%
-% (c) The GRASP Project, Glasgow University, 1992-1996
+% (c) The GRASP Project, Glasgow University, 1992-1998
%
\section[Outputable]{Classes for pretty-printing}
``output.''
\begin{code}
-#include "HsVersions.h"
module Outputable (
- Outputable(..), -- class
+ Outputable(..), OutputableBndr(..), -- Class
+
+ BindingSite(..),
+
+ PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify,
+ getPprStyle, withPprStyle, withPprStyleDoc, pprDeeper,
+ codeStyle, userStyle, debugStyle, asmStyle,
+ ifPprDebug, unqualStyle,
+ mkErrStyle, defaultErrStyle,
+
+ SDoc, -- Abstract
+ docToSDoc,
+ interppSP, interpp'SP, pprQuotedList, pprWithCommas,
+ empty, nest,
+ text, char, ftext, ptext,
+ int, integer, float, double, rational,
+ parens, brackets, braces, quotes, doubleQuotes, angleBrackets,
+ semi, comma, colon, dcolon, space, equals, dot, arrow,
+ lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore,
+ (<>), (<+>), hcat, hsep,
+ ($$), ($+$), vcat,
+ sep, cat,
+ fsep, fcat,
+ hang, punctuate,
+ speakNth, speakNTimes,
+
+ printSDoc, printErrs, printDump,
+ printForC, printForAsm, printForUser,
+ pprCode, mkCodeStyle,
+ showSDoc, showSDocForUser, showSDocDebug,
+ showSDocUnqual, showsPrecSDoc,
+ pprHsChar, pprHsString,
- interppSP, interpp'SP,
- ifnotPprForUser,
- ifPprDebug,
- ifPprShowAll, ifnotPprShowAll,
- ifPprInterface
+
+ -- error handling
+ pprPanic, pprPanic#, pprError, pprTrace, assertPprPanic, warnPprTrace,
+ trace, panic, panic#, assertPanic
) where
-import Ubiq{-uitous-}
+#include "HsVersions.h"
+
+
+import {-# SOURCE #-} Module( ModuleName )
+import {-# SOURCE #-} OccName( OccName )
+
+import CmdLineOpts ( opt_PprStyle_Debug, opt_PprUserLength )
+import FastString
+import qualified Pretty
+import Pretty ( Doc, Mode(..) )
+import Panic
-import PprStyle ( PprStyle(..) )
-import Pretty
-import Util ( cmpPString )
+import DATA_WORD ( Word32 )
+
+import IO ( Handle, stderr, stdout, hFlush )
+import Char ( ord )
\end{code}
+
%************************************************************************
%* *
-\subsection[Outputable-class]{The @Outputable@ class}
+\subsection{The @PprStyle@ data type}
%* *
%************************************************************************
\begin{code}
-class Outputable a where
- ppr :: PprStyle -> a -> Pretty
+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.
+
+ | PprCode CodeStyle -- Print code; either C or assembler
+
+ | PprDebug -- Standard debugging output
+
+data CodeStyle = CStyle -- The format of labels differs for C and assembler
+ | AsmStyle
+
+data Depth = AllTheWay
+ | PartWay Int -- 0 => stop
+
+
+type PrintUnqualified = ModuleName -> OccName -> Bool
+ -- This function tells when it's ok to print
+ -- a (Global) name unqualified
+
+alwaysQualify,neverQualify :: PrintUnqualified
+alwaysQualify m n = False
+neverQualify m n = True
+
+defaultUserStyle = mkUserStyle alwaysQualify AllTheWay
+
+mkErrStyle :: PrintUnqualified -> PprStyle
+-- Style for printing error messages
+mkErrStyle print_unqual = mkUserStyle print_unqual (PartWay opt_PprUserLength)
+
+defaultErrStyle :: 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
+ | opt_PprStyle_Debug = mkUserStyle alwaysQualify AllTheWay
+ | otherwise = mkUserStyle alwaysQualify (PartWay opt_PprUserLength)
+
+mkUserStyle unqual depth | opt_PprStyle_Debug = PprDebug
+ | otherwise = PprUser unqual depth
\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}
--- the ppSep in the ppInterleave puts in the spaces
--- Death to ppSep! (WDP 94/11)
+type SDoc = PprStyle -> Doc
-interppSP :: Outputable a => PprStyle -> [a] -> Pretty
-interppSP sty xs = ppIntersperse ppSP (map (ppr sty) xs)
+withPprStyle :: PprStyle -> SDoc -> SDoc
+withPprStyle sty d sty' = d sty
