utf8-string-0.3.8: Support for reading and writing UTF8 Strings

Portability | portable This module provides fast, validated encoding and decoding functions between 'ByteString's and 'String's. It does not exactly match the output of the Codec.Binary.UTF8.String output for invalid encodings as the number of replacement characters is sometimes longer.
Stability | experimental
Maintainer | emertens@galois.com
Safe Haskell | Trustworthy

Data.ByteString.UTF8

Description

Synopsis

- data ByteString
- decode :: ByteString -> Maybe (Char, Int)
- replacement_char :: Char
- uncons :: ByteString -> Maybe (Char, ByteString)
- splitAt :: Int -> ByteString -> (ByteString, ByteString)
- take :: Int -> ByteString -> ByteString
- drop :: Int -> ByteString -> ByteString
- span :: (Char -> Bool) -> ByteString -> (ByteString, ByteString)
- break :: (Char -> Bool) -> ByteString -> (ByteString, ByteString)
- fromString :: String -> ByteString
- toString :: ByteString -> String
- foldl :: (a -> Char -> a) -> a -> ByteString -> a
- foldr :: (Char -> a -> a) -> a -> ByteString -> a
- length :: ByteString -> Int
- lines :: ByteString -> [ByteString]
- lines' :: ByteString -> [ByteString]

# Documentation

data ByteString Source

A space-efficient representation of a Word8 vector, supporting many efficient operations. A `ByteString` contains 8-bit characters only.

Instances of Eq, Ord, Read, Show, Data, Typeable

Instances

Eq ByteString |
Data ByteString |
Ord ByteString |
Read ByteString |
Show ByteString |
Typeable ByteString |
IsString ByteString |
Monoid ByteString |
NFData ByteString |
UTF8Bytes ByteString Int |

decode :: ByteString -> Maybe (Char, Int)

Try to extract a character from a byte string. Returns `Nothing` if there are no more bytes in the byte string. Otherwise, it returns a decoded character and the number of bytes used in its representation. Errors are replaced by character '\0xFFFD'.

replacement_char :: Char

This character is used to mark errors in a UTF8 encoded string.

uncons :: ByteString -> Maybe (Char, ByteString)

Get the first character of a byte string, if any. Malformed characters are replaced by '\0xFFFD'.

splitAt :: Int -> ByteString -> (ByteString, ByteString)

Split after a given number of characters. Negative values are treated as if they are 0.

take :: Int -> ByteString -> ByteString

`take n s` returns the first `n` characters of `s`. If `s` has less than `n` characters, then we return the whole of `s`.

drop :: Int -> ByteString -> ByteString

`drop n s` returns the `s` without its first `n` characters. If `s` has less than `n` characters, then we return an empty string.

span :: (Char -> Bool) -> ByteString -> (ByteString, ByteString)

Split a string into two parts: the first is the longest prefix that contains only characters that satisfy the predicate; the second part is the rest of the string. Invalid characters are passed as '\0xFFFD' to the predicate.

break :: (Char -> Bool) -> ByteString -> (ByteString, ByteString)

Split a string into two parts: the first is the longest prefix that contains only characters that do not satisfy the predicate; the second part is the rest of the string. Invalid characters are passed as '\0xFFFD' to the predicate.

fromString :: String -> ByteString

Converts a Haskell string into a UTF8 encoded bytestring.

toString :: ByteString -> String

Convert a UTF8 encoded bytestring into a Haskell string. Invalid characters are replaced with '\xFFFD'.

foldl :: (a -> Char -> a) -> a -> ByteString -> a

Traverse a bytestring (left biased). This function is strict in the accumulator.

foldr :: (Char -> a -> a) -> a -> ByteString -> a

Traverse a bytestring (right biased).

length :: ByteString -> Int

Counts the number of characters encoded in the bytestring. Note that this includes replacement characters.

lines :: ByteString -> [ByteString]

Split a string into a list of lines. Lines are terminated by '\n' or the end of the string. Empty lines may not be terminated by the end of the string. See also 'lines\''.

lines' :: ByteString -> [ByteString]

Split a string into a list of lines. Lines are terminated by '\n' or the end of the string. Empty lines may not be terminated by the end of the string. This function preserves the terminators. See also `lines`.