% (c) The GRASP Project, Glasgow University, 1992-1998
%
-Outputable: defines classes for pretty-printing and forcing, both
-forms of ``output.''
-
\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 (
- Outputable(..), OutputableBndr(..), -- Class
-
- BindingSite(..),
-
- PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify,
- getPprStyle, withPprStyle, withPprStyleDoc,
- pprDeeper, pprDeeperList, pprSetDepth,
- codeStyle, userStyle, debugStyle, dumpStyle, asmStyle,
- ifPprDebug, qualName, qualModule,
- mkErrStyle, defaultErrStyle, defaultDumpStyle, defaultUserStyle,
+ -- * Type classes
+ Outputable(..), OutputableBndr(..),
- SDoc, -- Abstract
+ -- * Pretty printing combinators
+ SDoc,
docToSDoc,
- interppSP, interpp'SP, pprQuotedList, pprWithCommas,
+ interppSP, interpp'SP, pprQuotedList, pprWithCommas, quotedListWithOr,
empty, nest,
- text, char, ftext, ptext,
+ char,
+ text, ftext, ptext,
int, integer, float, double, rational,
parens, cparen, brackets, braces, quotes, doubleQuotes, angleBrackets,
- semi, comma, colon, dcolon, space, equals, dot, arrow,
+ semi, comma, colon, dcolon, space, equals, dot, arrow, darrow,
lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore,
+ blankLine,
(<>), (<+>), hcat, hsep,
- ($$), ($+$), vcat,
+ ($$), ($+$), vcat,
sep, cat,
fsep, fcat,
- hang, punctuate,
+ hang, punctuate, ppWhen, ppUnless,
speakNth, speakNTimes, speakN, speakNOf, plural,
- printSDoc, printErrs, printDump,
- printForC, printForAsm, printForUser,
+ -- * Converting 'SDoc' into strings and outputing it
+ printSDoc, printErrs, printOutput, hPrintDump, printDump,
+ printForC, printForAsm, printForUser, printForUserPartWay,
pprCode, mkCodeStyle,
- showSDoc, showSDocForUser, showSDocDebug, showSDocDump,
+ showSDoc, showSDocOneLine,
+ showSDocForUser, showSDocDebug, showSDocDump, showSDocDumpOneLine,
+ showPpr,
showSDocUnqual, showsPrecSDoc,
- pprHsChar, pprHsString,
- -- error handling
- pprPanic, assertPprPanic, pprPanic#, pprPgmError,
- pprTrace, warnPprTrace,
- trace, pgmError, panic, panic#, assertPanic
- ) where
+ pprInfixVar, pprPrefixVar,
+ pprHsChar, pprHsString, pprHsInfix, pprHsVar,
+ pprFastFilePath,
-#include "HsVersions.h"
+ -- * Controlling the style in which output is printed
+ BindingSite(..),
+ PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify, neverQualify,
+ QualifyName(..),
+ 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, assertPprPanic, pprPanicFastInt, pprPgmError,
+ pprTrace, warnPprTrace,
+ trace, pgmError, panic, panicFastInt, assertPanic
+ ) where
-import {-# SOURCE #-} Module( Module, modulePackageId,
- ModuleName, moduleName )
+import {-# SOURCE #-} Module( Module, ModuleName, moduleName )
import {-# SOURCE #-} OccName( OccName )
-import StaticFlags ( opt_PprStyle_Debug, opt_PprUserLength )
-import PackageConfig ( PackageId, packageIdString )
-import FastString
+import StaticFlags
+import FastString
+import FastTypes
import qualified Pretty
import Pretty ( Doc, Mode(..) )
import Panic
-import Data.Word ( Word32 )
+import Data.Char
+import Data.Word
import System.IO ( Handle, stderr, stdout, hFlush )
-import Data.Char ( ord )
+import System.FilePath
\end{code}
-- 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 QualifyName = Module -> OccName -> Maybe ModuleName
+type QueryQualifyName = Module -> OccName -> 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, and if so which package name should
--- we use.
-type QualifyModule = Module -> Maybe PackageId
+-- a package name to disambiguate it.
