| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
GHC.Data.StringBuffer
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.
Constructors
| StringBuffer | |
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.
Arguments
| :: 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 StringBuffers that share
the same buffer. Warning: The behavior is undefined if the
StringBuffers 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
Arguments
| :: 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'.
Arguments
| :: 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 #