Unicode::UCD
Unicode::UCD(3) Perl Programmers Reference Guide Unicode::UCD(3)
NAME
Unicode::UCD - Unicode character database
SYNOPSIS
use Unicode::UCD 'charinfo';
my $charinfo = charinfo($codepoint);
use Unicode::UCD 'charblock';
my $charblock = charblock($codepoint);
use Unicode::UCD 'charscript';
my $charscript = charscript($codepoint);
use Unicode::UCD 'charblocks';
my $charblocks = charblocks();
use Unicode::UCD 'charscripts';
my %charscripts = charscripts();
use Unicode::UCD qw(charscript charinrange);
my $range = charscript($script);
print "looks like $script\n" if charinrange($range, $codepoint);
use Unicode::UCD 'compexcl';
my $compexcl = compexcl($codepoint);
my $unicode_version = Unicode::UCD::UnicodeVersion();
DESCRIPTION
The Unicode::UCD module offers a simple interface to the Unicode Char-
acter Database.
charinfo
use Unicode::UCD 'charinfo';
my $charinfo = charinfo(0x41);
charinfo() returns a reference to a hash that has the following fields
as defined by the Unicode standard:
key
code code point with at least four hexdigits
name name of the character IN UPPER CASE
category general category of the character
combining classes used in the Canonical Ordering Algorithm
bidi bidirectional category
decomposition character decomposition mapping
decimal if decimal digit this is the integer numeric value
digit if digit this is the numeric value
numeric if numeric is the integer or rational numeric value
mirrored if mirrored in bidirectional text
unicode10 Unicode 1.0 name if existed and different
comment ISO 10646 comment field
upper uppercase equivalent mapping
lower lowercase equivalent mapping
title titlecase equivalent mapping
block block the character belongs to (used in \p{In...})
script script the character belongs to
If no match is found, a reference to an empty hash is returned.
The "block" property is the same as returned by charinfo(). It is not
defined in the Unicode Character Database proper (Chapter 4 of the Uni-
code 3.0 Standard, aka TUS3) but instead in an auxiliary database
(Chapter 14 of TUS3). Similarly for the "script" property.
Note that you cannot do (de)composition and casing based solely on the
above "decomposition" and "lower", "upper", "title", properties, you
will need also the compexcl(), casefold(), and casespec() functions.
charblock
use Unicode::UCD 'charblock';
my $charblock = charblock(0x41);
my $charblock = charblock(1234);
my $charblock = charblock("0x263a");
my $charblock = charblock("U+263a");
my $range = charblock('Armenian');
With a code point argument charblock() returns the block the character
belongs to, e.g. "Basic Latin". Note that not all the character posi-
tions within all blocks are defined.
See also "Blocks versus Scripts".
If supplied with an argument that can't be a code point, charblock()
tries to do the opposite and interpret the argument as a character
block. The return value is a range: an anonymous list of lists that
contain start-of-range, end-of-range code point pairs. You can test
whether a code point is in a range using the "charinrange" function. If
the argument is not a known charater block, "undef" is returned.
charscript
use Unicode::UCD 'charscript';
my $charscript = charscript(0x41);
my $charscript = charscript(1234);
my $charscript = charscript("U+263a");
my $range = charscript('Thai');
With a code point argument charscript() returns the script the charac-
ter belongs to, e.g. "Latin", "Greek", "Han".
See also "Blocks versus Scripts".
If supplied with an argument that can't be a code point, charscript()
tries to do the opposite and interpret the argument as a character
script. The return value is a range: an anonymous list of lists that
contain start-of-range, end-of-range code point pairs. You can test
whether a code point is in a range using the "charinrange" function. If
the argument is not a known charater script, "undef" is returned.
charblocks
use Unicode::UCD 'charblocks';
my $charblocks = charblocks();
charblocks() returns a reference to a hash with the known block names
as the keys, and the code point ranges (see "charblock") as the values.
See also "Blocks versus Scripts".
charscripts
use Unicode::UCD 'charscripts';
my %charscripts = charscripts();
charscripts() returns a hash with the known script names as the keys,
and the code point ranges (see "charscript") as the values.
See also "Blocks versus Scripts".
Blocks versus Scripts
The difference between a block and a script is that scripts are closer
to the linguistic notion of a set of characters required to present
languages, while block is more of an artifact of the Unicode character
numbering and separation into blocks of (mostly) 256 characters.
For example the Latin script is spread over several blocks, such as
"Basic Latin", "Latin 1 Supplement", "Latin Extended-A", and "Latin
Extended-B". On the other hand, the Latin script does not contain all
the characters of the "Basic Latin" block (also known as the ASCII): it
includes only the letters, and not, for example, the digits or the
punctuation.
