outputable b, Outputable c, Outputable d, Outputable e, Outputable f, Outputable g) => Outputable (a, b, c, d, e, f, g) where ppr (a,b,c,d,e,f,g) = parens (sep [ppr a <> comma, ppr b <> comma, ppr c <> comma, ppr d <> comma, ppr e <> comma, ppr f <> comma, ppr g]) instance Outputable FastString where ppr fs = ftext fs -- Prints an unadorned string, -- no double quotes or anything instance (Outputable key, Outputable elt) => Outputable (M.Map key elt) where ppr m = ppr (M.toList m) instance (Outputable elt) => Outputable (IM.IntMap elt) where ppr m = ppr (IM.toList m) instance Outputable Fingerprint where ppr (Fingerprint w1 w2) = text (printf "%016x%016x" w1 w2) instance Outputable a => Outputable (SCC a) where ppr (AcyclicSCC v) = text "NONREC" $$ (nest 3 (ppr v)) ppr (CyclicSCC vs) = text "REC" $$ (nest 3 (vcat (map ppr vs))) instance Outputable Serialized where ppr (Serialized the_type bytes) = int (length bytes) <+> text "of type" <+> text (show the_type) instance Outputable Extension where ppr = text . show {- ************************************************************************ * * \subsection{The @OutputableBndr@ class} * * ************************************************************************ -} -- | 'BindingSite' is used to tell the thing that prints binder what -- language construct is binding the identifier. This can be used -- to decide how much info to print. -- Also see Note [Binding-site specific printing] in PprCore data BindingSite = LambdaBind -- ^ The x in (\x. e) | CaseBind -- ^ The x in case scrut of x { (y,z) -> ... } | CasePatBind -- ^ The y,z in case scrut of x { (y,z) -> ... } | LetBind -- ^ The x in (let x = rhs in e) -- | When we print a binder, we often want to print its type too. -- The @OutputableBndr@ class encapsulates this idea. class Outputable a => OutputableBndr a where pprBndr :: BindingSite -> a -> SDoc pprBndr _b x = ppr x pprPrefixOcc, pprInfixOcc :: a -> SDoc -- Print an occurrence of the name, suitable either in the -- prefix position of an application, thus (f a b) or ((+) x) -- or infix position, thus (a `f` b) or (x + y) bndrIsJoin_maybe :: a -> Maybe Int bndrIsJoin_maybe _ = Nothing -- When pretty-printing we sometimes want to find -- whether the binder is a join point. You might think -- we could have a function of type (a->Var), but Var -- isn't available yet, alas {- ************************************************************************ * * \subsection{Random printing helpers} * * ************************************************************************ -} -- We have 31-bit Chars and will simply use Show instances of Char and String. -- | Special combinator for showing character literals. pprHsChar :: Char -> SDoc pprHsChar c | c > '\x10ffff' = char '\\' <> text (show (fromIntegral (ord c) :: Word32)) | otherwise = text (show c) -- | Special combinator for showing string literals. pprHsString :: FastString -> SDoc pprHsString fs = vcat (map text (showMultiLineString (unpackFS fs))) -- | Special combinator for showing bytestring literals. pprHsBytes :: ByteString -> SDoc pprHsBytes bs = let escaped = concatMap escape $ BS.unpack bs in vcat (map text (showMultiLineString escaped)) <> char '#' where escape :: Word8 -> String escape w = let c = chr (fromIntegral w) in if isAscii c then [c] else '\\' : show w -- Postfix modifiers for unboxed literals. -- See Note [Printing of literals in Core] in `basicTypes/Literal.hs`. primCharSuffix, primFloatSuffix, primIntSuffix :: SDoc primDoubleSuffix, primWordSuffix, primInt64Suffix, primWord64Suffix :: SDoc primCharSuffix = char '#' primFloatSuffix = char '#' primIntSuffix = char '#' primDoubleSuffix = text "##" primWordSuffix = text "##" primInt64Suffix = text "L#" primWord64Suffix = text "L##" -- | Special combinator for showing unboxed literals. pprPrimChar :: Char -> SDoc pprPrimInt, pprPrimWord, pprPrimInt64, pprPrimWord64 :: Integer -> SDoc pprPrimChar c = pprHsChar c <> primCharSuffix pprPrimInt i = integer i <> primIntSuffix