Safe Haskell | None |
---|---|
Language | Haskell2010 |
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.
- class Outputable a where
- class Outputable a => OutputableBndr a where
- data SDoc
- runSDoc :: SDoc -> SDocContext -> Doc
- initSDocContext :: DynFlags -> PprStyle -> SDocContext
- docToSDoc :: Doc -> SDoc
- sdocWithPprDebug :: (Bool -> SDoc) -> SDoc
- interppSP :: Outputable a => [a] -> SDoc
- interpp'SP :: Outputable a => [a] -> SDoc
- pprQuotedList :: Outputable a => [a] -> SDoc
- pprWithCommas :: (a -> SDoc) -> [a] -> SDoc
- quotedListWithOr :: [SDoc] -> SDoc
- quotedListWithNor :: [SDoc] -> SDoc
- pprWithBars :: (a -> SDoc) -> [a] -> SDoc
- empty :: SDoc
- isEmpty :: DynFlags -> SDoc -> Bool
- nest :: Int -> SDoc -> SDoc
- char :: Char -> SDoc
- text :: String -> SDoc
- ftext :: FastString -> SDoc
- ptext :: LitString -> SDoc
- ztext :: FastZString -> SDoc
- int :: Int -> SDoc
- intWithCommas :: Integral a => a -> SDoc
- integer :: Integer -> SDoc
- float :: Float -> SDoc
- double :: Double -> SDoc
- rational :: Rational -> SDoc
- doublePrec :: Int -> Double -> SDoc
- parens :: SDoc -> SDoc
- cparen :: Bool -> SDoc -> SDoc
- brackets :: SDoc -> SDoc
- braces :: SDoc -> SDoc
- quotes :: SDoc -> SDoc
- quote :: SDoc -> SDoc
- doubleQuotes :: SDoc -> SDoc
- angleBrackets :: SDoc -> SDoc
- paBrackets :: SDoc -> SDoc
- semi :: SDoc
- comma :: SDoc
- colon :: SDoc
- dcolon :: SDoc
- space :: SDoc
- equals :: SDoc
- dot :: SDoc
- vbar :: SDoc
- arrow :: SDoc
- larrow :: SDoc
- darrow :: SDoc
- arrowt :: SDoc
- larrowt :: SDoc
- arrowtt :: SDoc
- larrowtt :: SDoc
- lparen :: SDoc
- rparen :: SDoc
- lbrack :: SDoc
- rbrack :: SDoc
- lbrace :: SDoc
- rbrace :: SDoc
- underscore :: SDoc
- blankLine :: SDoc
- forAllLit :: SDoc
- kindStar :: SDoc
- bullet :: SDoc
- (<>) :: SDoc -> SDoc -> SDoc
- (<+>) :: SDoc -> SDoc -> SDoc
- hcat :: [SDoc] -> SDoc
- hsep :: [SDoc] -> SDoc
- ($$) :: SDoc -> SDoc -> SDoc
- ($+$) :: SDoc -> SDoc -> SDoc
- vcat :: [SDoc] -> SDoc
- sep :: [SDoc] -> SDoc
- cat :: [SDoc] -> SDoc
- fsep :: [SDoc] -> SDoc
- fcat :: [SDoc] -> SDoc
- hang :: SDoc -> Int -> SDoc -> SDoc
- hangNotEmpty :: SDoc -> Int -> SDoc -> SDoc
- punctuate :: SDoc -> [SDoc] -> [SDoc]
- ppWhen :: Bool -> SDoc -> SDoc
- ppUnless :: Bool -> SDoc -> SDoc
- speakNth :: Int -> SDoc
- speakN :: Int -> SDoc
- speakNOf :: Int -> SDoc -> SDoc
- plural :: [a] -> SDoc
- isOrAre :: [a] -> SDoc
- doOrDoes :: [a] -> SDoc
- unicodeSyntax :: SDoc -> SDoc -> SDoc
- coloured :: PprColour -> SDoc -> SDoc
- keyword :: SDoc -> SDoc
- printSDoc :: Mode -> DynFlags -> Handle -> PprStyle -> SDoc -> IO ()
- printSDocLn :: Mode -> DynFlags -> Handle -> PprStyle -> SDoc -> IO ()
- printForUser :: DynFlags -> Handle -> PrintUnqualified -> SDoc -> IO ()
- printForUserPartWay :: DynFlags -> Handle -> Int -> PrintUnqualified -> SDoc -> IO ()
- printForC :: DynFlags -> Handle -> SDoc -> IO ()
- bufLeftRenderSDoc :: DynFlags -> BufHandle -> PprStyle -> SDoc -> IO ()
- pprCode :: CodeStyle -> SDoc -> SDoc
- mkCodeStyle :: CodeStyle -> PprStyle
- showSDoc :: DynFlags -> SDoc -> String
- showSDocUnsafe :: SDoc -> String
- showSDocOneLine :: DynFlags -> SDoc -> String
- showSDocForUser :: DynFlags -> PrintUnqualified -> SDoc -> String
- showSDocDebug :: DynFlags -> SDoc -> String
- showSDocDump :: DynFlags -> SDoc -> String
- showSDocDumpOneLine :: DynFlags -> SDoc -> String
