Safe Haskell | None |
---|---|
Language | Haskell2010 |
A library for efficiently building up a buffer of data. When given data known to be strict, use of BufferBuilder compiles directly into a series of efficient C function calls.
- data BufferBuilder a
- runBufferBuilder :: BufferBuilder () -> ByteString
- appendByte :: Word8 -> BufferBuilder ()
- appendChar8 :: Char -> BufferBuilder ()
- appendBS :: ByteString -> BufferBuilder ()
- appendLBS :: ByteString -> BufferBuilder ()
- appendLiteral :: Addr# -> BufferBuilder ()
- unsafeAppendLiteralN :: Int -> Addr# -> BufferBuilder ()
- appendByte7 :: Word8 -> BufferBuilder ()
- appendChar7 :: Char -> BufferBuilder ()
- appendBS7 :: ByteString -> BufferBuilder ()
- appendLiteral7 :: Addr# -> BufferBuilder ()
- unsafeAppendLiteralN7 :: Int -> Addr# -> BufferBuilder ()
- appendCharUtf8 :: Char -> BufferBuilder ()
- appendStringUtf8 :: String -> BufferBuilder ()
- appendDecimalSignedInt :: Int -> BufferBuilder ()
- appendDecimalDouble :: Double -> BufferBuilder ()
- appendEscapedJson :: ByteString -> BufferBuilder ()
- appendEscapedJsonLiteral :: Addr# -> BufferBuilder ()
- appendEscapedJsonText :: Text -> BufferBuilder ()
The BufferBuilder Monad
data BufferBuilder a Source #
BufferBuilder is the type of a monadic action that appends to an implicit,
growable buffer. Use runBufferBuilder
to extract the resulting
buffer as a ByteString
.
runBufferBuilder :: BufferBuilder () -> ByteString Source #
Run a sequence of BufferBuilder
actions and extract the resulting
buffer as a ByteString
.
Appending bytes and byte strings
appendByte :: Word8 -> BufferBuilder () Source #
Append a single byte to the output buffer. To append multiple bytes in sequence and
avoid redundant bounds checks, consider using appendBS
, appendLiteral
, or unsafeAppendLiteralN
.
appendChar8 :: Char -> BufferBuilder () Source #
Appends a character to the buffer, truncating it to the bottom 8 bits.
appendBS :: ByteString -> BufferBuilder () Source #
Appends a ByteString
to the buffer. When appending constant, hardcoded strings, to
avoid a CAF and the costs of its associated tag check and indirect jump, use
appendLiteral
or unsafeAppendLiteralN
instead.
appendLBS :: ByteString -> BufferBuilder () Source #
Appends a lazy ByteString
to the buffer. This function operates by traversing
the lazy ByteString
chunks, appending each in turn.
appendLiteral :: Addr# -> BufferBuilder () Source #
Appends a zero-terminated MagicHash string literal. Use this function instead of
appendBS
for string constants. For example:
appendLiteral "true"#
If the length of the string literal is known, calling
unsafeAppendLiteralN
is faster, as unsafeAppendLiteralN
avoids a strlen
operation which has nontrivial cost in some benchmarks.
unsafeAppendLiteralN :: Int -> Addr# -> BufferBuilder () Source #
Appends a MagicHash string literal with a known length. Use this when the string literal's length is known. For example:
unsafeAppendLiteralN 4 "true"#
Per byte, this is the fastest append function. It amounts to a C function call with two constant arguments. The C function checks to see if it needs to grow the buffer and then it simply calls memcpy.
WARNING: passing an incorrect length value is likely to cause an access violation or worse.
Appending bytes and byte strings, truncated to 7 bits
appendByte7 :: Word8 -> BufferBuilder () Source #
appendChar7 :: Char -> BufferBuilder () Source #
appendBS7 :: ByteString -> BufferBuilder () Source #
appendLiteral7 :: Addr# -> BufferBuilder () Source #
unsafeAppendLiteralN7 :: Int -> Addr# -> BufferBuilder () Source #
UTF-8 encoding
appendCharUtf8 :: Char -> BufferBuilder () Source #
Appends a UTF-8-encoded Char
to the buffer.
appendStringUtf8 :: String -> BufferBuilder () Source #
Appends a UTF-8-encoded String
to the buffer. The best way to improve performance here
is to use ByteString
or Text
instead of String
.
Printing numbers
appendDecimalSignedInt :: Int -> BufferBuilder () Source #
Appends a decimal integer, just like calling printf("%d", ...)
appendDecimalDouble :: Double -> BufferBuilder () Source #
Appends a decimal double, just like calling printf("%f", ...)
JSON escaping
appendEscapedJson :: ByteString -> BufferBuilder () Source #
appendEscapedJsonLiteral :: Addr# -> BufferBuilder () Source #
appendEscapedJsonText :: Text -> BufferBuilder () Source #