-interpp'SP :: Outputable a => PprStyle -> [a] -> Pretty
-interpp'SP sty xs
- = ppIntersperse sep (map (ppr sty) xs)
- where
- sep = ppBeside ppComma ppSP
-
-#ifdef USE_ATTACK_PRAGMAS
-{-# SPECIALIZE interppSP :: PprStyle -> [Id] -> Pretty #-}
-{-# SPECIALIZE interppSP :: PprStyle -> [TyVar] -> Pretty #-}
-
-{-# SPECIALIZE interpp'SP :: PprStyle -> [(Id, Id)] -> Pretty #-}
-{-# SPECIALIZE interpp'SP :: PprStyle -> [Id] -> Pretty #-}
-{-# SPECIALIZE interpp'SP :: PprStyle -> [TyVarTemplate] -> Pretty #-}
-{-# SPECIALIZE interpp'SP :: PprStyle -> [TyVar] -> Pretty #-}
-{-# SPECIALIZE interpp'SP :: PprStyle -> [Type] -> Pretty #-}
-#endif
+withPprStyleDoc :: PprStyle -> SDoc -> Doc
+withPprStyleDoc sty d = d sty
+
+pprDeeper :: SDoc -> SDoc
+pprDeeper d (PprUser unqual (PartWay 0)) = Pretty.text "..."
+pprDeeper d (PprUser unqual (PartWay n)) = d (PprUser unqual (PartWay (n-1)))
+pprDeeper d other_sty = d other_sty
+
+getPprStyle :: (PprStyle -> SDoc) -> SDoc
+getPprStyle df sty = df sty sty
\end{code}
\begin{code}
-ifPprDebug sty p = case sty of PprDebug -> p ; _ -> ppNil
-ifPprShowAll sty p = case sty of PprShowAll -> p ; _ -> ppNil
-ifPprInterface sty p = case sty of PprInterface -> p ; _ -> ppNil
+unqualStyle :: PprStyle -> PrintUnqualified
+unqualStyle (PprUser unqual _) m n = unqual m n
+unqualStyle other m n = False
+
+codeStyle :: PprStyle -> Bool
+codeStyle (PprCode _) = True
+codeStyle _ = False
+
+asmStyle :: PprStyle -> Bool
+asmStyle (PprCode AsmStyle) = True
+asmStyle other = False
+
+debugStyle :: PprStyle -> Bool
+debugStyle PprDebug = True
+debugStyle other = False
-ifnotPprForUser sty p = case sty of PprForUser -> ppNil ; _ -> p
-ifnotPprShowAll sty p = case sty of PprShowAll -> ppNil ; _ -> p
+userStyle :: PprStyle -> Bool
+userStyle (PprUser _ _) = True
+userStyle other = False
+
+ifPprDebug :: SDoc -> SDoc -- Empty for non-debug style
+ifPprDebug d sty@PprDebug = d sty
+ifPprDebug d sty = Pretty.empty
+\end{code}
+
+\begin{code}
+-- Unused [7/02 sof]
+printSDoc :: SDoc -> PprStyle -> IO ()
+printSDoc d sty = do
+ Pretty.printDoc PageMode stdout (d sty)
+ hFlush stdout
+
+-- I'm not sure whether the direct-IO approach of Pretty.printDoc
+-- above is better or worse than the put-big-string approach here
+printErrs :: Doc -> IO ()
+printErrs doc = do Pretty.printDoc PageMode stderr doc
+ hFlush stderr
+
+printDump :: SDoc -> IO ()
+printDump doc = do
+ Pretty.printDoc PageMode stdout (better_doc defaultUserStyle)
+ hFlush stdout
+ where
+ better_doc = doc $$ text ""
+ -- We used to always print in debug style, but I want
+ -- to try the effect of a more user-ish style (unless you
+ -- say -dppr-debug)
+
+printForUser :: Handle -> PrintUnqualified -> SDoc -> IO ()
+printForUser handle unqual doc
+ = Pretty.printDoc PageMode handle (doc (mkUserStyle unqual AllTheWay))
+
+-- printForC, printForAsm do what they sound like
+printForC :: Handle -> SDoc -> IO ()
+printForC handle doc = Pretty.printDoc LeftMode handle (doc (PprCode CStyle))
+
+printForAsm :: Handle -> SDoc -> IO ()
+printForAsm handle doc = Pretty.printDoc LeftMode handle (doc (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 :: SDoc -> String
+showSDoc d = show (d defaultUserStyle)
+
+showSDocForUser :: PrintUnqualified -> SDoc -> String
+showSDocForUser unqual doc = show (doc (mkUserStyle unqual AllTheWay))
+
+showSDocUnqual :: SDoc -> String
+-- Only used in the gruesome HsExpr.isOperator
+showSDocUnqual d = show (d (mkUserStyle neverQualify AllTheWay))
+
+showsPrecSDoc :: Int -> SDoc -> ShowS
+showsPrecSDoc p d = showsPrec p (d defaultUserStyle)
+
+showSDocDebug :: SDoc -> String
+showSDocDebug d = show (d PprDebug)
+\end{code}
+
+\begin{code}
+docToSDoc :: Doc -> SDoc