pprPrimWord w = word w <> primWordSuffix pprPrimInt64 i = integer i <> primInt64Suffix pprPrimWord64 w = word w <> primWord64Suffix --------------------- -- Put a name in parens if it's an operator pprPrefixVar :: Bool -> SDoc -> SDoc pprPrefixVar is_operator pp_v | is_operator = parens pp_v | otherwise = pp_v -- Put a name in backquotes if it's not an operator pprInfixVar :: Bool -> SDoc -> SDoc pprInfixVar is_operator pp_v | is_operator = pp_v | otherwise = char '`' <> pp_v <> char '`' --------------------- pprFastFilePath :: FastString -> SDoc pprFastFilePath path = text $ normalise $ unpackFS path {- ************************************************************************ * * \subsection{Other helper functions} * * ************************************************************************ -} pprWithCommas :: (a -> SDoc) -- ^ The pretty printing function to use -> [a] -- ^ The things to be pretty printed -> SDoc -- ^ 'SDoc' where the things have been pretty printed, -- comma-separated and finally packed into a paragraph. pprWithCommas pp xs = fsep (punctuate comma (map pp xs)) pprWithBars :: (a -> SDoc) -- ^ The pretty printing function to use -> [a] -- ^ The things to be pretty printed -> SDoc -- ^ 'SDoc' where the things have been pretty printed, -- bar-separated and finally packed into a paragraph. pprWithBars pp xs = fsep (intersperse vbar (map pp xs)) -- | Returns the separated concatenation of the pretty printed things. interppSP :: Outputable a => [a] -> SDoc interppSP xs = sep (map ppr xs) -- | Returns the comma-separated concatenation of the pretty printed things. interpp'SP :: Outputable a => [a] -> SDoc interpp'SP xs = sep (punctuate comma (map ppr xs)) -- | Returns the comma-separated concatenation of the quoted pretty printed things. -- -- > [x,y,z] ==> `x', `y', `z' pprQuotedList :: Outputable a => [a] -> SDoc pprQuotedList = quotedList . map ppr quotedList :: [SDoc] -> SDoc quotedList xs = fsep (punctuate comma (map quotes xs)) quotedListWithOr :: [SDoc] -> SDoc -- [x,y,z] ==> `x', `y' or `z' quotedListWithOr xs@(_:_:_) = quotedList (init xs) <+> text "or" <+> quotes (last xs) quotedListWithOr xs = quotedList xs quotedListWithNor :: [SDoc] -> SDoc -- [x,y,z] ==> `x', `y' nor `z' quotedListWithNor xs@(_:_:_) = quotedList (init xs) <+> text "nor" <+> quotes (last xs) quotedListWithNor xs = quotedList xs {- ************************************************************************ * * \subsection{Printing numbers verbally} * * ************************************************************************ -} intWithCommas :: Integral a => a -> SDoc -- Prints a big integer with commas, eg 345,821 intWithCommas n | n < 0 = char '-' <> intWithCommas (-n) | q == 0 = int (fromIntegral r) | otherwise = intWithCommas q <> comma <> zeroes <> int (fromIntegral r) where (q,r) = n `quotRem` 1000 zeroes | r >= 100 = empty | r >= 10 = char '0' | otherwise = text "00" -- | Converts an integer to a verbal index: -- -- > speakNth 1 = text "first" -- > speakNth 5 = text "fifth" -- > speakNth 21 = text "21st" speakNth :: Int -> SDoc speakNth 1 = text "first" speakNth 2 = text "second" speakNth 3 = text "third" speakNth 4 = text "fourth" speakNth 5 = text "fifth" speakNth 6 = text "sixth" speakNth n = hcat [ int n, text suffix ] where suffix | n <= 20 = "th" -- 11,12,13 are non-std | last_dig == 1 = "st" | last_dig == 2 = "nd" | last_dig == 3 = "rd" | otherwise = "th" last_dig = n `rem` 10 -- | Converts an integer to a verbal multiplicity: -- -- > speakN 0 = text "none" -- > speakN 5 = text "five" -- > speakN 10 = text "10" speakN :: Int -> SDoc speakN 0 = text "none" -- E.g. "he has none" speakN 1 = text "one" -- E.g. "he has one" speakN 2 = text "two" speakN 3 = text "three" speakN 4 = text "four" speakN 5 = text "five" speakN 6 = text "six" speakN n = int n -- | Converts an integer and object description to a statement about the -- multiplicity of those objects: -- -- > speakNOf 0 (text "melon") = text "no melons" -- > speakNOf 