Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell2010 |
Synopsis
- data StringBuffer = StringBuffer {}
- hGetStringBuffer :: FilePath -> IO StringBuffer
- hGetStringBufferBlock :: Handle -> Int -> IO StringBuffer
- hPutStringBuffer :: Handle -> StringBuffer -> IO ()
- appendStringBuffers :: StringBuffer -> StringBuffer -> IO StringBuffer
- stringToStringBuffer :: String -> StringBuffer
- stringBufferFromByteString :: ByteString -> StringBuffer
- nextChar :: StringBuffer -> (Char, StringBuffer)
- currentChar :: StringBuffer -> Char
- prevChar :: StringBuffer -> Char -> Char
- atEnd :: StringBuffer -> Bool
- fingerprintStringBuffer :: StringBuffer -> Fingerprint
- stepOn :: StringBuffer -> StringBuffer
- offsetBytes :: Int -> StringBuffer -> StringBuffer
- byteDiff :: StringBuffer -> StringBuffer -> Int
- atLine :: Int -> StringBuffer -> Maybe StringBuffer
- lexemeToString :: StringBuffer -> Int -> String
- lexemeToFastString :: StringBuffer -> Int -> FastString
- decodePrevNChars :: Int -> StringBuffer -> String
- parseUnsignedInteger :: StringBuffer -> Int -> Integer -> (Char -> Int) -> Integer
- containsBidirectionalFormatChar :: StringBuffer -> Bool
- bidirectionalFormatChars :: [(Char, String)]
Documentation
data StringBuffer Source #
A StringBuffer is an internal pointer to a sized chunk of bytes. The bytes are intended to be *immutable*. There are pure operations to read the contents of a StringBuffer.
A StringBuffer may have a finalizer, depending on how it was obtained.
Instances
Show StringBuffer Source # | |
Defined in GHC.Data.StringBuffer |
Creation/destruction
hGetStringBuffer :: FilePath -> IO StringBuffer Source #
Read a file into a StringBuffer
. The resulting buffer is automatically
managed by the garbage collector.
hGetStringBufferBlock :: Handle -> Int -> IO StringBuffer Source #
hPutStringBuffer :: Handle -> StringBuffer -> IO () Source #
stringToStringBuffer :: String -> StringBuffer Source #
Encode a String
into a StringBuffer
as UTF-8. The resulting buffer
is automatically managed by the garbage collector.
stringBufferFromByteString :: ByteString -> StringBuffer Source #
Convert a UTF-8 encoded ByteString
into a 'StringBuffer. This really
relies on the internals of both ByteString
and StringBuffer
.
O(n) (but optimized into a memcpy
by bytestring
under the hood)
Inspection
nextChar :: StringBuffer -> (Char, StringBuffer) Source #
Return the first UTF-8 character of a nonempty StringBuffer
and as well
the remaining portion (analogous to uncons
). Warning: The
behavior is undefined if the StringBuffer
is empty. The result shares
the same buffer as the original. Similar to utf8DecodeChar
, if the
character cannot be decoded as UTF-8, '\0'
is returned.
currentChar :: StringBuffer -> Char Source #
Return the first UTF-8 character of a nonempty StringBuffer
(analogous
to head
). Warning: The behavior is undefined if the
StringBuffer
is empty. Similar to utf8DecodeChar
, if the character
cannot be decoded as UTF-8, '\0'
is returned.
atEnd :: StringBuffer -> Bool Source #
Check whether a StringBuffer
is empty (analogous to null
).
fingerprintStringBuffer :: StringBuffer -> Fingerprint Source #
Computes a hash of the contents of a StringBuffer
.
Moving and comparison
stepOn :: StringBuffer -> StringBuffer Source #
Return a StringBuffer
with the first UTF-8 character removed (analogous
to tail
). Warning: The behavior is undefined if the
StringBuffer
is empty. The result shares the same buffer as the
original.
:: Int |
|
-> StringBuffer | |
-> StringBuffer |
Return a StringBuffer
with the first n
bytes removed. Warning:
If there aren't enough characters, the returned StringBuffer
will be
invalid and any use of it may lead to undefined behavior. The result
shares the same buffer as the original.
byteDiff :: StringBuffer -> StringBuffer -> Int Source #
Compute the difference in offset between two StringBuffer
s that share
the same buffer. Warning: The behavior is undefined if the
StringBuffer
s use separate buffers.
atLine :: Int -> StringBuffer -> Maybe StringBuffer Source #
Computes a StringBuffer
which points to the first character of the
wanted line. Lines begin at 1.
Conversion
:: StringBuffer | |
-> Int |
|
-> String |
Decode the first n
bytes of a StringBuffer
as UTF-8 into a String
.
Similar to utf8DecodeChar
, if the character cannot be decoded as UTF-8,
they will be replaced with '\0'
.
:: StringBuffer | |
-> Int |
|
-> FastString |
decodePrevNChars :: Int -> StringBuffer -> String Source #
Return the previous n
characters (or fewer if we are less than n
characters into the buffer.
Parsing integers
parseUnsignedInteger :: StringBuffer -> Int -> Integer -> (Char -> Int) -> Integer Source #
Checking for bi-directional format characters
containsBidirectionalFormatChar :: StringBuffer -> Bool Source #
Returns true if the buffer contains Unicode bi-directional formatting characters.
https://www.unicode.org/reports/tr9/#Bidirectional_Character_Types
Bidirectional format characters are one of 'x202a' : "U+202A LEFT-TO-RIGHT EMBEDDING (LRE)" 'x202b' : "U+202B RIGHT-TO-LEFT EMBEDDING (RLE)" 'x202c' : "U+202C POP DIRECTIONAL FORMATTING (PDF)" 'x202d' : "U+202D LEFT-TO-RIGHT OVERRIDE (LRO)" 'x202e' : "U+202E RIGHT-TO-LEFT OVERRIDE (RLO)" 'x2066' : "U+2066 LEFT-TO-RIGHT ISOLATE (LRI)" 'x2067' : "U+2067 RIGHT-TO-LEFT ISOLATE (RLI)" 'x2068' : "U+2068 FIRST STRONG ISOLATE (FSI)" 'x2069' : "U+2069 POP DIRECTIONAL ISOLATE (PDI)"
This list is encoded in bidirectionalFormatChars
bidirectionalFormatChars :: [(Char, String)] Source #