Unicode::UCD(3pm) Perl Programmers Reference Guide Unicode::UCD(3pm)
NAME
Unicode::UCD - Unicode character database
SYNOPSIS
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}");
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 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.
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.
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:
code
the input native "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()".
The "prop_value_aliases()" function can be used to get all the
synonyms of the category name.
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/>;
The "prop_value_aliases()" function can be used to get all the
synonyms of the combining class number.
bidi
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.
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 in one step.
decimal
if code represents 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, 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.
lower
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.
title
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.
block
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.
See "Blocks versus Scripts".
script
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.
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 "casespec()" function and the "Composition_Exclusion"
property. (Or you could just use the lc(), uc(), and ucfirst()
functions, and the Unicode::Normalize module.)
charprop()
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:
Block
The value returned is the new-style (see "Old-style versus new-
style block names").
Decomposition_Mapping
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.
Name_Alias
If the input code point's name has more than one synonym, they are
returned joined into a single comma-separated string.
Numeric_Value
If the result is a fraction, it is converted into a floating point
number to the accuracy of your platform.
Script_Extensions
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.
charprops_all()
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.
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". 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.
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 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".
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.
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".
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.
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".
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.
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.
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)
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.
compexcl()
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.
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". (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:
code
the input native "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 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:
* 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 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/unicode/reports/tr21>;
all_casefolds()
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"))";
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 native "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, 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.
num()
use Unicode::UCD 'num';
my $val = num("123");
my $one_quarter = num("\N{VULGAR FRACTION 1/4}");
"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.
prop_aliases()
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()").
prop_values()
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.
prop_value_aliases()
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 "Old-
style versus new-style block names").
To find the synonyms for single-forms, such as "\p{Any}", use
"prop_aliases()" instead.
"prop_value_aliases" does not know about any user-defined properties,
and will return "undef" if called with one of those.
prop_invlist()
"prop_invlist" returns an inversion list (described below) that defines
all the code points for the binary Unicode property (or
"property=value" pair) given by the input parameter string:
use feature 'say';
use Unicode::UCD 'prop_invlist';
say join ", ", prop_invlist("Any");
prints:
0, 1114112
If the input is unknown "undef" is returned in scalar context; an
empty-list in list context. If the input is known, the number of
elements in the list is returned if called in scalar context.
perluniprops gives the list of properties that this function accepts,
as well as all the possible forms for them (including with the optional
"Is_" prefixes). (Except this function doesn't accept any Perl-
internal properties, some of which are listed there.) This function
uses the same loose or tighter matching rules for resolving the input
property's name as is done for regular expressions. These are also
specified in perluniprops. Examples of using the "property=value" form
are:
say join ", ", prop_invlist("Script_Extensions=Shavian");
prints:
66640, 66688
say join ", ", prop_invlist("ASCII_Hex_Digit=No");
prints:
0, 48, 58, 65, 71, 97, 103
say join ", ", prop_invlist("ASCII_Hex_Digit=Yes");
prints:
48, 58, 65, 71, 97, 103
Inversion lists are a compact way of specifying Unicode property-value
definitions. The 0th item in the list is the lowest code point that
has the property-value. The next item (item [1]) is the lowest code
point beyond that one that does NOT have the property-value. And the
next item beyond that ([2]) is the lowest code point beyond that one
that does have the property-value, and so on. Put another way, each
element in the list gives the beginning of a range that has the
property-value (for even numbered elements), or doesn't have the
property-value (for odd numbered elements). The name for this data
structure stems from the fact that each element in the list toggles (or
inverts) whether the corresponding range is or isn't on the list.
In the final example above, the first ASCII Hex digit is code point 48,
the character "0", and all code points from it through 57 (a "9") are
ASCII hex digits. Code points 58 through 64 aren't, but 65 (an "A")
through 70 (an "F") are, as are 97 ("a") through 102 ("f"). 103 starts
a range of code points that aren't ASCII hex digits. That range
extends to infinity, which on your computer can be found in the
variable $Unicode::UCD::MAX_CP. (This variable is as close to infinity
as Perl can get on your platform, and may be too high for some
operations to work; you may wish to use a smaller number for your
purposes.)
