% % (c) The University of Glasgow 2006-2012 % (c) The GRASP Project, Glasgow University, 1992-1998 % \begin{code} -- | 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, empty, nest, char, text, ftext, ptext, ztext, int, intWithCommas, integer, float, double, rational, parens, cparen, brackets, braces, quotes, quote, doubleQuotes, angleBrackets, paBrackets, semi, comma, colon, dcolon, space, equals, dot, arrow, darrow, lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore, blankLine, (<>), (<+>), hcat, hsep, ($$), ($+$), vcat, sep, cat, fsep, fcat, hang, punctuate, ppWhen, ppUnless, speakNth, speakNTimes, speakN, speakNOf, plural, isOrAre, coloured, PprColour, colType, colCoerc, colDataCon, colBinder, bold, keyword, -- * Converting 'SDoc' into strings and outputing it printForC, printForAsm, printForUser, printForUserPartWay, pprCode, mkCodeStyle, showSDoc, showSDocOneLine, showSDocForUser, showSDocDebug, showSDocDump, showSDocDumpOneLine, showPpr, showSDocUnqual, renderWithStyle, pprInfixVar, pprPrefixVar, pprHsChar, pprHsString, pprHsBytes, pprFastFilePath, -- * Controlling the style in which output is printed BindingSite(..), PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify, neverQualify, QualifyName(..), sdocWithDynFlags, sdocWithPlatform, getPprStyle, withPprStyle, withPprStyleDoc, pprDeeper, pprDeeperList, pprSetDepth, codeStyle, userStyle, debugStyle, dumpStyle, asmStyle, ifPprDebug, qualName, qualModule, mkErrStyle, defaultErrStyle, defaultDumpStyle, defaultUserStyle, mkUserStyle, cmdlineParserStyle, Depth(..), -- * Error handling and debugging utilities pprPanic, pprSorry, assertPprPanic, pprPanicFastInt, pprPgmError, pprTrace, warnPprTrace, trace, pgmError, panic, sorry, panicFastInt, assertPanic, pprDebugAndThen, ) where import {-# SOURCE #-} DynFlags( DynFlags, targetPlatform, pprUserLength, pprCols, useUnicodeQuotes, unsafeGlobalDynFlags ) import {-# SOURCE #-} Module( Module, ModuleName, moduleName ) import {-# SOURCE #-} Name( Name, nameModule ) import {-# SOURCE #-} StaticFlags( opt_PprStyle_Debug, opt_NoDebugOutput ) import FastString import FastTypes import qualified Pretty import Util import Platform import Pretty ( Doc, Mode(..) ) import Panic 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.Word import System.IO ( Handle ) import System.FilePath import Text.Printf import GHC.Fingerprint import GHC.Show ( showMultiLineString ) \end{code} %************************************************************************ %* * \subsection{The @PprStyle@ data type} %* * %************************************************************************ \begin{code} data PprStyle = PprUser PrintUnqualified Depth -- 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. | PprCode CodeStyle -- Print code; either C or assembler | PprDump -- For -ddump-foo; less verbose than PprDebug. -- Does not assume tidied code: non-external names -- are printed with uniques. | PprDebug -- Full debugging output data CodeStyle = CStyle -- The format of labels differs for C and assembler | AsmStyle data Depth = AllTheWay | PartWay Int -- 0 => stop -- ----------------------------------------------------------------------------- -- 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 pair of functions that gets passed around -- when rendering 'SDoc'. -- | given an /original/ name, this function tells you which module -- name it should be qualified with when printing for the user, if -- any. For example, given @Control.Exception.catch@, which is in scope -- as @Exception.catch@, this fuction will return @Just "Exception"@. -- Note that the return value is a ModuleName, not a Module, because -- in source code, names are qualified by ModuleNames. type QueryQualifyName = Name -> QualifyName -- See Note [Printing original names] in HscTypes data QualifyName -- given P:M.T = NameUnqual -- refer to it as "T" | NameQual ModuleName -- refer to it as "X.T" for the supplied X | NameNotInScope1 -- it is 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 is 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" -- | For a given module, we need to know whether to print it with -- a package name to disambiguate it. type QueryQualifyModule = Module -> Bool type PrintUnqualified = (QueryQualifyName, QueryQualifyModule) alwaysQualifyNames :: QueryQualifyName alwaysQualifyNames n = NameQual (moduleName (nameModule n)) neverQualifyNames :: QueryQualifyName neverQualifyNames _ = NameUnqual alwaysQualifyModules :: QueryQualifyModule alwaysQualifyModules _ = True neverQualifyModules :: QueryQualifyModule neverQualifyModules _ = False alwaysQualify, neverQualify :: PrintUnqualified alwaysQualify = (alwaysQualifyNames, alwaysQualifyModules) neverQualify = (neverQualifyNames, neverQualifyModules) defaultUserStyle, defaultDumpStyle :: PprStyle defaultUserStyle = mkUserStyle alwaysQualify AllTheWay defaultDumpStyle | opt_PprStyle_Debug = PprDebug | otherwise = PprDump -- | Style for printing error messages mkErrStyle :: DynFlags -> PrintUnqualified -> PprStyle mkErrStyle dflags qual = mkUserStyle qual (PartWay (pprUserLength dflags)) defaultErrStyle :: DynFlags -> PprStyle -- Default style for error messages -- 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 defaultErrStyle dflags = mkUserStyle alwaysQualify depth where depth = if opt_PprStyle_Debug then AllTheWay else PartWay (pprUserLength dflags) mkUserStyle :: PrintUnqualified -> Depth -> PprStyle mkUserStyle unqual depth | opt_PprStyle_Debug = PprDebug | otherwise = PprUser unqual depth cmdlineParserStyle :: PprStyle cmdlineParserStyle = PprUser alwaysQualify AllTheWay \end{code} 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} %* * %************************************************************************ \begin{code} newtype SDoc = SDoc { runSDoc :: SDocContext -> Doc } data SDocContext = SDC { sdocStyle :: !PprStyle , sdocLastColour :: !PprColour -- ^ The most recently used colour. This allows nesting colours. , sdocDynFlags :: !DynFlags } initSDocContext :: DynFlags -> PprStyle -> SDocContext initSDocContext dflags sty = SDC { sdocStyle = sty , sdocLastColour = colReset , sdocDynFlags = dflags } withPprStyle :: PprStyle -> SDoc -> SDoc withPprStyle sty d = SDoc $ \ctxt -> runSDoc d ctxt{sdocStyle=sty} 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)} -> runSDoc d ctx{sdocStyle = PprUser q (PartWay (n-1))} _ -> runSDoc d ctx pprDeeperList :: ([SDoc] -> SDoc) -> [SDoc] -> SDoc -- Truncate a list that list that is longer than the current depth pprDeeperList f ds | null ds = f [] | otherwise = SDoc work where work ctx@SDC{sdocStyle=PprUser q (PartWay n)} | n==0 = Pretty.text "..." | otherwise = runSDoc (f (go 0 ds)) ctx{sdocStyle = PprUser q (PartWay (n-1))} 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 _} -> runSDoc doc ctx{sdocStyle = PprUser q depth} _ -> 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) \end{code} \begin{code} qualName :: PprStyle -> QueryQualifyName qualName (PprUser (qual_name,_) _) n = qual_name n qualName _other n = NameQual (moduleName (nameModule n)) qualModule :: PprStyle -> QueryQualifyModule qualModule (PprUser (_,qual_mod) _) m = qual_mod m qualModule _other _m = True 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 ifPprDebug :: SDoc -> SDoc -- Empty for non-debug style ifPprDebug d = SDoc $ \ctx -> case ctx of SDC{sdocStyle=PprDebug} -> runSDoc d ctx _ -> Pretty.empty \end{code} \begin{code} printForUser :: DynFlags -> Handle -> PrintUnqualified -> SDoc -> IO () printForUser dflags handle unqual doc = Pretty.printDoc PageMode (pprCols dflags) handle (runSDoc doc (initSDocContext dflags (mkUserStyle unqual AllTheWay))) printForUserPartWay :: DynFlags -> Handle -> Int -> PrintUnqualified -> SDoc -> IO () printForUserPartWay dflags handle d unqual doc = Pretty.printDoc PageMode (pprCols dflags) handle (runSDoc doc (initSDocContext dflags (mkUserStyle unqual (PartWay d)))) -- printForC, printForAsm do what they sound like printForC :: DynFlags -> Handle -> SDoc -> IO () printForC dflags handle doc = Pretty.printDoc LeftMode (pprCols dflags) handle (runSDoc doc (initSDocContext dflags (PprCode CStyle))) printForAsm :: DynFlags -> Handle -> SDoc -> IO () printForAsm dflags handle doc = Pretty.printDoc LeftMode (pprCols dflags) handle (runSDoc doc (initSDocContext dflags (PprCode AsmStyle))) 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 d = Pretty.showDocWith PageMode (runSDoc d (initSDocContext dflags defaultUserStyle)) renderWithStyle :: DynFlags -> SDoc -> PprStyle -> String renderWithStyle dflags sdoc sty = Pretty.render (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 = Pretty.showDocWith PageMode (runSDoc d (initSDocContext dflags defaultUserStyle)) showSDocForUser :: DynFlags -> PrintUnqualified -> SDoc -> String showSDocForUser dflags unqual doc = show (runSDoc doc (initSDocContext dflags (mkUserStyle unqual AllTheWay))) showSDocUnqual :: DynFlags -> SDoc -> String -- Only used in the gruesome isOperator showSDocUnqual dflags d = show (runSDoc d (initSDocContext dflags (mkUserStyle neverQualify AllTheWay))) showSDocDump :: DynFlags -> SDoc -> String showSDocDump dflags d = Pretty.showDocWith PageMode (runSDoc d (initSDocContext dflags defaultDumpStyle)) showSDocDumpOneLine :: DynFlags -> SDoc -> String showSDocDumpOneLine dflags d = Pretty.showDocWith OneLineMode (runSDoc d (initSDocContext dflags PprDump)) showSDocDebug :: DynFlags -> SDoc -> String showSDocDebug dflags d = show (runSDoc d (initSDocContext dflags PprDebug)) showPpr :: Outputable a => DynFlags -> a -> String showPpr dflags = showSDoc dflags . ppr \end{code} \begin{code} 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 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 parens, braces, brackets, quotes, quote, paBrackets, 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 '>' paBrackets d = ptext (sLit "[:") <> d <> ptext (sLit ":]") cparen :: Bool -> SDoc -> SDoc cparen b d = SDoc $ Pretty.cparen 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 useUnicodeQuotes 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, arrow, underscore, dot :: SDoc darrow, lparen, rparen, lbrack, rbrack, lbrace, rbrace, blankLine :: SDoc blankLine = docToSDoc $ Pretty.ptext (sLit "") dcolon = docToSDoc $ Pretty.ptext (sLit "::") arrow = docToSDoc $ Pretty.ptext (sLit "->") darrow = docToSDoc $ Pretty.ptext (sLit "=>") semi = docToSDoc $ Pretty.semi comma = docToSDoc $ Pretty.comma colon = docToSDoc $ Pretty.colon equals = docToSDoc $ Pretty.equals space = docToSDoc $ Pretty.space underscore = char '_' dot = 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 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) 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 -- | A colour\/style for use with 'coloured'. newtype PprColour = PprColour String -- Colours colType :: PprColour colType = PprColour "\27[34m" colBold :: PprColour colBold = PprColour "\27[;1m" colCoerc :: PprColour colCoerc = PprColour "\27[34m" colDataCon :: PprColour colDataCon = PprColour "\27[31m" colBinder :: PprColour colBinder = PprColour "\27[32m" colReset :: PprColour colReset = PprColour "\27[0m" -- | Apply the given colour\/style for the argument. -- -- Only takes effect if colours are enabled. coloured :: PprColour -> SDoc -> SDoc -- TODO: coloured _ sdoc ctxt | coloursDisabled = sdoc ctxt coloured col@(PprColour c) sdoc = SDoc $ \ctx@SDC{ sdocLastColour = PprColour lc } -> let ctx' = ctx{ sdocLastColour = col } in Pretty.zeroWidthText c Pretty.<> runSDoc sdoc ctx' Pretty.<> Pretty.zeroWidthText lc bold :: SDoc -> SDoc bold = coloured colBold keyword :: SDoc -> SDoc keyword = bold \end{code} %************************************************************************ %* * \subsection[Outputable-class]{The @Outputable@ class} %* * %************************************************************************ \begin{code} -- | 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 \end{code} \begin{code} instance Outputable Char where ppr c = text [c] instance Outputable Bool where ppr True = ptext (sLit "True") ppr False = ptext (sLit "False") 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 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 = ptext (sLit "Nothing") ppr (Just x) = ptext (sLit "Just") <+> ppr x instance (Outputable a, Outputable b) => Outputable (Either a b) where ppr (Left x) = ptext (sLit "Left") <+> ppr x ppr (Right y) = ptext (sLit "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) \end{code} %************************************************************************ %* * \subsection{The @OutputableBndr@ class} %* * %************************************************************************ \begin{code} -- | '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. data BindingSite = LambdaBind | CaseBind | LetBind -- | 