- showSDocUnqual :: DynFlags -> SDoc -> String
- showPpr :: Outputable a => DynFlags -> a -> String
- renderWithStyle :: DynFlags -> SDoc -> PprStyle -> String
- pprInfixVar :: Bool -> SDoc -> SDoc
- pprPrefixVar :: Bool -> SDoc -> SDoc
- pprHsChar :: Char -> SDoc
- pprHsString :: FastString -> SDoc
- pprHsBytes :: ByteString -> SDoc
- primFloatSuffix :: SDoc
- primCharSuffix :: SDoc
- primWordSuffix :: SDoc
- primDoubleSuffix :: SDoc
- primInt64Suffix :: SDoc
- primWord64Suffix :: SDoc
- primIntSuffix :: SDoc
- pprPrimChar :: Char -> SDoc
- pprPrimInt :: Integer -> SDoc
- pprPrimWord :: Integer -> SDoc
- pprPrimInt64 :: Integer -> SDoc
- pprPrimWord64 :: Integer -> SDoc
- pprFastFilePath :: FastString -> SDoc
- data BindingSite
- data PprStyle
- data CodeStyle
- data PrintUnqualified = QueryQualify {}
- type QueryQualifyName = Module -> OccName -> QualifyName
- type QueryQualifyModule = Module -> Bool
- type QueryQualifyPackage = UnitId -> Bool
- reallyAlwaysQualify :: PrintUnqualified
- reallyAlwaysQualifyNames :: QueryQualifyName
- alwaysQualify :: PrintUnqualified
- alwaysQualifyNames :: QueryQualifyName
- alwaysQualifyModules :: QueryQualifyModule
- neverQualify :: PrintUnqualified
- neverQualifyNames :: QueryQualifyName
- neverQualifyModules :: QueryQualifyModule
- alwaysQualifyPackages :: QueryQualifyPackage
- neverQualifyPackages :: QueryQualifyPackage
- data QualifyName
- queryQual :: PprStyle -> PrintUnqualified
- sdocWithDynFlags :: (DynFlags -> SDoc) -> SDoc
- sdocWithPlatform :: (Platform -> SDoc) -> SDoc
- getPprStyle :: (PprStyle -> SDoc) -> SDoc
- withPprStyle :: PprStyle -> SDoc -> SDoc
- withPprStyleDoc :: DynFlags -> PprStyle -> SDoc -> Doc
- setStyleColoured :: Bool -> PprStyle -> PprStyle
- pprDeeper :: SDoc -> SDoc
- pprDeeperList :: ([SDoc] -> SDoc) -> [SDoc] -> SDoc
- pprSetDepth :: Depth -> SDoc -> SDoc
- codeStyle :: PprStyle -> Bool
- userStyle :: PprStyle -> Bool
- debugStyle :: PprStyle -> Bool
- dumpStyle :: PprStyle -> Bool
- asmStyle :: PprStyle -> Bool
- ifPprDebug :: SDoc -> SDoc
- qualName :: PprStyle -> QueryQualifyName
- qualModule :: PprStyle -> QueryQualifyModule
- qualPackage :: PprStyle -> QueryQualifyPackage
- mkErrStyle :: DynFlags -> PrintUnqualified -> PprStyle
- defaultErrStyle :: DynFlags -> PprStyle
- defaultDumpStyle :: DynFlags -> PprStyle
- mkDumpStyle :: DynFlags -> PrintUnqualified -> PprStyle
- defaultUserStyle :: DynFlags -> PprStyle
- mkUserStyle :: DynFlags -> PrintUnqualified -> Depth -> PprStyle
- cmdlineParserStyle :: DynFlags -> PprStyle
- data Depth
- pprPanic :: HasCallStack => String -> SDoc -> a
- pprSorry :: String -> SDoc -> a
- assertPprPanic :: HasCallStack => String -> Int -> SDoc -> a
- pprPgmError :: String -> SDoc -> a
- pprTrace :: String -> SDoc -> a -> a
- pprTraceDebug :: String -> SDoc -> a -> a
- pprTraceIt :: Outputable a => String -> a -> a
- warnPprTrace :: Bool -> String -> Int -> SDoc -> a -> a
- pprSTrace :: HasCallStack => SDoc -> a -> a
- trace :: String -> a -> a
- pgmError :: String -> a
- panic :: String -> a
- sorry :: String -> a
- assertPanic :: String -> Int -> a
- pprDebugAndThen :: DynFlags -> (String -> a) -> SDoc -> SDoc -> a
- callStackDoc :: HasCallStack => SDoc
Type classes
class Outputable a where #
Class designating that some type has an SDoc
representation
class Outputable a => OutputableBndr a where #
When we print a binder, we often want to print its type too.
