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 Character 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 Unicode 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 positions 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 character 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 designating a Unicode character, or U+
followed by hexadecimals designating 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 unlimited): 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 character 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 character 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.unicode.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 separate 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 casespec() 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 followed 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.unicode.org/unicode/reports/tr21/
Unicode::UCD::UnicodeVersion
Unicode::UCD::UnicodeVersion() returns the version of the Unicode Character 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