Unicode::UCD(3pm) Perl Programmers Reference Guide Unicode::UCD(3pm)NAMEUnicode::UCD - Unicode character database
SYNOPSIS
use Unicode::UCD 'charinfo';
my $charinfo = charinfo($codepoint);
use Unicode::UCD 'casefold';
my $casefold = casefold(0xFB00);
use Unicode::UCD 'casespec';
my $casespec = casespec(0xFB00);
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();
my $convert_to_numeric =
Unicode::UCD::num("\N{RUMI DIGIT ONE}\N{RUMI DIGIT TWO}");
DESCRIPTION
The Unicode::UCD module offers a series of functions that provide a
simple interface to the Unicode Character Database.
code point argument
Some of the functions are called with a code point argument, which is
either a decimal or a hexadecimal scalar designating a Unicode code
point, or "U+" followed by hexadecimals designating a Unicode code
point. 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. Note that the largest code point in Unicode is U+10FFFF.
charinfo()
use Unicode::UCD 'charinfo';
my $charinfo = charinfo(0x41);
This returns information about the input "code point argument" as a
reference to a hash of fields as defined by the Unicode standard. If
the "code point argument" is not assigned in the standard (i.e., has
the general category "Cn" meaning "Unassigned") or is a non-character
(meaning it is guaranteed to never be assigned in the standard), undef
is returned.
Fields that aren't applicable to the particular code point argument
exist in the returned hash, and are empty.
The keys in the hash with the meanings of their values are:
code
the input "code point argument" expressed in hexadecimal, with
leading zeros added if necessary to make it contain at least four
hexdigits
name
name of code, all IN UPPER CASE. Some control-type code points do
not have names. This field will be empty for "Surrogate" and
"Private Use" code points, and for the others without a name, it
will contain a description enclosed in angle brackets, like
"<control>".
category
The short name of the general category of code. This will match
one of the keys in the hash returned by "general_categories()".
combining
the combining class number for code used in the Canonical Ordering
Algorithm. For Unicode 5.1, this is described in Section 3.11
"Canonical Ordering Behavior" available at
<http://www.unicode.org/versions/Unicode5.1.0/>
bidi
bidirectional type of code. This will match one of the keys in the
hash returned by "bidi_types()".
decomposition
is empty if code has no decomposition; or is one or more codes
(separated by spaces) that taken in order represent a decomposition
for code. Each has at least four hexdigits. The codes may be
preceded by a word enclosed in angle brackets then a space, like
"<compat> ", giving the type of decomposition
This decomposition may be an intermediate one whose components are
also decomposable. Use Unicode::Normalize to get the final
decomposition.
decimal
if code is a decimal digit this is its integer numeric value
digit
if code represents some other digit-like number, this is its
integer numeric value
numeric
if code represents a whole or rational number, this is its numeric
value. Rational values are expressed as a string like "1/4".
mirrored
"Y" or "N" designating if code is mirrored in bidirectional text
unicode10
name of code in the Unicode 1.0 standard if one existed for this
code point and is different from the current name
comment
As of Unicode 6.0, this is always empty.
upper
is empty if there is no single code point uppercase mapping for
code (its uppercase mapping is itself); otherwise it is that
mapping expressed as at least four hexdigits. ("casespec()" should
be used in addition to charinfo() for case mappings when the
calling program can cope with multiple code point mappings.)
lower
is empty if there is no single code point lowercase mapping for
code (its lowercase mapping is itself); otherwise it is that
mapping expressed as at least four hexdigits. ("casespec()" should
be used in addition to charinfo() for case mappings when the
calling program can cope with multiple code point mappings.)
title
is empty if there is no single code point titlecase mapping for
code (its titlecase mapping is itself); otherwise it is that
mapping expressed as at least four hexdigits. ("casespec()" should
be used in addition to charinfo() for case mappings when the
calling program can cope with multiple code point mappings.)
block
block code belongs to (used in "\p{Blk=...}"). See "Blocks versus
Scripts".
script
script code belongs to. See "Blocks versus Scripts".
Note that you cannot do (de)composition and casing based solely on the
decomposition, combining, lower, upper, and title fields; you will need
also the "compexcl()", 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 code
point belongs to, e.g. "Basic Latin". If the code point is
unassigned, this returns the block it would belong to if it were
assigned (which it may in future versions of the Unicode Standard).
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 code point
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 code point 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 code
point belongs to, e.g. "Latin", "Greek", "Han". If the code point is
unassigned, it returns undef
If supplied with an argument that can't be a code point, charscript()
tries to do the opposite and interpret the argument as a code point
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 code point script, undef is returned.
See also "Blocks versus Scripts".