The OutputableBndr
class encapsulates this idea.
pprBndr :: BindingSite -> a -> SDoc #
pprPrefixOcc, pprInfixOcc :: a -> SDoc #
bndrIsJoin_maybe :: a -> Maybe Int #
Pretty printing combinators
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.
initSDocContext :: DynFlags -> PprStyle -> SDocContext #
sdocWithPprDebug :: (Bool -> SDoc) -> SDoc #
interppSP :: Outputable a => [a] -> SDoc #
Returns the separated concatenation of the pretty printed things.
interpp'SP :: Outputable a => [a] -> SDoc #
Returns the comma-separated concatenation of the pretty printed things.
pprQuotedList :: Outputable a => [a] -> SDoc #
Returns the comma-separated concatenation of the quoted pretty printed things.
[x,y,z] ==> `x', `y', `z'
quotedListWithOr :: [SDoc] -> SDoc #
quotedListWithNor :: [SDoc] -> SDoc #
ftext :: FastString -> SDoc #
ztext :: FastZString -> SDoc #
intWithCommas :: Integral a => a -> SDoc #
doublePrec :: Int -> Double -> SDoc #
doublePrec p n
shows a floating point number n
with p
digits of precision after the decimal point.
doubleQuotes :: SDoc -> SDoc #
angleBrackets :: SDoc -> SDoc #
paBrackets :: SDoc -> SDoc #
underscore :: SDoc #
($$) :: SDoc -> SDoc -> SDoc #
Join two SDoc
together vertically; if there is
no vertical overlap it "dovetails" the two onto one line
A paragraph-fill combinator. It's much like sep, only it keeps fitting things on one line until it can't fit any more.
hangNotEmpty :: SDoc -> Int -> SDoc -> SDoc #
This behaves like hang
, but does not indent the second document
when the header is empty.
Converts an integer to a verbal index:
speakNth 1 = text "first" speakNth 5 = text "fifth" speakNth 21 = text "21st"
Converts an integer to a verbal multiplicity:
speakN 0 = text "none" speakN 5 = text "five" speakN 10 = text "10"
speakNOf :: Int -> SDoc -> SDoc #
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"
Determines the pluralisation suffix appropriate for the length of a list:
plural [] = char 's' plural ["Hello"] = empty plural ["Hello", "World"] = 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"
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"
unicodeSyntax :: SDoc -> SDoc -> SDoc #
coloured :: PprColour -> SDoc -> SDoc #
Apply the given colour/style for the argument.
Only takes effect if colours are enabled.
Converting SDoc
into strings and outputing it
printSDocLn :: Mode -> DynFlags -> Handle -> PprStyle -> SDoc -> IO () #
Like printSDoc
but appends an extra newline.
