Unicode::UCD - Unicode character database
use Unicode::UCD 'charinfo';
my $charinfo = charinfo($codepoint);
use Unicode::UCD 'charprop';
my $value = charprop($codepoint, $property);
use Unicode::UCD 'charprops_all';
my $all_values_hash_ref = charprops_all($codepoint);
use Unicode::UCD 'casefold';
my $casefold = casefold($codepoint);
use Unicode::UCD 'all_casefolds';
my $all_casefolds_ref = all_casefolds();
use Unicode::UCD 'casespec';
my $casespec = casespec($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 $types = bidi_types();
use Unicode::UCD 'prop_aliases';
my @space_names = prop_aliases("space");
use Unicode::UCD 'prop_value_aliases';
my @gc_punct_names = prop_value_aliases("Gc", "Punct");
use Unicode::UCD 'prop_values';
my @all_EA_short_names = prop_values("East_Asian_Width");
use Unicode::UCD 'prop_invlist';
my @puncts = prop_invlist("gc=punctuation");
use Unicode::UCD 'prop_invmap';
my ($list_ref, $map_ref, $format, $missing)
= prop_invmap("General Category");
use Unicode::UCD 'search_invlist';
my $index = search_invlist(\@invlist, $code_point);
# The following function should be used only internally in
# implementations of the Unicode Normalization Algorithm, and there
# are better choices than it.
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}");
The Unicode::UCD module offers a series of functions that provide a simple interface to the Unicode Character Database.
Some of the functions are called with a code point argument, which is either a decimal or a hexadecimal scalar designating a code point in the platform's native character set (extended to Unicode), or a string containing U+
followed by hexadecimals designating a Unicode code point. A leading 0 will force a hexadecimal interpretation, as will a hexadecimal digit that isn't a decimal digit.
Examples:
223 # Decimal 223 in native character set
0223 # Hexadecimal 223, native (= 547 decimal)
0xDF # Hexadecimal DF, native (= 223 decimal)
'0xDF' # String form of hexadecimal (= 223 decimal)
'U+DF' # Hexadecimal DF, in Unicode's character set
(= LATIN SMALL LETTER SHARP S)
Note that the largest code point in Unicode is U+10FFFF.
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.
For results that are less "raw" than this function returns, or to get the values for any property, not just the few covered by this function, use the "charprop()" function.
The keys in the hash with the meanings of their values are:
the input native "code point argument" expressed in hexadecimal, with leading zeros added if necessary to make it contain at least four hexdigits
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>
.
The short name of the general category of code. This will match one of the keys in the hash returned by "general_categories()".
The "prop_value_aliases()" function can be used to get all the synonyms of the category name.
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/
The "prop_value_aliases()" function can be used to get all the synonyms of the combining class number.
bidirectional type of code. This will match one of the keys in the hash returned by "bidi_types()".
The "prop_value_aliases()" function can be used to get all the synonyms of the bidi type name.
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 in one step.
if code represents a decimal digit this is its integer numeric value
if code represents some other digit-like number, this is its integer numeric value
if code represents a whole or rational number, this is its numeric value. Rational values are expressed as a string like 1/4
.
Y
or N
designating if code is mirrored in bidirectional text
name of code in the Unicode 1.0 standard if one existed for this code point and is different from the current name
As of Unicode 6.0, this is always empty.
is, if non-empty, the uppercase mapping for code expressed as at least four hexdigits. This indicates that the full uppercase mapping is a single character, and is identical to the simple (single-character only) mapping. When this field is empty, it means that the simple uppercase mapping is code itself; you'll need some other means, (like "charprop()" or "casespec()" to get the full mapping.
is, if non-empty, the lowercase mapping for code expressed as at least four hexdigits. This indicates that the full lowercase mapping is a single character, and is identical to the simple (single-character only) mapping. When this field is empty, it means that the simple lowercase mapping is code itself; you'll need some other means, (like "charprop()" or "casespec()" to get the full mapping.
