Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Data.FastString

Contents

ByteString
ShortByteString
FastZString
FastStrings
PtrStrings

Description

There are two principal string types used internally by GHC:

FastString

A compact, hash-consed, representation of character strings.
Generated by fsLit.
You can get a Unique from them.
Equality test is O(1) (it uses the Unique).
Comparison is O(1) or O(n):
O(n) but deterministic with lexical comparison (lexicalCompareFS)
O(1) but non-deterministic with Unique comparison (uniqCompareFS)
Turn into SDoc with ftext.

PtrString

Pointer and size of a Latin-1 encoded string.
Practically no operations.
Outputting them is fast.
Generated by mkPtrString#.
Length of string literals (mkPtrString# "abc"#) is computed statically
Turn into SDoc with ptext
Requires manual memory management. Improper use may lead to memory leaks or dangling pointers.
It assumes Latin-1 as the encoding, therefore it cannot represent arbitrary Unicode strings.

Use PtrString unless you want the facilities of FastString.

Synopsis

bytesFS :: FastString -> ByteString
fastStringToByteString :: FastString -> ByteString
mkFastStringByteString :: ByteString -> FastString
fastZStringToByteString :: FastZString -> ByteString
unsafeMkByteString :: String -> ByteString
fastStringToShortByteString :: FastString -> ShortByteString
mkFastStringShortByteString :: ShortByteString -> FastString
data FastZString
hPutFZS :: Handle -> FastZString -> IO ()
zString :: FastZString -> String
zStringTakeN :: Int -> FastZString -> String
lengthFZS :: FastZString -> Int
data FastString = FastString {
- uniq :: !Int
- n_chars :: !Int
- fs_sbs :: !ShortByteString
- fs_zenc :: FastZString
}
newtype NonDetFastString = NonDetFastString FastString
newtype LexicalFastString = LexicalFastString FastString
fsLit :: String -> FastString
mkFastString :: String -> FastString
mkFastStringBytes :: Ptr Word8 -> Int -> FastString
mkFastStringByteList :: [Word8] -> FastString
mkFastString# :: Addr# -> FastString
unpackFS :: FastString -> String
unconsFS :: FastString -> Maybe (Char, FastString)
zEncodeFS :: FastString -> FastZString
uniqueOfFS :: FastString -> Int
lengthFS :: FastString -> Int
nullFS :: FastString -> Bool
appendFS :: FastString -> FastString -> FastString
concatFS :: [FastString] -> FastString
consFS :: Char -> FastString -> FastString
nilFS :: FastString
lexicalCompareFS :: FastString -> FastString -> Ordering
uniqCompareFS :: FastString -> FastString -> Ordering
hPutFS :: Handle -> FastString -> IO ()
getFastStringTable :: IO [[[FastString]]]
getFastStringZEncCounter :: IO Int
data PtrString = PtrString !(Ptr Word8) !Int
mkPtrString# :: Addr# -> PtrString
unpackPtrString :: PtrString -> String
unpackPtrStringTakeN :: Int -> PtrString -> String
lengthPS :: PtrString -> Int

ByteString

bytesFS :: FastString -> ByteString Source #

Gives the Modified UTF-8 encoded bytes corresponding to a FastString

fastStringToByteString :: FastString -> ByteString Source #

Deprecated: Use bytesFS instead

Gives the Modified UTF-8 encoded bytes corresponding to a FastString

mkFastStringByteString :: ByteString -> FastString Source #

Create a FastString by copying an existing ByteString

fastZStringToByteString :: FastZString -> ByteString Source #

unsafeMkByteString :: String -> ByteString Source #

ShortByteString

fastStringToShortByteString :: FastString -> ShortByteString Source #

mkFastStringShortByteString :: ShortByteString -> FastString Source #

Create a FastString from an existing ShortByteString without copying.

FastZString

data FastZString Source #

Instances

Instances details

NFData FastZString Source #
Instance details Defined in GHC.Data.FastString Methods rnf :: FastZString -> () #

hPutFZS :: Handle -> FastZString -> IO () Source #

zString :: FastZString -> String Source #

zStringTakeN :: Int -> FastZString -> String Source #

zStringTakeN n = take n . zString but is performed in \(O(\min(n,l))\) rather than \(O(l)\), where \(l\) is the length of the FastZString.

lengthFZS :: FastZString -> Int Source #

FastStrings

data FastString Source #

A FastString is a UTF-8 encoded string together with a unique ID. All FastStrings are stored in a global hashtable to support fast O(1) comparison.

It is also associated with a lazy reference to the Z-encoding of this string which is used by the compiler internally.

Constructors

FastString
Fields uniq :: !Int n_chars :: !Int fs_sbs :: !ShortByteString fs_zenc :: FastZString Lazily computed Z-encoding of this string. See Note [Z-Encoding] in GHC.Utils.Encoding. Since `FastString`s are globally memoized this is computed at most once for any given string.