Note that the inversion lists returned by this function can possibly
include non-Unicode code points, that is anything above 0x10FFFF.
Unicode properties are not defined on such code points. You might wish
to change the output to not include these. Simply add 0x110000 at the
end of the non-empty returned list if it isn't already that value; and
pop that value if it is; like:
my @list = prop_invlist("foo");
if (@list) {
if ($list[-1] == 0x110000) {
pop @list; # Defeat the turning on for above Unicode
}
else {
push @list, 0x110000; # Turn off for above Unicode
}
}
It is a simple matter to expand out an inversion list to a full list of
all code points that have the property-value:
my @invlist = prop_invlist($property_name);
die "empty" unless @invlist;
my @full_list;
for (my $i = 0; $i < @invlist; $i += 2) {
my $upper = ($i + 1) < @invlist
? $invlist[$i+1] - 1 # In range
: $Unicode::UCD::MAX_CP; # To infinity.
for my $j ($invlist[$i] .. $upper) {
push @full_list, $j;
}
}
"prop_invlist" does not know about any user-defined nor Perl internal-
only properties, and will return "undef" if called with one of those.
The "search_invlist()" function is provided for finding a code point
within an inversion list.
prop_invmap()
use Unicode::UCD 'prop_invmap';
my ($list_ref, $map_ref, $format, $default)
= prop_invmap("General Category");
"prop_invmap" is used to get the complete mapping definition for a
property, in the form of an inversion map. An inversion map consists
of two parallel arrays. One is an ordered list of code points that
mark range beginnings, and the other gives the value (or mapping) that
all code points in the corresponding range have.
"prop_invmap" is called with the name of the desired property. The
name is loosely matched, meaning that differences in case, white-space,
hyphens, and underscores are not meaningful (except for the trailing
underscore in the old-form grandfathered-in property "L_", which is
better written as "LC", or even better, "Gc=LC").
Many Unicode properties have more than one name (or alias).
"prop_invmap" understands all of these, including Perl extensions to
them. Ambiguities are resolved as described above for "prop_aliases()"
(except if a property has both a complete mapping, and a binary "Y"/"N"
mapping, then specifying the property name prefixed by "is" causes the
binary one to be returned). The Perl internal property
"Perl_Decimal_Digit, described below, is also accepted. An empty list
is returned if the property name is unknown. See "Properties
accessible through Unicode::UCD" in perluniprops for the properties
acceptable as inputs to this function.
It is a fatal error to call this function except in list context.
In addition to the two arrays that form the inversion map,
"prop_invmap" returns two other values; one is a scalar that gives some
details as to the format of the entries of the map array; the other is
a default value, useful in maps whose format name begins with the
letter "a", as described below in its subsection; and for specialized
purposes, such as converting to another data structure, described at
the end of this main section.
This means that "prop_invmap" returns a 4 element list. For example,
my ($blocks_ranges_ref, $blocks_maps_ref, $format, $default)
= prop_invmap("Block");
In this call, the two arrays will be populated as shown below (for
Unicode 6.0):
Index @blocks_ranges @blocks_maps
0 0x0000 Basic Latin
1 0x0080 Latin-1 Supplement
2 0x0100 Latin Extended-A
3 0x0180 Latin Extended-B
4 0x0250 IPA Extensions
5 0x02B0 Spacing Modifier Letters
6 0x0300 Combining Diacritical Marks
7 0x0370 Greek and Coptic
8 0x0400 Cyrillic
...