is, if non-empty, the titlecase mapping for code expressed as at least four hexdigits. This indicates that the full titlecase mapping is a single character, and is identical to the simple (single-character only) mapping. When this field is empty, it means that the simple titlecase mapping is code itself; you'll need some other means, (like "charprop()" or "casespec()" to get the full mapping.
the block code belongs to (used in \p{Blk=...}
). The "prop_value_aliases()" function can be used to get all the synonyms of the block name.
the script code belongs to. The "prop_value_aliases()" function can be used to get all the synonyms of the script name. Note that this is the older "Script" property value, and not the improved "Script_Extensions" value.
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 "casespec()" function and the Composition_Exclusion
property. (Or you could just use the lc(), uc(), and ucfirst() functions, and the Unicode::Normalize module.)
use Unicode::UCD 'charprop';
print charprop(0x41, "Gc"), "\n";
print charprop(0x61, "General_Category"), "\n";
prints
Lu
Ll
This returns the value of the Unicode property given by the second parameter for the "code point argument" given by the first.
The passed-in property may be specified as any of the synonyms returned by "prop_aliases()".
The return value is always a scalar, either a string or a number. For properties where there are synonyms for the values, the synonym returned by this function is the longest, most descriptive form, the one returned by "prop_value_aliases()" when called in a scalar context. Of course, you can call "prop_value_aliases()" on the result to get other synonyms.
The return values are more "cooked" than the "charinfo()" ones. For example, the "uc"
property value is the actual string containing the full uppercase mapping of the input code point. You have to go to extra trouble with charinfo
to get this value from its upper
hash element when the full mapping differs from the simple one.
Special note should be made of the return values for a few properties:
The value returned is the new-style (see "Old-style versus new-style block names").
Like "charinfo()", the result may be an intermediate decomposition whose components are also decomposable. Use Unicode::Normalize to get the final decomposition in one step.
Unlike "charinfo()", this does not include the decomposition type. Use the Decomposition_Type
property to get that.
If the input code point's name has more than one synonym, they are returned joined into a single comma-separated string.
If the result is a fraction, it is converted into a floating point number to the accuracy of your platform.
If the result is multiple script names, they are returned joined into a single comma-separated string.
When called with a property that is a Perl extension that isn't expressible in a compound form, this function currently returns undef
, as the only two possible values are true or false (1 or 0 I suppose). This behavior may change in the future, so don't write code that relies on it. Present_In
is a Perl extension that is expressible in a bipartite or compound form (for example, \p{Present_In=4.0}
), so charprop
accepts it. But Any
is a Perl extension that isn't expressible that way, so charprop
returns undef
for it. Also charprop
returns undef
for all Perl extensions that are internal-only.
use Unicode::UCD 'charprops_all';
my $%properties_of_A_hash_ref = charprops_all("U+41");
This returns a reference to a hash whose keys are all the distinct Unicode (no Perl extension) properties, and whose values are the respective values for those properties for the input "code point argument".
Each key is the property name in its longest, most descriptive form. The values are what "charprop()" would return.
This function is expensive in time and memory.
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
. The old-style block name is returned (see "Old-style versus new-style block names"). The "prop_value_aliases()" function can be used to get all the synonyms of the block name.
If the code point is unassigned, this returns the block it would belong to if it were assigned. (If the Unicode version being used is so early as to not have blocks, all code points are considered to be in No_Block
.)
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 an old-style block name. On an ASCII platform, the return value is a range set with one range: an anonymous array with a single element that consists of another anonymous array whose first element is the first code point in the block, and whose second element is the final code point in the block. On an EBCDIC platform, the first two Unicode blocks are not contiguous. Their range sets are lists containing start-of-range, end-of-range code point pairs. You can test whether a code point is in a range set using the "charinrange()" function. (To be precise, each range set contains a third array element, after the range boundary ones: the old_style block name.)