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 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".
charinrange()
In addition to using the "\p{Blk=...}" and "\P{Blk=...}" 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);
general_categories()
use Unicode::UCD 'general_categories';
my $categories = general_categories();
This 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.
bidi_types()
use Unicode::UCD 'bidi_types';
my $categories = bidi_types();
This 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/> (as of Unicode 5.0.0)
compexcl()
use Unicode::UCD 'compexcl';
my $compexcl = compexcl(0x09dc);
This routine is included for backwards compatibility, but as of Perl
5.12, for most purposes it is probably more convenient to use one of
the following instead:
my $compexcl = chr(0x09dc) =~ /\p{Comp_Ex};
my $compexcl = chr(0x09dc) =~ /\p{Full_Composition_Exclusion};
or even
my $compexcl = chr(0x09dc) =~ /\p{CE};
my $compexcl = chr(0x09dc) =~ /\p{Composition_Exclusion};
The first two forms return true if the "code point argument" should not
be produced by composition normalization. The final two forms
additionally require that this fact not otherwise be determinable from
the Unicode data base for them to return true.
This routine behaves identically to the final two forms. That is, it
does not return true if the code point has a decomposition consisting
of another single code point, nor if its decomposition starts with a
code point whose combining class is non-zero. Code points that meet
either of these conditions should also not be produced by composition
normalization, which is probably why you should use the
"Full_Composition_Exclusion" property instead, as shown above.
The routine returns false otherwise.
casefold()
use Unicode::UCD 'casefold';
my $casefold = casefold(0xDF);
if (defined $casefold) {
my @full_fold_hex = split / /, $casefold->{'full'};
my $full_fold_string =
join "", map {chr(hex($_))} @full_fold_hex;
my @turkic_fold_hex =
split / /, ($casefold->{'turkic'} ne "")
? $casefold->{'turkic'}
: $casefold->{'full'};
my $turkic_fold_string =
join "", map {chr(hex($_))} @turkic_fold_hex;
}
if (defined $casefold && $casefold->{'simple'} ne "") {
my $simple_fold_hex = $casefold->{'simple'};
my $simple_fold_string = chr(hex($simple_fold_hex));
}
This returns the (almost) locale-independent case folding of the
character specified by the "code point argument".
If there is no case folding for that code point, undef is returned.
If there is a case folding for that code point, a reference to a hash
with the following fields is returned:
code
the input "code point argument" expressed in hexadecimal, with
leading zeros added if necessary to make it contain at least four
hexdigits
full
one or more codes (separated by spaces) that taken in order give
the code points for the case folding for code. Each has at least
four hexdigits.
simple
is empty, or is exactly one code with at least four hexdigits which
can be used as an alternative case folding when the calling program
cannot cope with the fold being a sequence of multiple code points.
If full is just one code point, then simple equals full. If there
is no single code point folding defined for code, then simple is
the empty string. Otherwise, it is an inferior, but still better-
than-nothing alternative folding to full.
mapping
is the same as simple if simple is not empty, and it is the same as
full otherwise. It can be considered to be the simplest possible
folding for code. It is defined primarily for backwards
compatibility.
status
is "C" (for "common") if the best possible fold is a single code
point (simple equals full equals mapping). It is "S" if there are
distinct folds, simple and full (mapping equals simple). And it is
"F" if there only a full fold (mapping equals full; simple is
empty). Note that this describes the contents of mapping. It is
defined primarily for backwards compatibility.
On versions 3.1 and earlier of Unicode, status can also be "I"
which is the same as "C" but is a special case for dotted uppercase
I and dotless lowercase i:
* If you use this "I" mapping, the result is case-insensitive,
but dotless and dotted I's are not distinguished
* If you exclude this "I" mapping, the result is not fully case-
insensitive, but dotless and dotted I's are distinguished
turkic
contains any special folding for Turkic languages. For versions of
Unicode starting with 3.2, this field is empty unless code has a
different folding in Turkic languages, in which case it is one or
more codes (separated by spaces) that taken in order give the code
points for the case folding for code in those languages. Each code
has at least four hexdigits. Note that this folding does not
maintain canonical equivalence without additional processing.
For versions of Unicode 3.1 and earlier, this field is empty unless
there is a special folding for Turkic languages, in which case
status is "I", and mapping, full, simple, and turkic are all equal.
Programs that want complete generality and the best folding results
should use the folding contained in the full field. But note that the
fold for some code points will be a sequence of multiple code points.
Programs that can't cope with the fold mapping being multiple code
points can use the folding contained in the simple field, with the loss
of some generality. In Unicode 5.1, about 7% of the defined foldings
have no single code point folding.
The mapping and status fields are provided for backwards compatibility
for existing programs. They contain the same values as in previous
versions of this function.
Locale is not completely independent. The turkic field contains
results to use when the locale is a Turkic language.
For more information about case mappings see
<http://www.unicode.org/unicode/reports/tr21>
casespec()
use Unicode::UCD 'casespec';
my $casespec = casespec(0xFB00);
This returns the potentially locale-dependent case mappings of the
"code point argument". The mappings may be longer than a single code
point (which the basic Unicode case mappings as returned by
"charinfo()" never are).
If there are no case mappings for the "code point argument", or if all
three possible mappings (lower, title and upper) result in single code
points and are locale independent and unconditional, undef is returned
(which means that the case mappings, if any, for the code point are
those returned by "charinfo()").