printForUser :: DynFlags -> Handle -> PrintUnqualified -> SDoc -> IO () #
printForUserPartWay :: DynFlags -> Handle -> Int -> PrintUnqualified -> SDoc -> IO () #
printForC :: DynFlags -> Handle -> SDoc -> IO () #
Like printSDocLn
but specialized with LeftMode
and
. This is typically used to output C-- code.PprCode
CStyle
mkCodeStyle :: CodeStyle -> PprStyle #
showSDocUnsafe :: SDoc -> String #
showSDocOneLine :: DynFlags -> SDoc -> String #
showSDocForUser :: DynFlags -> PrintUnqualified -> SDoc -> String #
showSDocDebug :: DynFlags -> SDoc -> String #
showSDocDump :: DynFlags -> SDoc -> String #
showSDocDumpOneLine :: DynFlags -> SDoc -> String #
showSDocUnqual :: DynFlags -> SDoc -> String #
showPpr :: Outputable a => DynFlags -> a -> String #
pprInfixVar :: Bool -> SDoc -> SDoc #
pprPrefixVar :: Bool -> SDoc -> SDoc #
pprHsString :: FastString -> SDoc #
Special combinator for showing string literals.
pprHsBytes :: ByteString -> SDoc #
Special combinator for showing bytestring literals.
primFloatSuffix :: SDoc #
primCharSuffix :: SDoc #
primWordSuffix :: SDoc #
primInt64Suffix :: SDoc #
primIntSuffix :: SDoc #
pprPrimChar :: Char -> SDoc #
Special combinator for showing unboxed literals.
pprPrimInt :: Integer -> SDoc #
pprPrimWord :: Integer -> SDoc #
pprPrimInt64 :: Integer -> SDoc #
pprPrimWord64 :: Integer -> SDoc #
pprFastFilePath :: FastString -> SDoc #
Controlling the style in which output is printed
data BindingSite #
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
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) |
data PrintUnqualified #
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
.
type QueryQualifyName = Module -> OccName -> QualifyName #
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 function 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 QueryQualifyModule = Module -> Bool #
For a given module, we need to know whether to print it with a package name to disambiguate it.
type QueryQualifyPackage = UnitId -> Bool #
For a given package, we need to know whether to print it with the component id to disambiguate it.
alwaysQualifyNames :: QueryQualifyName #
NB: This won't ever show package IDs
data QualifyName #
queryQual :: PprStyle -> PrintUnqualified #
sdocWithDynFlags :: (DynFlags -> SDoc) -> SDoc #
sdocWithPlatform :: (Platform -> SDoc) -> SDoc #
getPprStyle :: (PprStyle -> SDoc) -> SDoc #
withPprStyle :: PprStyle -> SDoc -> SDoc #
withPprStyleDoc :: DynFlags -> PprStyle -> SDoc -> Doc #
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.
setStyleColoured :: Bool -> PprStyle -> PprStyle #
pprDeeperList :: ([SDoc] -> SDoc) -> [SDoc] -> SDoc #
Truncate a list that is longer than the current depth.
pprSetDepth :: Depth -> SDoc -> SDoc #
debugStyle :: PprStyle -> Bool #
ifPprDebug :: SDoc -> SDoc #
qualName :: PprStyle -> QueryQualifyName #
mkErrStyle :: DynFlags -> PrintUnqualified -> PprStyle #
Style for printing error messages
defaultErrStyle :: DynFlags -> PprStyle #
defaultDumpStyle :: DynFlags -> PprStyle #
mkDumpStyle :: DynFlags -> PrintUnqualified -> PprStyle #
defaultUserStyle :: DynFlags -> PprStyle #
mkUserStyle :: DynFlags -> PrintUnqualified -> Depth -> PprStyle #
cmdlineParserStyle :: DynFlags -> PprStyle #
Error handling and debugging utilities
pprPanic :: HasCallStack => String -> SDoc -> a #
Throw an exception saying "bug in GHC"
assertPprPanic :: HasCallStack => 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
pprPgmError :: String -> SDoc -> a #
Throw an exception saying "bug in pgm being compiled" (used for unusual program errors)
pprTraceDebug :: String -> SDoc -> a -> a #
pprTraceIt :: Outputable a => String -> a -> a #
pprTraceIt desc x
is equivalent to pprTrace desc (ppr x) x
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
pprSTrace :: HasCallStack => SDoc -> a -> a #
If debug output is on, show some SDoc
on the screen along
with a call stack when available.
trace :: String -> a -> a Source #
The trace
function outputs the trace message given as its first argument,
before returning the second argument as its result.
For example, this returns the value of f x
but first outputs the message.
trace ("calling f with x = " ++ show x) (f x)
The trace
function should only be used for debugging, or for monitoring
execution. The function is not referentially transparent: its type indicates
that it is a pure function but it has the side effect of outputting the
trace message.
assertPanic :: String -> Int -> a #
Throw an failed assertion exception for a given filename and line number.
callStackDoc :: HasCallStack => SDoc #