If the argument to charblock()
is not a known block, undef
is returned.
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 or the Unicode version being used is so early that it doesn't have scripts, this function returns "Unknown"
. The "prop_value_aliases()" function can be used to get all the synonyms of the script name.
Note that the Script_Extensions property is an improved version of the Script property, and you should probably be using that instead, with the "charprop()" function.
If supplied with an argument that can't be a code point, charscript() tries to do the opposite and interpret the argument as a script name. The return value is a range set: an anonymous array of arrays that contain start-of-range, end-of-range code point pairs. You can test whether a code point is in a range set using the "charinrange()" function. (To be precise, each range set contains a third array element, after the range boundary ones: the script name.)
If the charscript()
argument is not a known script, undef
is returned.
See also "Blocks versus Scripts".
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.
The names are in the old-style (see "Old-style versus new-style block names").
prop_invmap("block") can be used to get this same data in a different type of data structure.
prop_values("Block") can be used to get all the known new-style block names as a list, without the code point ranges.
See also "Blocks versus Scripts".
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.
prop_invmap("script") can be used to get this same data in a different type of data structure. Since the Script_Extensions property is an improved version of the Script property, you should instead use prop_invmap("scx").
prop_values("Script")
can be used to get all the known script names as a list, without the code point ranges.
See also "Blocks versus Scripts".
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);
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.
The "prop_values()" and "prop_value_aliases()" functions can be used as an alternative to this function; the first returning a simple list of the short category names; and the second gets all the synonyms of a given category name.
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)
The "prop_values()" and "prop_value_aliases()" functions can be used as an alternative to this function; the first returning a simple list of the short bidi type names; and the second gets all the synonyms of a given bidi type name.
WARNING: Unicode discourages the use of this function or any of the alternative mechanisms listed in this section (the documentation of compexcl()
), except internally in implementations of the Unicode Normalization Algorithm. You should be using Unicode::Normalize directly instead of these. Using these will likely lead to half-baked results.
use Unicode::UCD 'compexcl';
my $compexcl = compexcl(0x09dc);
This routine returns undef
if the Unicode version being used is so early that it doesn't have this property.
compexcl()
is included for backwards compatibility, but as of Perl 5.12 and more modern Unicode versions, 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. For the final two forms to return true, it is additionally required that this fact not otherwise be determinable from the Unicode data base.
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.
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". (Starting in Perl v5.16, the core function fc()
returns the full
mapping (described below) faster than this does, and for entire strings.)
If there is no case folding for the input 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:
the input native "code point argument" expressed in hexadecimal, with leading zeros added if necessary to make it contain at least four hexdigits
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.
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.
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.
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 is 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.
For Unicode versions between 3.1 and 3.1.1 inclusive, status can also be I
which is the same as C
but is a special case for dotted uppercase I and dotless lowercase i:
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 Unicode versions between 3.1 and 3.1.1 inclusive, 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/reports/tr21
use Unicode::UCD 'all_casefolds';
my $all_folds_ref = all_casefolds();
foreach my $char_with_casefold (sort { $a <=> $b }
keys %$all_folds_ref)
{
printf "%04X:", $char_with_casefold;
my $casefold = $all_folds_ref->{$char_with_casefold};
# Get folds for $char_with_casefold
my @full_fold_hex = split / /, $casefold->{'full'};
my $full_fold_string =
join "", map {chr(hex($_))} @full_fold_hex;
print " full=", join " ", @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;
print "; turkic=", join " ", @turkic_fold_hex;
if (defined $casefold && $casefold->{'simple'} ne "") {
my $simple_fold_hex = $casefold->{'simple'};
my $simple_fold_string = chr(hex($simple_fold_hex));
print "; simple=$simple_fold_hex";
}
print "\n";
}
This returns all the case foldings in the current version of Unicode in the form of a reference to a hash. Each key to the hash is the decimal representation of a Unicode character that has a casefold to other than itself. The casefold of a semi-colon is itself, so it isn't in the hash; likewise for a lowercase "a", but there is an entry for a capital "A". The hash value for each key is another hash, identical to what is returned by "casefold()" if called with that code point as its argument. So the value all_casefolds()->{ord("A")}'
is equivalent to casefold(ord("A"))
;
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:
the input native "code point argument" expressed in hexadecimal, with leading zeros added if necessary to make it contain at least four hexdigits
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.