+docToSDoc d = \_ -> d
+
+empty sty = Pretty.empty
+text s sty = Pretty.text s
+char c sty = Pretty.char c
+ftext s sty = Pretty.ftext s
+ptext s sty = Pretty.ptext s
+int n sty = Pretty.int n
+integer n sty = Pretty.integer n
+float n sty = Pretty.float n
+double n sty = Pretty.double n
+rational n sty = Pretty.rational n
+
+parens d sty = Pretty.parens (d sty)
+braces d sty = Pretty.braces (d sty)
+brackets d sty = Pretty.brackets (d sty)
+doubleQuotes d sty = Pretty.doubleQuotes (d sty)
+angleBrackets d = char '<' <> d <> char '>'
+
+-- quotes encloses something in single quotes...
+-- but it omits them if the thing ends in a single quote
+-- so that we don't get `foo''. Instead we just have foo'.
+quotes d sty = case show pp_d of
+ ('\'' : _) -> pp_d
+ other -> Pretty.quotes pp_d
+ where
+ pp_d = d sty
+
+semi sty = Pretty.semi
+comma sty = Pretty.comma
+colon sty = Pretty.colon
+equals sty = Pretty.equals
+space sty = Pretty.space
+lparen sty = Pretty.lparen
+rparen sty = Pretty.rparen
+lbrack sty = Pretty.lbrack
+rbrack sty = Pretty.rbrack
+lbrace sty = Pretty.lbrace
+rbrace sty = Pretty.rbrace
+dcolon sty = Pretty.ptext SLIT("::")
+arrow sty = Pretty.ptext SLIT("->")
+underscore = char '_'
+dot = char '.'
+
+nest n d sty = Pretty.nest n (d sty)
+(<>) d1 d2 sty = (Pretty.<>) (d1 sty) (d2 sty)
+(<+>) d1 d2 sty = (Pretty.<+>) (d1 sty) (d2 sty)
+($$) d1 d2 sty = (Pretty.$$) (d1 sty) (d2 sty)
+($+$) d1 d2 sty = (Pretty.$+$) (d1 sty) (d2 sty)
+
+hcat ds sty = Pretty.hcat [d sty | d <- ds]
+hsep ds sty = Pretty.hsep [d sty | d <- ds]
+vcat ds sty = Pretty.vcat [d sty | d <- ds]
+sep ds sty = Pretty.sep [d sty | d <- ds]
+cat ds sty = Pretty.cat [d sty | d <- ds]
+fsep ds sty = Pretty.fsep [d sty | d <- ds]
+fcat ds sty = Pretty.fcat [d sty | d <- ds]
+
+hang d1 n d2 sty = Pretty.hang (d1 sty) n (d2 sty)
+
+punctuate :: SDoc -> [SDoc] -> [SDoc]
+punctuate p [] = []
+punctuate p (d:ds) = go d ds
+ where
+ go d [] = [d]
+ go d (e:es) = (d <> p) : go e es
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection[Outputable-class]{The @Outputable@ class}
+%* *
+%************************************************************************
+
+\begin{code}
+class Outputable a where
+ ppr :: a -> SDoc
\end{code}
\begin{code}
instance Outputable Bool where
- ppr sty True = ppPStr SLIT("True")
- ppr sty False = ppPStr SLIT("False")
+ ppr True = ptext SLIT("True")
+ ppr False = ptext SLIT("False")
+
+instance Outputable Int where
+ ppr n = int n
+
+instance Outputable () where
+ ppr _ = text "()"
instance (Outputable a) => Outputable [a] where
- ppr sty xs =
- ppBesides [ ppLbrack, ppInterleave ppComma (map (ppr sty) xs), ppRbrack ]
+ ppr xs = brackets (fsep (punctuate comma (map ppr xs)))
instance (Outputable a, Outputable b) => Outputable (a, b) where
- ppr sty (x,y) =
- ppHang (ppBesides [ppLparen, ppr sty x, ppComma]) 4 (ppBeside (ppr sty y) ppRparen)
+ 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
-- ToDo: may not be used
instance (Outputable a, Outputable b, Outputable c) => Outputable (a, b, c) where
- ppr sty (x,y,z) =
- ppSep [ ppBesides [ppLparen, ppr sty x, ppComma],
- ppBeside (ppr sty y) ppComma,
- ppBeside (ppr sty z) ppRparen ]
+ 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 (x,y,z,w) =
+ parens (sep [ppr x <> comma,
+ ppr y <> comma,
+ ppr z <> comma,
+ ppr w])
+
+instance Outputable FastString where
+ ppr fs = text (unpackFS fs) -- Prints an unadorned string,
+ -- no double quotes or anything
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{The @OutputableBndr@ class}
+%* *
+%************************************************************************
+
+When we print a binder, we often want to print its type too.
