Unicode::UCD - Unicode character database
- 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 qw(general_categories bidi_types);
- my $categories = general_categories();
- my $types = bidi_types();
- use Unicode::UCD 'compexcl';
- my $compexcl = compexcl($codepoint);
- use Unicode::UCD 'namedseq';
- my $namedseq = namedseq($named_sequence_name);
- my $unicode_version = Unicode::UCD::UnicodeVersion();
The Unicode::UCD module offers a simple interface to the Unicode Character Database.
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 type
- 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.
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 character block, undef is returned.
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 character script, undef is returned.
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() returns a reference to 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.
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/
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).
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.
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():
The general_categories() returns a reference to a hash which has short
general category names (such as Lu
, Nd
, Zs
, S
) as keys and long
names (such as UppercaseLetter
, DecimalNumber
, SpaceSeparator
,
Symbol
) as values. The hash is reversible in case you need to go
from the long names to the short names. The general category is the
one returned from charinfo() under the category
key.
The bidi_types() returns a reference to a hash which has the short
bidi (bidirectional) type names (such as L
, R
) as keys and long
names (such as Left-to-Right
, Right-to-Left
) as values. The
hash is reversible in case you need to go from the long names to the
short names. The bidi type is the one returned from charinfo()
under the bidi
key. For the exact meaning of the various bidi classes
the Unicode TR9 is recommended reading:
http://www.unicode.org/reports/tr9/tr9-17.html
(as of Unicode 5.0.0)
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.
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/
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/
If used with a single argument in a scalar context, returns the string
consisting of the code points of the named sequence, or undef if no
named sequence by that name exists. If used with a single argument in
a list context, returns list of the code points. If used with no
arguments in a list context, returns a hash with the names of the
named sequences as the keys and the named sequences as strings as
the values. Otherwise, returns undef or empty list depending
on the context.
(New from Unicode 4.1.0)
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 ('.'
).
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.
Does not yet support EBCDIC platforms.
Jarkko Hietaniemi