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.
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.
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/reports/tr21/
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, it returns a hash with the names of all the named sequences as the keys and their 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.
use Unicode::UCD 'num';
my $val = num("123");
my $one_quarter = num("\N{VULGAR FRACTION ONE QUARTER}");
my $val = num("12a", \$valid_length); # $valid_length contains 2
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 called with an optional second parameter, a reference to a scalar, num()
will set the scalar to the length of any valid initial substring; or to 0 if none.
If the string is just one character in length, the Unicode numeric value is returned if it has one, or undef
otherwise. If the optional scalar ref is passed, it would be set to 1 if the return is valid; or 0 if the return is undef
. Note that the numeric value returned 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. In all cases, the optional scalar ref parameter is set to how long any valid initial substring of digits is; hence it will be set to the entire string length if the main return value is not undef
.
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.
use Unicode::UCD 'prop_aliases';
my ($short_name, $full_name, @other_names) = prop_aliases("space");
my $same_full_name = prop_aliases("Space"); # Scalar context
my ($same_short_name) = prop_aliases("Space"); # gets 0th element
print "The full name is $full_name\n";
print "The short name is $short_name\n";
print "The other aliases are: ", join(", ", @other_names), "\n";
prints:
The full name is White_Space
The short name is WSpace
The other aliases are: Space
Most Unicode properties have several synonymous names. Typically, there is at least a short name, convenient to type, and a long name that more fully describes the property, and hence is more easily understood.
If you know one name for a Unicode property, you can use prop_aliases
to find either the long name (when called in scalar context), or a list of all of the names, somewhat ordered so that the short name is in the 0th element, the long name in the next element, and any other synonyms are in the remaining elements, in no particular order.
The long name is returned in a form nicely capitalized, suitable for printing.
The input parameter name is loosely matched, which means that white space, hyphens, and underscores are ignored (except for the trailing underscore in the old_form grandfathered-in "L_"
, which is better written as "LC"
, and both of which mean General_Category=Cased Letter
).
If the name is unknown, undef
is returned (or an empty list in list context). Note that Perl typically recognizes property names in regular expressions with an optional "Is_
" (with or without the underscore) prefixed to them, such as \p{isgc=punct}
. This function does not recognize those in the input, returning undef
. Nor are they included in the output as possible synonyms.
prop_aliases
does know about the Perl extensions to Unicode properties, such as Any
and XPosixAlpha
, and the single form equivalents to Unicode properties such as XDigit
, Greek
, In_Greek
, and Is_Greek
. The final example demonstrates that the "Is_"
prefix is recognized for these extensions; it is needed to resolve ambiguities. For example, prop_aliases('lc')
returns the list (lc, Lowercase_Mapping)
, but prop_aliases('islc')
returns (Is_LC, Cased_Letter)
. This is because islc
is a Perl extension which is short for General_Category=Cased Letter
. The lists returned for the Perl extensions will not include the "Is_"
prefix (whether or not the input had it) unless needed to resolve ambiguities, as shown in the "islc"
example, where the returned list had one element containing "Is_"
, and the other without.
It is also possible for the reverse to happen: prop_aliases('isc')
returns the list (isc, ISO_Comment)
; whereas prop_aliases('c')
returns (C, Other)
(the latter being a Perl extension meaning General_Category=Other
. "Properties accessible through Unicode::UCD" in perluniprops lists the available forms, including which ones are discouraged from use.