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) \end{code} %************************************************************************ %* * \subsection{Random printing helpers} %* * %************************************************************************ \begin{code} -- 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 string 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 --------------------- -- 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 \end{code} %************************************************************************ %* * \subsection{Other helper functions} %* * %************************************************************************ \begin{code} 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)) -- | 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 = hsep (punctuate comma (map quotes xs)) quotedListWithOr :: [SDoc] -> SDoc -- [x,y,z] ==> `x', `y' or `z' quotedListWithOr xs@(_:_:_) = quotedList (init xs) <+> ptext (sLit "or") <+> quotes (last xs) quotedListWithOr xs = quotedList xs \end{code} %************************************************************************ %* * \subsection{Printing numbers verbally} %* * %************************************************************************ \begin{code} 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 = ptext (sLit "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 = ptext (sLit "first") speakNth 2 = ptext (sLit "second") speakNth 3 = ptext (sLit "third") speakNth 4 = ptext (sLit "fourth") speakNth 5 = ptext (sLit "fifth") speakNth 6 = ptext (sLit "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 = ptext (sLit "none") -- E.g. "he has none" speakN 1 = ptext (sLit "one") -- E.g. "he has one" speakN 2 = ptext (sLit "two") speakN 3 = ptext (sLit "three") speakN 4 = ptext (sLit "four") speakN 5 = ptext (sLit "five") speakN 6 = ptext (sLit "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 = ptext (sLit "no") <+> d <> char 's' speakNOf 1 d = ptext (sLit "one") <+> d -- E.g. "one argument" speakNOf n d = speakN n <+> d <> char 's' -- E.g. "three arguments" -- | Converts a strictly positive integer into a number of times: -- -- > speakNTimes 1 = text "once" -- > speakNTimes 2 = text "twice" -- > speakNTimes 4 = text "4 times" speakNTimes :: Int {- >=1 -} -> SDoc speakNTimes t | t == 1 = ptext (sLit "once") | t == 2 = ptext (sLit "twice") | otherwise = speakN t <+> ptext (sLit "times") -- | 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 [] = ptext (sLit "are") -- > isOrAre ["Hello"] = ptext (sLit "is") -- > isOrAre ["Hello", "World"] = ptext (sLit "are") isOrAre :: [a] -> SDoc isOrAre [_] = ptext (sLit "is") isOrAre _ = ptext (sLit "are") \end{code} %************************************************************************ %* * \subsection{Error handling} %* * %************************************************************************ \begin{code} pprPanic :: String -> SDoc -> a -- ^ Throw an exception saying "bug in GHC" pprPanic = panicDoc 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 pprTrace :: String -> SDoc -> a -> a -- ^ If debug output is on, show some 'SDoc' on the screen pprTrace str doc x | opt_NoDebugOutput = x | otherwise = pprDebugAndThen unsafeGlobalDynFlags trace str doc x pprPanicFastInt :: String -> SDoc -> FastInt -- ^ Specialization of pprPanic that can be safely used with 'FastInt' pprPanicFastInt heading pretty_msg = panicDocFastInt heading pretty_msg 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 | opt_NoDebugOutput = x warnPprTrace False _file _line _msg x = x warnPprTrace True file line msg x = pprDebugAndThen unsafeGlobalDynFlags trace str msg x where str = showSDoc unsafeGlobalDynFlags (hsep [text "WARNING: file", text file <> comma, text "line", int line]) assertPprPanic :: String -> Int -> SDoc -> a -- ^ Panic with an assertation failure, recording the given file and line number. -- Should typically be accessed with the ASSERT family of macros assertPprPanic file line msg = pprPanic "ASSERT failed!" doc where doc = sep [ hsep [ text "file", text file , text "line", int line ] , msg ] pprDebugAndThen :: DynFlags -> (String -> a) -> String -> SDoc -> a pprDebugAndThen dflags cont heading pretty_msg = cont (showSDocDebug dflags doc) where doc = sep [text heading, nest 4 pretty_msg] \end{code}