233 0x2B820 No_Block
234 0x2F800 CJK Compatibility Ideographs Supplement
235 0x2FA20 No_Block
236 0xE0000 Tags
237 0xE0080 No_Block
238 0xE0100 Variation Selectors Supplement
239 0xE01F0 No_Block
240 0xF0000 Supplementary Private Use Area-A
241 0x100000 Supplementary Private Use Area-B
242 0x110000 No_Block
The first line (with Index [0]) means that the value for code point 0
is "Basic Latin". The entry "0x0080" in the @blocks_ranges column in
the second line means that the value from the first line, "Basic
Latin", extends to all code points in the range from 0 up to but not
including 0x0080, that is, through 127. In other words, the code
points from 0 to 127 are all in the "Basic Latin" block. Similarly,
all code points in the range from 0x0080 up to (but not including)
0x0100 are in the block named "Latin-1 Supplement", etc. (Notice that
the return is the old-style block names; see "Old-style versus new-
style block names").
The final line (with Index [242]) means that the value for all code
points above the legal Unicode maximum code point have the value
"No_Block", which is the term Unicode uses for a non-existing block.
The arrays completely specify the mappings for all possible code
points. The final element in an inversion map returned by this
function will always be for the range that consists of all the code
points that aren't legal Unicode, but that are expressible on the
platform. (That is, it starts with code point 0x110000, the first code
point above the legal Unicode maximum, and extends to infinity.) The
value for that range will be the same that any typical unassigned code
point has for the specified property. (Certain unassigned code points
are not "typical"; for example the non-character code points, or those
in blocks that are to be written right-to-left. The above-Unicode
range's value is not based on these atypical code points.) It could be
argued that, instead of treating these as unassigned Unicode code
points, the value for this range should be "undef". If you wish, you
can change the returned arrays accordingly.
The maps for almost all properties are simple scalars that should be
interpreted as-is. These values are those given in the Unicode-
supplied data files, which may be inconsistent as to capitalization and
as to which synonym for a property-value is given. The results may be
normalized by using the "prop_value_aliases()" function.
There are exceptions to the simple scalar maps. Some properties have
some elements in their map list that are themselves lists of scalars;
and some special strings are returned that are not to be interpreted
as-is. Element [2] (placed into $format in the example above) of the
returned four element list tells you if the map has any of these
special elements or not, as follows:
"s" means all the elements of the map array are simple scalars, with no
special elements. Almost all properties are like this, like the
"block" example above.
"sl"
means that some of the map array elements have the form given by
"s", and the rest are lists of scalars. For example, here is a
portion of the output of calling "prop_invmap"() with the "Script
Extensions" property:
@scripts_ranges @scripts_maps
...
0x0953 Devanagari
0x0964 [ Bengali, Devanagari, Gurumukhi, Oriya ]
0x0966 Devanagari
0x0970 Common
Here, the code points 0x964 and 0x965 are both used in Bengali,
Devanagari, Gurmukhi, and Oriya, but no other scripts.
The Name_Alias property is also of this form. But each scalar
consists of two components: 1) the name, and 2) the type of alias
this is. They are separated by a colon and a space. In Unicode
6.1, there are several alias types:
"correction"
indicates that the name is a corrected form for the original
name (which remains valid) for the same code point.
"control"
adds a new name for a control character.
"alternate"
is an alternate name for a character
"figment"
is a name for a character that has been documented but was
never in any actual standard.
"abbreviation"
is a common abbreviation for a character
The lists are ordered (roughly) so the most preferred names come
before less preferred ones.
For example,
@aliases_ranges @alias_maps
...
0x009E [ 'PRIVACY MESSAGE: control', 'PM: abbreviation' ]
0x009F [ 'APPLICATION PROGRAM COMMAND: control',
'APC: abbreviation'
]
0x00A0 'NBSP: abbreviation'
0x00A1 ""
0x00AD 'SHY: abbreviation'
0x00AE ""
0x01A2 'LATIN CAPITAL LETTER GHA: correction'
0x01A3 'LATIN SMALL LETTER GHA: correction'
0x01A4 ""
...
A map to the empty string means that there is no alias defined for
the code point.
"a" is like "s" in that all the map array elements are scalars, but
here they are restricted to all being integers, and some have to be
adjusted (hence the name "a") to get the correct result. For
example, in:
my ($uppers_ranges_ref, $uppers_maps_ref, $format, $default)
= prop_invmap("Simple_Uppercase_Mapping");
the returned arrays look like this:
@$uppers_ranges_ref @$uppers_maps_ref Note
0 0
97 65 'a' maps to 'A', b => B ...