Instances

Instances details

Data FastString Source #
Instance details Defined in GHC.Data.FastString Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> FastString -> c FastString # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c FastString # toConstr :: FastString -> Constr # dataTypeOf :: FastString -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c FastString) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c FastString) # gmapT :: (forall b. Data b => b -> b) -> FastString -> FastString # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> FastString -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> FastString -> r # gmapQ :: (forall d. Data d => d -> u) -> FastString -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> FastString -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> FastString -> m FastString # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> FastString -> m FastString # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> FastString -> m FastString #
IsString FastString Source #
Instance details Defined in GHC.Data.FastString Methods fromString :: String -> FastString #
Monoid FastString Source #
Instance details Defined in GHC.Data.FastString Methods mempty :: FastString # mappend :: FastString -> FastString -> FastString # mconcat :: [FastString] -> FastString #
Semigroup FastString Source #
Instance details Defined in GHC.Data.FastString Methods (<>) :: FastString -> FastString -> FastString # sconcat :: NonEmpty FastString -> FastString # stimes :: Integral b => b -> FastString -> FastString #
Show FastString Source #
Instance details Defined in GHC.Data.FastString Methods showsPrec :: Int -> FastString -> ShowS # show :: FastString -> String # showList :: [FastString] -> ShowS #
NFData FastString Source #
Instance details Defined in GHC.Data.FastString Methods rnf :: FastString -> () #
Uniquable FastString Source #
Instance details Defined in GHC.Types.Unique Methods getUnique :: FastString -> Unique Source #
Binary FastString Source #
Instance details Defined in GHC.Utils.Binary Methods put_ :: BinHandle -> FastString -> IO () Source # put :: BinHandle -> FastString -> IO (Bin FastString) Source # get :: BinHandle -> IO FastString Source #
Outputable FastString Source #
Instance details Defined in GHC.Utils.Outputable Methods ppr :: FastString -> SDoc Source #
Eq FastString Source #
Instance details Defined in GHC.Data.FastString Methods (==) :: FastString -> FastString -> Bool # (/=) :: FastString -> FastString -> Bool #
type Anno FastString Source #
Instance details Defined in GHC.Hs.Expr type Anno FastString = SrcAnn NoEpAnns
type Anno (SourceText, RuleName) Source #
Instance details Defined in GHC.Hs.Decls type Anno (SourceText, RuleName) = SrcAnn NoEpAnns

newtype NonDetFastString Source #

Non-deterministic FastString

This is a simple FastString wrapper with an Ord instance using uniqCompareFS (i.e. which compares FastStrings on their Uniques). Hence it is not deterministic from one run to the other.

Constructors

NonDetFastString FastString

Instances

Instances details

Data NonDetFastString Source #
Instance details Defined in GHC.Data.FastString Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> NonDetFastString -> c NonDetFastString # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c NonDetFastString # toConstr :: NonDetFastString -> Constr # dataTypeOf :: NonDetFastString -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c NonDetFastString) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c NonDetFastString) # gmapT :: (forall b. Data b => b -> b) -> NonDetFastString -> NonDetFastString # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> NonDetFastString -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> NonDetFastString -> r # gmapQ :: (forall d. Data d => d -> u) -> NonDetFastString -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> NonDetFastString -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> NonDetFastString -> m NonDetFastString # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> NonDetFastString -> m NonDetFastString # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> NonDetFastString -> m NonDetFastString #
Show NonDetFastString Source #
Instance details Defined in GHC.Data.FastString Methods showsPrec :: Int -> NonDetFastString -> ShowS # show :: NonDetFastString -> String # showList :: [NonDetFastString] -> ShowS #
Binary NonDetFastString Source #
Instance details Defined in GHC.Utils.Binary Methods put_ :: BinHandle -> NonDetFastString -> IO () Source # put :: BinHandle -> NonDetFastString -> IO (Bin NonDetFastString) Source # get :: BinHandle -> IO NonDetFastString Source #
Outputable NonDetFastString Source #
Instance details Defined in GHC.Utils.Outputable Methods ppr :: NonDetFastString -> SDoc Source #
Eq NonDetFastString Source #
Instance details Defined in GHC.Data.FastString Methods (==) :: NonDetFastString -> NonDetFastString -> Bool # (/=) :: NonDetFastString -> NonDetFastString -> Bool #
Ord NonDetFastString Source #
Instance details Defined in GHC.Data.FastString Methods compare :: NonDetFastString -> NonDetFastString -> Ordering # (<) :: NonDetFastString -> NonDetFastString -> Bool # (<=) :: NonDetFastString -> NonDetFastString -> Bool # (>) :: NonDetFastString -> NonDetFastString -> Bool # (>=) :: NonDetFastString -> NonDetFastString -> Bool # max :: NonDetFastString -> NonDetFastString -> NonDetFastString # min :: NonDetFastString -> NonDetFastString -> NonDetFastString #

newtype LexicalFastString Source #

Lexical FastString

This is a simple FastString wrapper with an Ord instance using lexicalCompareFS (i.e. which compares FastStrings on their String representation). Hence it is deterministic from one run to the other.