+type QueryQualifyModule = Module -> Bool
-type PrintUnqualified = (QualifyName, QualifyModule)
+type PrintUnqualified = (QueryQualifyName, QueryQualifyModule)
-alwaysQualifyNames :: QualifyName
-alwaysQualifyNames m n = Just (moduleName m)
+alwaysQualifyNames :: QueryQualifyName
+alwaysQualifyNames m _ = NameQual (moduleName m)
-neverQualifyNames :: QualifyName
-neverQualifyNames m n = Nothing
+neverQualifyNames :: QueryQualifyName
+neverQualifyNames _ _ = NameUnqual
-alwaysQualifyModules :: QualifyModule
-alwaysQualifyModules m = Just (modulePackageId m)
+alwaysQualifyModules :: QueryQualifyModule
+alwaysQualifyModules _ = True
-neverQualifyModules :: QualifyModule
-neverQualifyModules m = Nothing
+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
| opt_PprStyle_Debug = mkUserStyle alwaysQualify AllTheWay
| otherwise = mkUserStyle alwaysQualify (PartWay opt_PprUserLength)
+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
type SDoc = PprStyle -> Doc
withPprStyle :: PprStyle -> SDoc -> SDoc
-withPprStyle sty d sty' = d sty
+withPprStyle sty d _sty' = d sty
withPprStyleDoc :: PprStyle -> SDoc -> Doc
withPprStyleDoc sty d = d sty
pprDeeper :: SDoc -> SDoc
-pprDeeper d (PprUser q (PartWay 0)) = Pretty.text "..."
+pprDeeper _ (PprUser _ (PartWay 0)) = Pretty.text "..."
pprDeeper d (PprUser q (PartWay n)) = d (PprUser q (PartWay (n-1)))
pprDeeper d other_sty = d other_sty
| n==0 = Pretty.text "..."
| otherwise = f (go 0 ds) (PprUser q (PartWay (n-1)))
where
- go i [] = []
+ go _ [] = []
go i (d:ds) | i >= n = [text "...."]
| otherwise = d : go (i+1) ds
pprDeeperList f ds other_sty
= f ds other_sty
-pprSetDepth :: Int -> SDoc -> SDoc
-pprSetDepth n d (PprUser q _) = d (PprUser q (PartWay n))
-pprSetDepth n d other_sty = d other_sty
+pprSetDepth :: Depth -> SDoc -> SDoc
+pprSetDepth depth doc (PprUser q _) = doc (PprUser q depth)
+pprSetDepth _depth doc other_sty = doc other_sty
getPprStyle :: (PprStyle -> SDoc) -> SDoc
getPprStyle df sty = df sty sty
\end{code}
\begin{code}
-qualName :: PprStyle -> QualifyName
-qualName (PprUser (qual_name,_) _) m n = qual_name m n
-qualName other m n = Just (moduleName m)
+qualName :: PprStyle -> QueryQualifyName
+qualName (PprUser (qual_name,_) _) m n = qual_name m n
+qualName _other m _n = NameQual (moduleName m)
-qualModule :: PprStyle -> QualifyModule
-qualModule (PprUser (_,qual_mod) _) m = qual_mod m
-qualModule other m = Just (modulePackageId m)
+qualModule :: PprStyle -> QueryQualifyModule
+qualModule (PprUser (_,qual_mod) _) m = qual_mod m
+qualModule _other _m = True
codeStyle :: PprStyle -> Bool
codeStyle (PprCode _) = True
asmStyle :: PprStyle -> Bool
asmStyle (PprCode AsmStyle) = True
-asmStyle other = False
+asmStyle _other = False
dumpStyle :: PprStyle -> Bool
dumpStyle PprDump = True
-dumpStyle other = False
+dumpStyle _other = False
debugStyle :: PprStyle -> Bool
debugStyle PprDebug = True
-debugStyle other = False
+debugStyle _other = False
userStyle :: PprStyle -> Bool
userStyle (PprUser _ _) = True
-userStyle other = False
+userStyle _other = False
ifPprDebug :: SDoc -> SDoc -- Empty for non-debug style
ifPprDebug d sty@PprDebug = d sty
-ifPprDebug d sty = Pretty.empty
+ifPprDebug _ _ = Pretty.empty
\end{code}
\begin{code}
printErrs doc = do Pretty.printDoc PageMode stderr doc
hFlush stderr
+printOutput :: Doc -> IO ()
+printOutput doc = Pretty.printDoc PageMode stdout doc
+
printDump :: SDoc -> IO ()
-printDump doc = do
- Pretty.printDoc PageMode stdout (better_doc defaultDumpStyle)
- hFlush stdout
+printDump doc = hPrintDump stdout doc
+
+hPrintDump :: Handle -> SDoc -> IO ()
+hPrintDump h doc = do
+ Pretty.printDoc PageMode h (better_doc defaultDumpStyle)
+ hFlush h
where
- better_doc = doc $$ text ""
+ better_doc = doc $$ blankLine
printForUser :: Handle -> PrintUnqualified -> SDoc -> IO ()
printForUser handle unqual doc
= Pretty.printDoc PageMode handle (doc (mkUserStyle unqual AllTheWay))
+printForUserPartWay :: Handle -> Int -> PrintUnqualified -> SDoc -> IO ()
+printForUserPartWay handle d unqual doc
+ = Pretty.printDoc PageMode handle (doc (mkUserStyle unqual (PartWay d)))
+
-- printForC, printForAsm do what they sound like
printForC :: Handle -> SDoc -> IO ()
printForC handle doc = Pretty.printDoc LeftMode handle (doc (PprCode CStyle))
-- However, Doc *is* an instance of Show
-- showSDoc just blasts it out as a string
showSDoc :: SDoc -> String
-showSDoc d = show (d defaultUserStyle)