For blocks see http://www.unicode.org/Public/UNIDATA/Blocks.txt
For scripts see UTR #24: http://www.unicode.org/unicode/reports/tr24/
Matching Scripts and Blocks
Scripts are matched with the regular-expression construct "\p{...}"
(e.g. "\p{Tibetan}" matches characters of the Tibetan script), while
"\p{In...}" is used for blocks (e.g. "\p{InTibetan}" matches any of the
256 code points in the Tibetan block).
Code Point Arguments
A code point argument is either a decimal or a hexadecimal scalar des-
ignating a Unicode character, or "U+" followed by hexadecimals desig-
nating a Unicode character. In other words, if you want a code point
to be interpreted as a hexadecimal number, you must prefix it with
either "0x" or "U+", because a string like e.g. 123 will be interpreted
as a decimal code point. Also note that Unicode is not limited to 16
bits (the number of Unicode characters is open-ended, in theory unlim-
ited): you may have more than 4 hexdigits.
charinrange
In addition to using the "\p{In...}" and "\P{In...}" constructs, you
can also test whether a code point is in the range as returned by
"charblock" and "charscript" or as the values of the hash returned by
"charblocks" and "charscripts" by using charinrange():
use Unicode::UCD qw(charscript charinrange);
$range = charscript('Hiragana');
print "looks like hiragana\n" if charinrange($range, $codepoint);
compexcl
use Unicode::UCD 'compexcl';
my $compexcl = compexcl("09dc");
The compexcl() returns the composition exclusion (that is, if the char-
acter should not be produced during a precomposition) of the character
specified by a code point argument.
If there is a composition exclusion for the character, true is
returned. Otherwise, false is returned.
casefold
use Unicode::UCD 'casefold';
my $casefold = casefold("00DF");
The casefold() returns the locale-independent case folding of the char-
acter specified by a code point argument.
If there is a case folding for that character, a reference to a hash
with the following fields is returned:
key
code code point with at least four hexdigits
status "C", "F", "S", or "I"
mapping one or more codes separated by spaces
The meaning of the status is as follows:
C common case folding, common mappings shared
by both simple and full mappings
F full case folding, mappings that cause strings
to grow in length. Multiple characters are separated
by spaces
S simple case folding, mappings to single characters
where different from F
I special case for dotted uppercase I and
dotless lowercase i
- If this mapping is included, the result is
case-insensitive, but dotless and dotted I's
are not distinguished
- If this mapping is excluded, the result is not
fully case-insensitive, but dotless and dotted
I's are distinguished
If there is no case folding for that character, "undef" is returned.
For more information about case mappings see http://www.uni-
code.org/unicode/reports/tr21/
casespec
use Unicode::UCD 'casespec';
my $casespec = casespec("FB00");
The casespec() returns the potentially locale-dependent case mapping of
the character specified by a code point argument. The mapping may
change the length of the string (which the basic Unicode case mappings
as returned by charinfo() never do).
If there is a case folding for that character, a reference to a hash
with the following fields is returned:
key
code code point with at least four hexdigits
lower lowercase
title titlecase
upper uppercase
condition condition list (may be undef)
The "condition" is optional. Where present, it consists of one or more
locales or contexts, separated by spaces (other than as used to sepa-
rate elements, spaces are to be ignored). A condition list overrides
the normal behavior if all of the listed conditions are true. Case
distinctions in the condition list are not significant. Conditions
preceded by "NON_" represent the negation of the condition.
Note that when there are multiple case folding definitions for a single
code point because of different locales, the value returned by cas-
espec() is a hash reference which has the locales as the keys and hash
references as described above as the values.
A locale is defined as a 2-letter ISO 3166 country code, possibly fol-
lowed by a "_" and a 2-letter ISO language code (possibly followed by a
"_" and a variant code). You can find the lists of those codes, see
Locale::Country and Locale::Language.
A context is one of the following choices:
FINAL The letter is not followed by a letter of
general category L (e.g. Ll, Lt, Lu, Lm, or Lo)
MODERN The mapping is only used for modern text
AFTER_i The last base character was "i" (U+0069)
For more information about case mappings see http://www.uni-
code.org/unicode/reports/tr21/
Unicode::UCD::UnicodeVersion
Unicode::UCD::UnicodeVersion() returns the version of the Unicode Char-
acter Database, in other words, the version of the Unicode standard the
database implements. The version is a string of numbers delimited by
dots ('.').
Implementation Note
The first use of charinfo() opens a read-only filehandle to the Unicode
Character Database (the database is included in the Perl distribution).
The filehandle is then kept open for further queries. In other words,
if you are wondering where one of your filehandles went, that's where.
BUGS
Does not yet support EBCDIC platforms.
AUTHOR
Jarkko Hietaniemi
perl v5.8.6 2001-09-21 Unicode::UCD(3)