+The @OutputableBndr@ class encapsulates this idea.
+
+@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.
+
+\begin{code}
+data BindingSite = LambdaBind | CaseBind | LetBind
+
+class Outputable a => OutputableBndr a where
+ pprBndr :: BindingSite -> a -> SDoc
+ pprBndr b x = ppr x
+\end{code}
+
+
+
+%************************************************************************
+%* *
+\subsection{Random printing helpers}
+%* *
+%************************************************************************
+
+\begin{code}
+-- We have 31-bit Chars and will simply use Show instances
+-- of Char and String.
+
+pprHsChar :: Char -> SDoc
+pprHsChar c | c > '\x10ffff' = char '\\' <> text (show (fromIntegral (ord c) :: Word32))
+ | otherwise = text (show c)
+
+pprHsString :: FastString -> SDoc
+pprHsString fs = text (show (unpackFS fs))
+
+instance Show FastString where
+ showsPrec p fs = showsPrecSDoc p (ppr fs)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Other helper functions}
+%* *
+%************************************************************************
+
+\begin{code}
+pprWithCommas :: (a -> SDoc) -> [a] -> SDoc
+pprWithCommas pp xs = fsep (punctuate comma (map pp xs))
+
+interppSP :: Outputable a => [a] -> SDoc
+interppSP xs = sep (map ppr xs)
+
+interpp'SP :: Outputable a => [a] -> SDoc
+interpp'SP xs = sep (punctuate comma (map ppr xs))
+
+pprQuotedList :: Outputable a => [a] -> SDoc
+-- [x,y,z] ==> `x', `y', `z'
+pprQuotedList xs = hsep (punctuate comma (map (quotes . ppr) xs))
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Printing numbers verbally}
+%* *
+%************************************************************************
+
+@speakNth@ converts an integer to a verbal index; eg 1 maps to
+``first'' etc.
+
+\begin{code}
+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
+\end{code}
+
+\begin{code}
+speakNTimes :: Int {- >=1 -} -> SDoc
+speakNTimes t | t == 1 = ptext SLIT("once")
+ | t == 2 = ptext SLIT("twice")
+ | otherwise = int t <+> ptext SLIT("times")
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Error handling}
+%* *
+%************************************************************************
+
+\begin{code}
+pprPanic :: String -> SDoc -> a
+pprError :: String -> SDoc -> a
+pprTrace :: String -> SDoc -> a -> a
+pprPanic = pprAndThen panic
+pprError = pprAndThen error
+pprTrace = pprAndThen trace
+
+pprPanic# heading pretty_msg = panic# (show (doc PprDebug))
+ where
+ doc = text heading <+> pretty_msg
+
+pprAndThen :: (String -> a) -> String -> SDoc -> a
+pprAndThen cont heading pretty_msg = cont (show (doc PprDebug))
+ where
+ doc = sep [text heading, nest 4 pretty_msg]
+
+assertPprPanic :: String -> Int -> SDoc -> a
+assertPprPanic file line msg
+ = panic (show (doc PprDebug))
+ where
+ doc = sep [hsep[text "ASSERT failed! file",
+ text file,
+ text "line", int line],
+ msg]
+
+warnPprTrace :: Bool -> String -> Int -> SDoc -> a -> a
+warnPprTrace False file line msg x = x
+warnPprTrace True file line msg x
+ = trace (show (doc PprDebug)) x
+ where
+ doc = sep [hsep [text "WARNING: file", text file, text "line", int line],
+ msg]
\end{code}