123 0
181 924 MICRO SIGN => Greek Cap MU
182 0
...
and $default is 0.
Let's start with the second line. It says that the uppercase of
code point 97 is 65; or "uc("a")" == "A". But the line is for the
entire range of code points 97 through 122. To get the mapping for
any code point in this range, you take the offset it has from the
beginning code point of the range, and add that to the mapping for
that first code point. So, the mapping for 122 ("z") is derived by
taking the offset of 122 from 97 (=25) and adding that to 65,
yielding 90 ("z"). Likewise for everything in between.
Requiring this simple adjustment allows the returned arrays to be
significantly smaller than otherwise, up to a factor of 10,
speeding up searching through them.
Ranges that map to $default, "0", behave somewhat differently. For
these, each code point maps to itself. So, in the first line in
the example, "ord(uc(chr(0)))" is 0, "ord(uc(chr(1)))" is 1, ..
"ord(uc(chr(96)))" is 96.
"al"
means that some of the map array elements have the form given by
"a", and the rest are ordered lists of code points. For example,
in:
my ($uppers_ranges_ref, $uppers_maps_ref, $format, $default)
= prop_invmap("Uppercase_Mapping");
the returned arrays look like this:
@$uppers_ranges_ref @$uppers_maps_ref
0 0
97 65
123 0
181 924
182 0
...
0x0149 [ 0x02BC 0x004E ]
0x014A 0
0x014B 330
...
This is the full Uppercase_Mapping property (as opposed to the
Simple_Uppercase_Mapping given in the example for format "a"). The
only difference between the two in the ranges shown is that the
code point at 0x0149 (LATIN SMALL LETTER N PRECEDED BY APOSTROPHE)
maps to a string of two characters, 0x02BC (MODIFIER LETTER
APOSTROPHE) followed by 0x004E (LATIN CAPITAL LETTER N).
No adjustments are needed to entries that are references to arrays;
each such entry will have exactly one element in its range, so the
offset is always 0.
The fourth (index [3]) element ($default) in the list returned for
this format is 0.
"ae"
This is like "a", but some elements are the empty string, and
should not be adjusted. The one internal Perl property accessible
by "prop_invmap" is of this type: "Perl_Decimal_Digit" returns an
inversion map which gives the numeric values that are represented
by the Unicode decimal digit characters. Characters that don't
represent decimal digits map to the empty string, like so:
@digits @values
0x0000 ""
0x0030 0
0x003A: ""
0x0660: 0
0x066A: ""
0x06F0: 0
0x06FA: ""
0x07C0: 0
0x07CA: ""
0x0966: 0
...
This means that the code points from 0 to 0x2F do not represent
decimal digits; the code point 0x30 (DIGIT ZERO) represents 0;
code point 0x31, (DIGIT ONE), represents 0+1-0 = 1; ... code point
0x39, (DIGIT NINE), represents 0+9-0 = 9; ... code points 0x3A
through 0x65F do not represent decimal digits; 0x660 (ARABIC-INDIC
DIGIT ZERO), represents 0; ... 0x07C1 (NKO DIGIT ONE), represents
0+1-0 = 1 ...
The fourth (index [3]) element ($default) in the list returned for
this format is the empty string.
"ale"
is a combination of the "al" type and the "ae" type. Some of the
map array elements have the forms given by "al", and the rest are
the empty string. The property "NFKC_Casefold" has this form. An
example slice is:
@$ranges_ref @$maps_ref Note
...
0x00AA 97 FEMININE ORDINAL INDICATOR => 'a'
0x00AB 0
0x00AD SOFT HYPHEN => ""
0x00AE 0
0x00AF [ 0x0020, 0x0304 ] MACRON => SPACE . COMBINING MACRON
0x00B0 0
...
The fourth (index [3]) element ($default) in the list returned for
this format is 0.