Otherwise, a reference to a hash giving the mappings (or a reference to
a hash of such hashes, explained below) is returned with the following
keys and their meanings:
The keys in the bottom layer hash with the meanings of their values
are:
code
the input "code point argument" expressed in hexadecimal, with
leading zeros added if necessary to make it contain at least four
hexdigits
lower
one or more codes (separated by spaces) that taken in order give
the code points for the lower case of code. Each has at least four
hexdigits.
title
one or more codes (separated by spaces) that taken in order give
the code points for the title case of code. Each has at least four
hexdigits.
upper
one or more codes (separated by spaces) that taken in order give
the code points for the upper case of code. Each has at least four
hexdigits.
condition
the conditions for the mappings to be valid. If undef, the
mappings are always valid. When defined, this field is a list of
conditions, all of which must be true for the mappings to be valid.
The list consists of one or more locales (see below) and/or
contexts (explained in the next paragraph), separated by spaces.
(Other than as used to separate elements, spaces are to be
ignored.) Case distinctions in the condition list are not
significant. Conditions preceded by "NON_" represent the negation
of the condition.
A context is one of those defined in the Unicode standard. For
Unicode 5.1, they are defined in Section 3.13 "Default Case
Operations" available at
<http://www.unicode.org/versions/Unicode5.1.0/>. These are for
context-sensitive casing.
The hash described above is returned for locale-independent casing,
where at least one of the mappings has length longer than one. If
undef is returned, the code point may have mappings, but if so, all are
length one, and are returned by "charinfo()". Note that when this
function does return a value, it will be for the complete set of
mappings for a code point, even those whose length is one.
If there are additional casing rules that apply only in certain
locales, an additional key for each will be defined in the returned
hash. Each such key will be its locale name, 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 all possible locales, see Locale::Country and
Locale::Language. (In Unicode 6.0, the only locales returned by this
function are "lt", "tr", and "az".)
Each locale key is a reference to a hash that has the form above, and
gives the casing rules for that particular locale, which take
precedence over the locale-independent ones when in that locale.
If the only casing for a code point is locale-dependent, then the
returned hash will not have any of the base keys, like "code", "upper",
etc., but will contain only locale keys.
For more information about case mappings see
<http://www.unicode.org/unicode/reports/tr21/>
namedseq()
use Unicode::UCD 'namedseq';
my $namedseq = namedseq("KATAKANA LETTER AINU P");
my @namedseq = namedseq("KATAKANA LETTER AINU P");
my %namedseq = namedseq();
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, it returns the list of the ordinals 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, it returns undef or an empty list
depending on the context.
This function only operates on officially approved (not provisional)
named sequences.
Note that as of Perl 5.14, "\N{KATAKANA LETTER AINU P}" will insert the
named sequence into double-quoted strings, and
"charnames::string_vianame("KATAKANA LETTER AINU P")" will return the
same string this function does, but will also operate on character
names that aren't named sequences, without you having to know which are
which. See charnames.
num
"num" returns the numeric value of the input Unicode string; or "undef"
if it doesn't think the entire string has a completely valid, safe
numeric value.
If the string is just one character in length, the Unicode numeric
value is returned if it has one, or "undef" otherwise. Note that this
need not be a whole number. "num("\N{TIBETAN DIGIT HALF ZERO}")", for
example returns -0.5.
If the string is more than one character, "undef" is returned unless
all its characters are decimal digits (that is they would match "\d+"),
from the same script. For example if you have an ASCII '0' and a
Bengali '3', mixed together, they aren't considered a valid number, and
"undef" is returned. A further restriction is that the digits all have
to be of the same form. A half-width digit mixed with a full-width one
will return "undef". The Arabic script has two sets of digits; "num"
will return "undef" unless all the digits in the string come from the
same set.
"num" errs on the side of safety, and there may be valid strings of
decimal digits that it doesn't recognize. Note that Unicode defines a
number of "digit" characters that aren't "decimal digit" characters.
"Decimal digits" have the property that they have a positional value,
i.e., there is a units position, a 10's position, a 100's, etc, AND
they are arranged in Unicode in blocks of 10 contiguous code points.
The Chinese digits, for example, are not in such a contiguous block,
and so Unicode doesn't view them as decimal digits, but merely digits,
and so "\d" will not match them. A single-character string containing
one of these digits will have its decimal value returned by "num", but
any longer string containing only these digits will return "undef".
Strings of multiple sub- and superscripts are not recognized as
numbers. You can use either of the compatibility decompositions in
Unicode::Normalize to change these into digits, and then call "num" on
the result.
Unicode::UCD::UnicodeVersion
This 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 ('.').
Blocks versus Scripts
The difference between a block and a script is that scripts are closer
to the linguistic notion of a set of code points required to present
languages, while block is more of an artifact of the Unicode code point
numbering and separation into blocks of (mostly) 256 code points.
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 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{Blk=...}" is used for blocks (e.g. "\p{Blk=Tibetan}" matches any of
the 256 code points in the Tibetan block).
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 v5.14.4 2012-12-19 Unicode::UCD(3pm)
