GHC.IO.Encoding.Failure

base-4.8.2.0: Basic libraries

Copyright | (c) The University of Glasgow, 2008-2011
License | see libraries/base/LICENSE
Maintainer | libraries@haskell.org
Stability | internal
Portability | non-portable
Safe Haskell | Trustworthy
Language | Haskell2010

GHC.IO.Encoding.Failure

Description

Types for specifying how text encoding/decoding fails

Synopsis

- data CodingFailureMode
  - = ErrorOnCodingFailure
  - | IgnoreCodingFailure
  - | TransliterateCodingFailure
  - | RoundtripFailure
- codingFailureModeSuffix :: CodingFailureMode -> String
- isSurrogate :: Char -> Bool
- recoverDecode :: CodingFailureMode -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)
- recoverEncode :: CodingFailureMode -> Buffer Char -> Buffer Word8 -> IO (Buffer Char, Buffer Word8)

# Documentation

data CodingFailureMode

The `CodingFailureMode` is used to construct `TextEncoding`s, and specifies how they handle illegal sequences.

Constructors

ErrorOnCodingFailure | Throw an error when an illegal sequence is encountered
IgnoreCodingFailure | Attempt to ignore and recover if an illegal sequence is encountered
TransliterateCodingFailure | Replace with the closest visual match upon an illegal sequence
RoundtripFailure | Use the private-use escape mechanism to attempt to allow illegal sequences to be roundtripped.

Instances

Show CodingFailureMode |

codingFailureModeSuffix :: CodingFailureMode -> String

isSurrogate :: Char -> Bool

Some characters are actually "surrogate" codepoints defined for use in UTF-16. We need to signal an invalid character if we detect them when encoding a sequence of `Char`s into `Word8`s because they won't give valid Unicode.

We may also need to signal an invalid character if we detect them when encoding a sequence of `Char`s into `Word8`s because the `RoundtripFailure` mode creates these to round-trip bytes through our internal UTF-16 encoding.

recoverDecode :: CodingFailureMode -> Buffer Word8 -> Buffer Char -> IO (Buffer Word8, Buffer Char)

recoverEncode :: CodingFailureMode -> Buffer Char -> Buffer Word8 -> IO (Buffer Char, Buffer Word8)