"ar"
means that all the elements of the map array are either rational
numbers or the string "NaN", meaning "Not a Number". A rational
number is either an integer, or two integers separated by a solidus
("/"). The second integer represents the denominator of the
division implied by the solidus, and is actually always positive,
so it is guaranteed not to be 0 and to not be signed. When the
element is a plain integer (without the solidus), it may need to be
adjusted to get the correct value by adding the offset, just as
other "a" properties. No adjustment is needed for fractions, as
the range is guaranteed to have just a single element, and so the
offset is always 0.
If you want to convert the returned map to entirely scalar numbers,
you can use something like this:
my ($invlist_ref, $invmap_ref, $format) = prop_invmap($property);
if ($format && $format eq "ar") {
map { $_ = eval $_ if $_ ne 'NaN' } @$map_ref;
}
Here's some entries from the output of the property "Nv", which has
format "ar".
@numerics_ranges @numerics_maps Note
0x00 "NaN"
0x30 0 DIGIT 0 .. DIGIT 9
0x3A "NaN"
0xB2 2 SUPERSCRIPTs 2 and 3
0xB4 "NaN"
0xB9 1 SUPERSCRIPT 1
0xBA "NaN"
0xBC 1/4 VULGAR FRACTION 1/4
0xBD 1/2 VULGAR FRACTION 1/2
0xBE 3/4 VULGAR FRACTION 3/4
0xBF "NaN"
0x660 0 ARABIC-INDIC DIGIT ZERO .. NINE
0x66A "NaN"
The fourth (index [3]) element ($default) in the list returned for
this format is "NaN".
"n" means the Name property. All the elements of the map array are
simple scalars, but some of them contain special strings that
require more work to get the actual name.
Entries such as:
CJK UNIFIED IDEOGRAPH-<code point>
mean that the name for the code point is "CJK UNIFIED IDEOGRAPH-"
with the code point (expressed in hexadecimal) appended to it, like
"CJK UNIFIED IDEOGRAPH-3403" (similarly for
"CJK COMPATIBILITY IDEOGRAPH-<code point>").
Also, entries like
<hangul syllable>
means that the name is algorithmically calculated. This is easily
done by the function "charnames::viacode(code)" in charnames.
Note that for control characters ("Gc=cc"), Unicode's data files
have the string ""<control>"", but the real name of each of these
characters is the empty string. This function returns that real
name, the empty string. (There are names for these characters, but
they are considered aliases, not the Name property name, and are
contained in the "Name_Alias" property.)
"ad"
means the Decomposition_Mapping property. This property is like
"al" properties, except that one of the scalar elements is of the
form:
<hangul syllable>
This signifies that this entry should be replaced by the
decompositions for all the code points whose decomposition is
algorithmically calculated. (All of them are currently in one
range and no others outside the range are likely to ever be added
to Unicode; the "n" format has this same entry.) These can be
generated via the function Unicode::Normalize::NFD().
Note that the mapping is the one that is specified in the Unicode
data files, and to get the final decomposition, it may need to be
applied recursively. Unicode in fact discourages use of this
property except internally in implementations of the Unicode
Normalization Algorithm.
The fourth (index [3]) element ($default) in the list returned for
this format is 0.
Note that a format begins with the letter "a" if and only the property
it is for requires adjustments by adding the offsets in multi-element
ranges. For all these properties, an entry should be adjusted only if
the map is a scalar which is an integer. That is, it must match the
regular expression:
/ ^ -? \d+ $ /xa
Further, the first element in a range never needs adjustment, as the
adjustment would be just adding 0.
A binary search such as that provided by "search_invlist()", can be
used to quickly find a code point in the inversion list, and hence its
corresponding mapping.
