NAME¶
Unicode::UTF8 - Encoding and decoding of UTF-8 encoding form
SYNOPSIS¶
use Unicode::UTF8 qw[decode_utf8 encode_utf8];
use warnings FATAL => 'utf8'; # fatalize encoding glitches
$string = decode_utf8($octets);
$octets = encode_utf8($string);
DESCRIPTION¶
This module provides functions to encode and decode UTF-8 encoding form as
specified by Unicode and ISO/IEC 10646:2011.
FUNCTIONS¶
decode_utf8¶
$string = decode_utf8($octets);
$string = decode_utf8($octets, $fallback);
Returns an decoded representation of $octets in UTF-8 encoding as a character
string.
$fallback is an optional "CODE" reference which provides a
error-handling mechanism, allowing customization of error handling. The
default error-handling mechanism is to replace any ill-formed UTF-8 sequences
or encoded code points which can't be interchanged with REPLACEMENT CHARACTER
(U+FFFD).
$string = $fallback->($octets, $is_usv, $position);
$fallback is invoked with three arguments: $octets, $is_usv and $position.
$octets is a sequence of one or more octets containing the maximal subpart of
the ill-formed subsequence or encoded code point which can't be interchanged.
$is_usv is a boolean indicating whether or not $octets represent a encoded
Unicode scalar value. $position is a unsigned integer containing the zero
based octet position at which the error occurred within the octets provided to
"decode_utf8()". $fallback must return a character string consisting
of zero or more Unicode scalar values. Unicode scalar values consist of code
points in the range U+0000..U+D7FF and U+E000..U+10FFFF.
encode_utf8¶
$octets = encode_utf8($string);
$octets = encode_utf8($string, $fallback);
Returns an encoded representation of $string in UTF-8 encoding as an octet
string.
$fallback is an optional "CODE" reference which provides a
error-handling mechanism, allowing customization of error handling. The
default error-handling mechanism is to replace any code points which can't be
interchanged or represented in UTF-8 encoding form with REPLACEMENT CHARACTER
(U+FFFD).
$string = $fallback->($codepoint, $is_usv, $position);
$fallback is invoked with three arguments: $codepoint, $is_usv and $position.
$codepoint is a unsigned integer containing the code point which can't be
interchanged or represented in UTF-8 encoding form. $is_usv is a boolean
indicating whether or not $codepoint is a Unicode scalar value. $position is a
unsigned integer containing the zero based character position at which the
error occurred within the string provided to "encode_utf8()".
$fallback must return a character string consisting of zero or more Unicode
scalar values.Unicode scalar values consist of code points in the range
U+0000..U+D7FF and U+E000..U+10FFFF.
valid_utf8¶
$boolean = valid_utf8($octets);
Returns a boolean indicating whether or not the given $octets consist of
well-formed UTF-8 sequences.
EXPORTS¶
None by default. All functions can be exported using the ":all" tag or
individually.
DIAGNOSTICS¶
- Can't decode a wide character string
- (F) Wide character in octets.
- Can't validate a wide character string
- (F) Wide character in octets.
- Can't decode ill-formed UTF-8 octet sequence <%s> in position
%u
- (W utf8) Encountered an ill-formed UTF-8 octet sequence. <%s>
contains a hexadecimal representation of the maximal subpart of the
ill-formed subsequence.
- Can't interchange noncharacter code point U+%X in position %u
- (W utf8, nonchar) Noncharacters are code points that are permanently
reserved in the Unicode Standard for internal use. They are forbidden for
use in open interchange of Unicode text data. Noncharacters consist of the
values U+nFFFE and U+nFFFF (where n is from 0 to 10^16) and the values
U+FDD0..U+FDEF.
- Can't represent surrogate code point U+%X in position %u
- (W utf8, surrogate) Surrogate code points are designated only for
surrogate code units in the UTF-16 character encoding form. Surrogates
consist of code points in the range U+D800 to U+DFFF.
- Can't represent super code point \x{%X} in position %u
- (W utf8, non_unicode) Code points greater than U+10FFFF. Perl's extended
codespace.
- Can't decode ill-formed UTF-X octet sequence <%s> in position
%u
- (F) Encountered an ill-formed octet sequence in Perl's internal
representation of wide characters.
The sub-categories: "nonchar", "surrogate" and
"non_unicode" is only available on Perl 5.14 or greater. See
perllexwarn for available categories and hierarchies.
COMPARISON¶
Here is a summary of features for comparison with Encode's UTF-8 implementation:
- •
- Simple API which makes use of Perl's standard warning categories.
- •
- Recognizes all noncharacters regardless of Perl version
- •
- Implements Unicode's recommended practice for using U+FFFD.
- •
- Better diagnostics in warning messages
- •
- Detects and reports inconsistency in Perl's internal representation of
wide characters (UTF-X)
- •
- Preserves taintedness of decoded $octets or encoded $string
- •
- Better performance ~ 600% - 1200% (JA: 600%, AR: 700%, SV: 900%, EN:
1200%, see benchmarks directory in git repository)
It's the author's believe that this UTF-8 implementation is conformant with the
Unicode Standard Version 6.0. Any deviations from the Unicode Standard is to
be considered a bug.
SEE ALSO¶
- Encode
- <http://www.unicode.org/>
SUPPORT¶
BUGS¶
Please report any bugs by email to "bug-unicode-utf8 at rt.cpan.org",
or through the web interface at
<
http://rt.cpan.org/Public/Dist/Display.html?Name=Unicode-UTF8>. You
will be automatically notified of any progress on the request by the system.
SOURCE CODE¶
This is open source software. The code repository is available for public review
and contribution under the terms of the license.
<
http://github.com/chansen/p5-unicode-utf8>
git clone http://github.com/chansen/p5-unicode-utf8
AUTHOR¶
Christian Hansen "chansen@cpan.org"
COPYRIGHT¶
Copyright 2011-2012 by Christian Hansen.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.