1 (text "melon") = text "one melon" -- > speakNOf 3 (text "melon") = text "three melons" speakNOf :: Int -> SDoc -> SDoc speakNOf 0 d = text "no" <+> d <> char 's' speakNOf 1 d = text "one" <+> d -- E.g. "one argument" speakNOf n d = speakN n <+> d <> char 's' -- E.g. "three arguments" -- | Determines the pluralisation suffix appropriate for the length of a list: -- -- > plural [] = char 's' -- > plural ["Hello"] = empty -- > plural ["Hello", "World"] = char 's' plural :: [a] -> SDoc plural [_] = empty -- a bit frightening, but there you are plural _ = char 's' -- | Determines the form of to be appropriate for the length of a list: -- -- > isOrAre [] = text "are" -- > isOrAre ["Hello"] = text "is" -- > isOrAre ["Hello", "World"] = text "are" isOrAre :: [a] -> SDoc isOrAre [_] = text "is" isOrAre _ = text "are" -- | Determines the form of to do appropriate for the length of a list: -- -- > doOrDoes [] = text "do" -- > doOrDoes ["Hello"] = text "does" -- > doOrDoes ["Hello", "World"] = text "do" doOrDoes :: [a] -> SDoc doOrDoes [_] = text "does" doOrDoes _ = text "do" {- ************************************************************************ * * \subsection{Error handling} * * ************************************************************************ -} callStackDoc :: HasCallStack => SDoc callStackDoc = hang (text "Call stack:") 4 (vcat $ map text $ lines (prettyCallStack callStack)) pprPanic :: HasCallStack => String -> SDoc -> a -- ^ Throw an exception saying "bug in GHC" pprPanic s doc = panicDoc s (doc $$ callStackDoc) pprSorry :: String -> SDoc -> a -- ^ Throw an exception saying "this isn't finished yet" pprSorry = sorryDoc pprPgmError :: String -> SDoc -> a -- ^ Throw an exception saying "bug in pgm being compiled" (used for unusual program errors) pprPgmError = pgmErrorDoc pprTraceDebug :: String -> SDoc -> a -> a pprTraceDebug str doc x | debugIsOn && hasPprDebug unsafeGlobalDynFlags = pprTrace str doc x | otherwise = x pprTrace :: String -> SDoc -> a -> a -- ^ If debug output is on, show some 'SDoc' on the screen pprTrace str doc x | hasNoDebugOutput unsafeGlobalDynFlags = x | otherwise = pprDebugAndThen unsafeGlobalDynFlags trace (text str) doc x pprTraceM :: Applicative f => String -> SDoc -> f () pprTraceM str doc = pprTrace str doc (pure ()) -- | @pprTraceIt desc x@ is equivalent to @pprTrace desc (ppr x) x@ pprTraceIt :: Outputable a => String -> a -> a pprTraceIt desc x = pprTrace desc (ppr x) x -- | @pprTraceException desc x action@ runs action, printing a message -- if it throws an exception. pprTraceException :: ExceptionMonad m => String -> SDoc -> m a -> m a pprTraceException heading doc = handleGhcException $ \exc -> liftIO $ do putStrLn $ showSDocDump unsafeGlobalDynFlags (sep [text heading, nest 2 doc]) throwGhcExceptionIO exc -- | If debug output is on, show some 'SDoc' on the screen along -- with a call stack when available. pprSTrace :: HasCallStack => SDoc -> a -> a pprSTrace doc = pprTrace "" (doc $$ callStackDoc) warnPprTrace :: Bool -> String -> Int -> SDoc -> a -> a -- ^ Just warn about an assertion failure, recording the given file and line number. -- Should typically be accessed with the WARN macros warnPprTrace _ _ _ _ x | not debugIsOn = x warnPprTrace _ _file _line _msg x | hasNoDebugOutput unsafeGlobalDynFlags = x warnPprTrace False _file _line _msg x = x warnPprTrace True file line msg x = pprDebugAndThen unsafeGlobalDynFlags trace heading msg x where heading = hsep [text "WARNING: file", text file <> comma, text "line", int line] -- | Panic with an assertation failure, recording the given file and -- line number. Should typically be accessed with the ASSERT family of macros assertPprPanic :: HasCallStack => String -> Int -> SDoc -> a assertPprPanic _file _line msg = pprPanic "ASSERT failed!" msg pprDebugAndThen :: DynFlags -> (String -> a) -> SDoc -> SDoc -> a pprDebugAndThen dflags cont heading pretty_msg = cont (showSDocDump dflags doc) where doc = sep [heading, nest 2 pretty_msg]