Those discouraged forms are accepted as input to prop_aliases
, but are not returned in the lists. prop_aliases('isL&')
and prop_aliases('isL_')
, which are old synonyms for "Is_LC"
and should not be used in new code, are examples of this. These both return (Is_LC, Cased_Letter)
. Thus this function allows you to take a discouraged form, and find its acceptable alternatives. The same goes with single-form Block property equivalences. Only the forms that begin with "In_"
are not discouraged; if you pass prop_aliases
a discouraged form, you will get back the equivalent ones that begin with "In_"
. It will otherwise look like a new-style block name (see. "Old-style versus new-style block names").
prop_aliases
does not know about any user-defined properties, and will return undef
if called with one of those. Likewise for Perl internal properties, with the exception of "Perl_Decimal_Digit" which it does know about (and which is documented below in "prop_invmap()").
use Unicode::UCD 'prop_values';
print "AHex values are: ", join(", ", prop_values("AHex")),
"\n";
prints:
AHex values are: N, Y
Some Unicode properties have a restricted set of legal values. For example, all binary properties are restricted to just true
or false
; and there are only a few dozen possible General Categories. Use prop_values
to find out if a given property is one such, and if so, to get a list of the values:
print join ", ", prop_values("NFC_Quick_Check");
prints:
M, N, Y
If the property doesn't have such a restricted set, undef
is returned.
There are usually several synonyms for each possible value. Use "prop_value_aliases()" to access those.
Case, white space, hyphens, and underscores are ignored in the input property name (except for the trailing underscore in the old-form grandfathered-in general category property value "L_"
, which is better written as "LC"
).
If the property name is unknown, undef
is returned. Note that Perl typically recognizes property names in regular expressions with an optional "Is_
" (with or without the underscore) prefixed to them, such as \p{isgc=punct}
. This function does not recognize those in the property parameter, returning undef
.
For the block property, new-style block names are returned (see "Old-style versus new-style block names").
prop_values
does not know about any user-defined properties, and will return undef
if called with one of those.
use Unicode::UCD 'prop_value_aliases';
my ($short_name, $full_name, @other_names)
= prop_value_aliases("Gc", "Punct");
my $same_full_name = prop_value_aliases("Gc", "P"); # Scalar cntxt
my ($same_short_name) = prop_value_aliases("Gc", "P"); # gets 0th
# element
print "The full name is $full_name\n";
print "The short name is $short_name\n";
print "The other aliases are: ", join(", ", @other_names), "\n";
prints:
The full name is Punctuation
The short name is P
The other aliases are: Punct
Some Unicode properties have a restricted set of legal values. For example, all binary properties are restricted to just true
or false
; and there are only a few dozen possible General Categories.
You can use "prop_values()" to find out if a given property is one which has a restricted set of values, and if so, what those values are. But usually each value actually has several synonyms. For example, in Unicode binary properties, truth can be represented by any of the strings "Y", "Yes", "T", or "True"; and the General Category "Punctuation" by that string, or "Punct", or simply "P".
Like property names, there is typically at least a short name for each such property-value, and a long name. If you know any name of the property-value (which you can get by "prop_values()", you can use prop_value_aliases
() to get the long name (when called in scalar context), or a list of all the names, with the short name in the 0th element, the long name in the next element, and any other synonyms in the remaining elements, in no particular order, except that any all-numeric synonyms will be last.
The long name is returned in a form nicely capitalized, suitable for printing.
Case, white space, hyphens, and underscores are ignored in the input parameters (except for the trailing underscore in the old-form grandfathered-in general category property value "L_"
, which is better written as "LC"
).
If either name is unknown, undef
is returned. Note that Perl typically recognizes property names in regular expressions with an optional "Is_
" (with or without the underscore) prefixed to them, such as \p{isgc=punct}
. This function does not recognize those in the property parameter, returning undef
.
If called with a property that doesn't have synonyms for its values, it returns the input value, possibly normalized with capitalization and underscores, but not necessarily checking that the input value is valid.
For the block property, new-style block names are returned (see