+showSDoc d = Pretty.showDocWith PageMode (d defaultUserStyle)
+
+-- 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 :: SDoc -> String
+showSDocOneLine d = Pretty.showDocWith PageMode (d defaultUserStyle)
showSDocForUser :: PrintUnqualified -> SDoc -> String
showSDocForUser unqual doc = show (doc (mkUserStyle unqual AllTheWay))
showSDocUnqual :: SDoc -> String
--- Only used in the gruesome HsExpr.isOperator
+-- Only used in the gruesome isOperator
showSDocUnqual d = show (d (mkUserStyle neverQualify AllTheWay))
showsPrecSDoc :: Int -> SDoc -> ShowS
showsPrecSDoc p d = showsPrec p (d defaultUserStyle)
showSDocDump :: SDoc -> String
-showSDocDump d = show (d PprDump)
+showSDocDump d = Pretty.showDocWith PageMode (d PprDump)
+
+showSDocDumpOneLine :: SDoc -> String
+showSDocDumpOneLine d = Pretty.showDocWith OneLineMode (d PprDump)
showSDocDebug :: SDoc -> String
showSDocDebug d = show (d PprDebug)
+
+showPpr :: Outputable a => a -> String
+showPpr = showSDoc . ppr
\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
+empty :: SDoc
+char :: Char -> SDoc
+text :: String -> SDoc
+ftext :: FastString -> SDoc
+ptext :: LitString -> SDoc
+int :: Int -> SDoc
+integer :: Integer -> SDoc
+float :: Float -> SDoc
+double :: Double -> SDoc
+rational :: Rational -> SDoc
+
+empty _sty = Pretty.empty
+char c _sty = Pretty.char c
+text s _sty = Pretty.text s
+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, braces, brackets, quotes, doubleQuotes, angleBrackets :: SDoc -> SDoc
parens d sty = Pretty.parens (d sty)
braces d sty = Pretty.braces (d sty)
doubleQuotes d sty = Pretty.doubleQuotes (d sty)
angleBrackets d = char '<' <> d <> char '>'
+cparen :: Bool -> SDoc -> SDoc
+
cparen b d sty = Pretty.cparen b (d sty)
-- quotes encloses something in single quotes...
-- 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
+ _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 '.'
+semi, comma, colon, equals, space, dcolon, arrow, underscore, dot :: SDoc
+darrow, lparen, rparen, lbrack, rbrack, lbrace, rbrace, blankLine :: SDoc
+
+blankLine _sty = Pretty.ptext (sLit "")
+dcolon _sty = Pretty.ptext (sLit "::")
+arrow _sty = Pretty.ptext (sLit "->")
+darrow _sty = Pretty.ptext (sLit "=>")
+semi _sty = Pretty.semi
+comma _sty = Pretty.comma
+colon _sty = Pretty.colon
+equals _sty = Pretty.equals
+space _sty = Pretty.space
+underscore = char '_'
+dot = char '.'
+lparen _sty = Pretty.lparen
+rparen _sty = Pretty.rparen
+lbrack _sty = Pretty.lbrack
+rbrack _sty = Pretty.rbrack
+lbrace _sty = Pretty.lbrace
+rbrace _sty = 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
+($$) :: SDoc -> SDoc -> SDoc
+-- ^ Join two 'SDoc' together vertically; if there is
+-- no vertical overlap it "dovetails" the two onto one line
+($+$) :: SDoc -> SDoc -> SDoc
+-- ^ Join two 'SDoc' together vertically
nest n d sty = Pretty.nest n (d sty)
(<>) d1 d2 sty = (Pretty.<>) (d1 sty) (d2 sty)
($$) d1 d2 sty = (Pretty.$$) (d1 sty) (d2 sty)
($+$) d1 d2 sty = (Pretty.$+$) (d1 sty) (d2 sty)
+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 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]
fsep ds sty = Pretty.fsep [d sty | d <- ds]
fcat ds sty = Pretty.fcat [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 sty = Pretty.hang (d1 sty) n (d2 sty)
-punctuate :: SDoc -> [SDoc] -> [SDoc]
-punctuate p [] = []
+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
\end{code}
%************************************************************************
\begin{code}
+-- | Class designating that some type has an 'SDoc' representation
class Outputable a where
ppr :: a -> SDoc
\end{code}
\begin{code}
instance Outputable Bool where
- ppr True = ptext SLIT("True")
- ppr False = ptext SLIT("False")
+ ppr True = ptext (sLit "True")
+ ppr False = ptext (sLit "False")
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 "()"
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
+ 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
+ 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
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])
+ 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 FastString where
ppr fs = ftext fs -- Prints an unadorned string,
-- no double quotes or anything
-
-instance Outputable PackageId where
- ppr pid = text (packageIdString pid)
\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}
+-- | '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
+ 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.
