base16
Copyright(c) 2020-2026 Emily Pillmore
LicenseBSD-style
MaintainerEmily Pillmore <emilypi@cohomolo.gy>
Stabilitystable
Portabilitynon-portable
Safe HaskellNone
LanguageHaskell2010

Data.Text.Lazy.Encoding.Base16

Description

This module contains Text-valued combinators for implementing the RFC 4648 specification of the Base16 encoding format. This includes lenient decoding variants, as well as internal and external validation for canonicity.

Synopsis

Documentation

encodeBase16 :: Text -> Base16 Text Source #

Encode a lazy Text value in Base16.

See: RFC-4648 section 8

Examples:

>>> encodeBase16 "Sun"
"53756e"

decodeBase16 :: Base16 Text -> Text Source #

Decode a Base16-encoded lazy Text value.

See: RFC-4648 section 8

Examples:

>>> decodeBase16 $ assertBase16 "53756e"
"Sun"

decodeBase16Untyped :: Text -> Either Text Text Source #

Decode an untyped Base16-encoded lazy Text value.

See: RFC-4648 section 8

Examples:

>>> decodeBase16Untyped "53756e"
Right "Sun"
>>> decodeBase16Untyped "6x"
Left "invalid character at offset: 1"

decodeBase16With Source #

Arguments

:: (ByteString -> Either err Text)

convert a bytestring to text (e.g. decodeUtf8')

-> ByteString

Input to decode

-> Either (Base16Error err) Text 

Attempt to decode an untyped lazy Text value as Base16, converting from ByteString to Text according to some encoding function. In practice, This is something like decodeUtf8', which may produce an error.

See: RFC-4648 section 8

decodeBase16With decodeUtf8'
  :: ByteString -> Either (Base16Error UnicodeException) Text

Since: 0.3.0.0

decodeBase16Lenient :: Text -> Text Source #

Decode a Base16-encoded lazy Text value leniently.

Non-hexadecimal characters and a final unpaired hex digit are ignored. Valid UTF-8 sequences are preserved, including across chunk boundaries. Each invalid UTF-8 byte is interpreted as its Latin-1 character (U+0000 through U+00FF), so malformed input does not raise Unicode exceptions. Decoding remains lazy in the input chunks.

N.B.: this is not RFC 4648-compliant.

Examples:

>>> decodeBase16Lenient "53756e"
"Sun"
>>> decodeBase16Lenient "6x6x"
"f"

parseBase16 :: Text -> Either Text (Base16 Text) Source #

Validate an untyped Base16 value and retain its encoded representation.

Accepts even-length ASCII hexadecimal input, including upper-case and mixed-case digits. Empty input is valid. The original input is preserved, and errors match decodeBase16Untyped.

The whole input is validated before returning Right, regardless of chunk boundaries. The returned wrapper preserves those boundaries.

This validates the Base16 encoding, not the UTF-8 validity of its decoded payload. Use decodeBase16With with a checked conversion for text decoding.

Examples:

>>> parseBase16 "666f6"
Left "invalid bytestring size"
>>> parseBase16 "666F"
Right "666F"
>>> fmap decodeBase16 (parseBase16 "666F")
Right "fo"
>>> parseBase16 "6x"
Left "invalid character at offset: 1"

Since: 2.0