memory-0.18.0: memory and related abstraction stuff

License | BSD-style
Maintainer | Vincent Hanquez <vincent@snarc.org>
Stability | experimental
Portability | unknown
Safe Haskell | None
Language | Haskell2010

Data.ByteArray.Encoding

Description

Base conversions for `ByteArray`.

Synopsis

- convertToBase :: (ByteArrayAccess bin, ByteArray bout) => Base -> bin -> bout
- convertFromBase :: (ByteArrayAccess bin, ByteArray bout) => Base -> bin -> Either String bout
- data Base
  - = Base16
  - | Base32
  - | Base64
  - | Base64URLUnpadded
  - | Base64OpenBSD

# Documentation

convertToBase :: (ByteArrayAccess bin, ByteArray bout) => Base -> bin -> bout #

Encode some bytes to the equivalent representation in a specific `Base`.

#### Examples

Convert a `ByteString` to base-64:

    >>> convertToBase Base64 ("foobar" :: ByteString) :: ByteString
    "Zm9vYmFy"

convertFromBase :: (ByteArrayAccess bin, ByteArray bout) => Base -> bin -> Either String bout #

Try to decode some bytes from the equivalent representation in a specific `Base`.

#### Examples

Successfully convert from base-64 to a `ByteString`:

    >>> convertFromBase Base64 ("Zm9vYmFy" :: ByteString) :: Either String ByteString
    Right "foobar"

Trying to decode invalid data will return an error string:

    >>> convertFromBase Base64 ("!!!" :: ByteString) :: Either String ByteString
    Left "base64: input: invalid length"

data Base #

The different bases that can be used.

See RFC4648 for details. In particular, Base64 can be standard or URL-safe. URL-safe encoding is often used in other specifications without padding characters.

RFC 2045 defines a separate Base64 encoding, which is not supported. This format requires a newline at least every 76 encoded characters, which works around limitations of older email programs that could not handle long lines. Be aware that other languages, such as Ruby, encode the RFC 2045 version by default. To decode their output, remove all newlines before decoding.

#### Examples

A quick example to show the differences:

    >>> let input = "Is 3 > 2?" :: ByteString
    >>> let convertedTo base = convertToBase base input :: ByteString
    >>> convertedTo Base16
    "49732033203e20323f"
    >>> convertedTo Base32
    "JFZSAMZAHYQDEPY="
    >>> convertedTo Base64
    "SXMgMyA+IDI/"
    >>> convertedTo Base64URLUnpadded
    "SXMgMyA-IDI_"
    >>> convertedTo Base64OpenBSD
    "QVKeKw.8GBG9"

Constructors

Base16 | similar to hexadecimal
Base32 |
Base64 | standard Base64
Base64URLUnpadded | unpadded URL-safe Base64
Base64OpenBSD | Base64 as used in OpenBSD password encoding (such as bcrypt)

#### Instances

Instances details

Show Base # |
Instance details Defined in Data.ByteArray.Encoding Methods showsPrec :: Int -> Base -> ShowS # show :: Base -> String # showList :: [Base] -> ShowS #
Eq Base # |
Instance details Defined in Data.ByteArray.Encoding Methods (==) :: Base -> Base -> Bool # (/=) :: Base -> Base -> Bool #