+-- 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 = text (show (unpackFS fs))
-\end{code}
+---------------------
+-- 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 '`'
+
+---------------------
+-- pprHsVar and pprHsInfix use the gruesome isOperator, which
+-- in turn uses (showSDoc (ppr v)), rather than isSymOcc (getOccName v).
+-- Reason: it means that pprHsVar doesn't need a NamedThing context,
+-- which none of the HsSyn printing functions do
+pprHsVar, pprHsInfix :: Outputable name => name -> SDoc
+pprHsVar v = pprPrefixVar (isOperator pp_v) pp_v
+ where pp_v = ppr v
+pprHsInfix v = pprInfixVar (isOperator pp_v) pp_v
+ where pp_v = ppr v
+
+isOperator :: SDoc -> Bool
+isOperator ppr_v
+ = case showSDocUnqual ppr_v of
+ ('(':_) -> False -- (), (,) etc
+ ('[':_) -> False -- []
+ ('$':c:_) -> not (isAlpha c) -- Don't treat $d as an operator
+ (':':c:_) -> not (isAlpha c) -- Don't treat :T as an operator
+ ('_':_) -> False -- Not an operator
+ (c:_) -> not (isAlpha c) -- Starts with non-alpha
+ _ -> False
+
+pprFastFilePath :: FastString -> SDoc
+pprFastFilePath path = text $ normalise $ unpackFS path
+\end{code}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-pprWithCommas :: (a -> SDoc) -> [a] -> SDoc
+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 seperated concatenation of the pretty printed things.
interppSP :: Outputable a => [a] -> SDoc
interppSP xs = sep (map ppr xs)
+-- | Returns the comma-seperated concatenation of the pretty printed things.
interpp'SP :: Outputable a => [a] -> SDoc
interpp'SP xs = sep (punctuate comma (map ppr xs))
+-- | Returns the comma-seperated concatenation of the quoted pretty printed things.
+--
+-- > [x,y,z] ==> `x', `y', `z'
pprQuotedList :: Outputable a => [a] -> SDoc
--- [x,y,z] ==> `x', `y', `z'
-pprQuotedList xs = hsep (punctuate comma (map (quotes . ppr) xs))
+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}
%* *
%************************************************************************
-@speakNth@ converts an integer to a verbal index; eg 1 maps to
-``first'' etc.
-
\begin{code}
+-- | 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 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 = 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 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' -- E.g. "no arguments"
-speakNOf 1 d = ptext SLIT("one") <+> d -- E.g. "one argument"
+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")
-
-plural [x] = empty
-plural xs = char 's'
+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'
\end{code}
%************************************************************************
\begin{code}
-pprPanic, pprPgmError :: String -> SDoc -> a
+pprPanic :: String -> SDoc -> a
+-- ^ Throw an exception saying "bug in GHC"
+pprPgmError :: String -> SDoc -> a
+-- ^ Throw an exception saying "bug in pgm being compiled" (used for unusual program errors)
pprTrace :: String -> SDoc -> a -> a
-pprPanic = pprAndThen panic -- Throw an exn saying "bug in GHC"
+-- ^ If debug output is on, show some 'SDoc' on the screen
+
+pprPanic = pprAndThen panic
+
+pprPgmError = pprAndThen pgmError
-pprPgmError = pprAndThen pgmError -- Throw an exn saying "bug in pgm being compiled"
- -- (used for unusual pgm errors)
-pprTrace = pprAndThen trace
+pprTrace str doc x
+ | opt_NoDebugOutput = x
+ | otherwise = pprAndThen trace str doc x
-pprPanic# heading pretty_msg = panic# (show (doc PprDebug))
+pprPanicFastInt :: String -> SDoc -> FastInt
+-- ^ Specialization of pprPanic that can be safely used with 'FastInt'
+pprPanicFastInt heading pretty_msg = panicFastInt (show (doc PprDebug))
where
doc = text heading <+> pretty_msg
doc = sep [text heading, nest 4 pretty_msg]
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
= panic (show (doc PprDebug))
where
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
+-- ^ Just warn about an assertion failure, recording the given file and line number.
+-- Should typically be accessed with the WARN macros
+warnPprTrace _ _file _line _msg x | opt_NoDebugOutput = x
+warnPprTrace False _file _line _msg x = x
+warnPprTrace True file line msg x
+ = trace (show (doc defaultDumpStyle)) x
where
doc = sep [hsep [text "WARNING: file", text file, text "line", int line],
msg]
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