Constructors

LexicalFastString FastString

Instances

Instances details

Data LexicalFastString Source #
Instance details Defined in GHC.Data.FastString Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> LexicalFastString -> c LexicalFastString # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c LexicalFastString # toConstr :: LexicalFastString -> Constr # dataTypeOf :: LexicalFastString -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c LexicalFastString) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c LexicalFastString) # gmapT :: (forall b. Data b => b -> b) -> LexicalFastString -> LexicalFastString # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> LexicalFastString -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> LexicalFastString -> r # gmapQ :: (forall d. Data d => d -> u) -> LexicalFastString -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> LexicalFastString -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> LexicalFastString -> m LexicalFastString # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> LexicalFastString -> m LexicalFastString # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> LexicalFastString -> m LexicalFastString #
Show LexicalFastString Source #
Instance details Defined in GHC.Data.FastString Methods showsPrec :: Int -> LexicalFastString -> ShowS # show :: LexicalFastString -> String # showList :: [LexicalFastString] -> ShowS #
Binary LexicalFastString Source #
Instance details Defined in GHC.Utils.Binary Methods put_ :: BinHandle -> LexicalFastString -> IO () Source # put :: BinHandle -> LexicalFastString -> IO (Bin LexicalFastString) Source # get :: BinHandle -> IO LexicalFastString Source #
Outputable LexicalFastString Source #
Instance details Defined in GHC.Utils.Outputable Methods ppr :: LexicalFastString -> SDoc Source #
Eq LexicalFastString Source #
Instance details Defined in GHC.Data.FastString Methods (==) :: LexicalFastString -> LexicalFastString -> Bool # (/=) :: LexicalFastString -> LexicalFastString -> Bool #
Ord LexicalFastString Source #
Instance details Defined in GHC.Data.FastString Methods compare :: LexicalFastString -> LexicalFastString -> Ordering # (<) :: LexicalFastString -> LexicalFastString -> Bool # (<=) :: LexicalFastString -> LexicalFastString -> Bool # (>) :: LexicalFastString -> LexicalFastString -> Bool # (>=) :: LexicalFastString -> LexicalFastString -> Bool # max :: LexicalFastString -> LexicalFastString -> LexicalFastString # min :: LexicalFastString -> LexicalFastString -> LexicalFastString #

Construction

fsLit :: String -> FastString Source #

mkFastString :: String -> FastString Source #

Creates a UTF-8 encoded FastString from a String

mkFastStringBytes :: Ptr Word8 -> Int -> FastString Source #

mkFastStringByteList :: [Word8] -> FastString Source #

Creates a FastString from a UTF-8 encoded [Word8]

mkFastString# :: Addr# -> FastString Source #

Deconstruction

unpackFS :: FastString -> String Source #

Lazily unpacks and decodes the FastString

unconsFS :: FastString -> Maybe (Char, FastString) Source #

Encoding

zEncodeFS :: FastString -> FastZString Source #

Returns a Z-encoded version of a FastString. This might be the original, if it was already Z-encoded. The first time this function is applied to a particular FastString, the results are memoized.

Operations

uniqueOfFS :: FastString -> Int Source #

lengthFS :: FastString -> Int Source #

Returns the length of the FastString in characters

nullFS :: FastString -> Bool Source #

Returns True if the FastString is empty

appendFS :: FastString -> FastString -> FastString Source #

concatFS :: [FastString] -> FastString Source #

consFS :: Char -> FastString -> FastString Source #

nilFS :: FastString Source #

lexicalCompareFS :: FastString -> FastString -> Ordering Source #

Compare FastString lexically

If you don't care about the lexical ordering, use uniqCompareFS instead.

uniqCompareFS :: FastString -> FastString -> Ordering Source #

Compare FastString by their Unique (not lexically).

Much cheaper than lexicalCompareFS but non-deterministic!

Outputting

hPutFS :: Handle -> FastString -> IO () Source #

Outputs a FastString with no decoding at all, that is, you get the actual bytes in the FastString written to the Handle.

Internal

getFastStringTable :: IO [[[FastString]]] Source #

getFastStringZEncCounter :: IO Int Source #

PtrStrings

data PtrString Source #

A PtrString is a pointer to some array of Latin-1 encoded chars.

Constructors

PtrString !(Ptr Word8) !Int

Construction

mkPtrString# :: Addr# -> PtrString Source #

Wrap an unboxed address into a PtrString.

Deconstruction

unpackPtrString :: PtrString -> String Source #

Decode a PtrString back into a String using Latin-1 encoding. This does not free the memory associated with PtrString.

unpackPtrStringTakeN :: Int -> PtrString -> String Source #

unpackPtrStringTakeN n = take n . unpackPtrString but is performed in \(O(\min(n,l))\) rather than \(O(l)\), where \(l\) is the length of the PtrString.

Operations

lengthPS :: PtrString -> Int Source #

Return the length of a PtrString