The final, fourth element (index [3], assigned to $default in the
"block" example) in the four element list returned by this function is
used with the "a" format types; it may also be useful for applications
that wish to convert the returned inversion map data structure into
some other, such as a hash. It gives the mapping that most code points
map to under the property. If you establish the convention that any
code point not explicitly listed in your data structure maps to this
value, you can potentially make your data structure much smaller. As
you construct your data structure from the one returned by this
function, simply ignore those ranges that map to this value. For
example, to convert to the data structure searchable by
"charinrange()", you can follow this recipe for properties that don't
require adjustments:
my ($list_ref, $map_ref, $format, $default) = prop_invmap($property);
my @range_list;
# Look at each element in the list, but the -2 is needed because we
# look at $i+1 in the loop, and the final element is guaranteed to map
# to $default by prop_invmap(), so we would skip it anyway.
for my $i (0 .. @$list_ref - 2) {
next if $map_ref->[$i] eq $default;
push @range_list, [ $list_ref->[$i],
$list_ref->[$i+1],
$map_ref->[$i]
];
}
print charinrange(\@range_list, $code_point), "\n";
With this, "charinrange()" will return "undef" if its input code point
maps to $default. You can avoid this by omitting the "next" statement,
and adding a line after the loop to handle the final element of the
inversion map.
Similarly, this recipe can be used for properties that do require
adjustments:
for my $i (0 .. @$list_ref - 2) {
next if $map_ref->[$i] eq $default;
# prop_invmap() guarantees that if the mapping is to an array, the
# range has just one element, so no need to worry about adjustments.
if (ref $map_ref->[$i]) {
push @range_list,
[ $list_ref->[$i], $list_ref->[$i], $map_ref->[$i] ];
}
else { # Otherwise each element is actually mapped to a separate
# value, so the range has to be split into single code point
# ranges.
my $adjustment = 0;
# For each code point that gets mapped to something...
for my $j ($list_ref->[$i] .. $list_ref->[$i+1] -1 ) {
# ... add a range consisting of just it mapping to the
# original plus the adjustment, which is incremented for the
# next time through the loop, as the offset increases by 1
# for each element in the range
push @range_list,
[ $j, $j, $map_ref->[$i] + $adjustment++ ];
}
}
}
Note that the inversion maps returned for the "Case_Folding" and
"Simple_Case_Folding" properties do not include the Turkic-locale
mappings. Use "casefold()" for these.
"prop_invmap" does not know about any user-defined properties, and will
return "undef" if called with one of those.
The returned values for the Perl extension properties, such as "Any"
and "Greek" are somewhat misleading. The values are either "Y" or
""N"". All Unicode properties are bipartite, so you can actually use
the "Y" or ""N"" in a Perl regular expression for these, like
"qr/\p{ID_Start=Y/}" or "qr/\p{Upper=N/}". But the Perl extensions
aren't specified this way, only like "/qr/\p{Any}", etc. You can't
actually use the "Y" and ""N"" in them.
Getting every available name
Instead of reading the Unicode Database directly from files, as you
were able to do for a long time, you are encouraged to use the supplied
functions. So, instead of reading "Name.pl" - which may disappear
without notice in the future - directly, as with
my (%name, %cp);
for (split m/\s*\n/ => do "unicore/Name.pl") {
my ($cp, $name) = split m/\t/ => $_;
$cp{$name} = $cp;
$name{$cp} = $name unless $cp =~ m/ /;
}
You ought to use "prop_invmap()" like this:
my (%name, %cp, %cps, $n);
# All codepoints
foreach my $cat (qw( Name Name_Alias )) {
my ($codepoints, $names, $format, $default) = prop_invmap($cat);
# $format => "n", $default => ""
foreach my $i (0 .. @$codepoints - 2) {
my ($cp, $n) = ($codepoints->[$i], $names->[$i]);
# If $n is a ref, the same codepoint has multiple names
foreach my $name (ref $n ? @$n : $n) {
$name{$cp} //= $name;
$cp{$name} //= $cp;
}
}
}
# Named sequences
{ my %ns = namedseq();
foreach my $name (sort { $ns{$a} cmp $ns{$b} } keys %ns) {
$cp{$name} //= [ map { ord } split "" => $ns{$name} ];
}
}
search_invlist()
use Unicode::UCD qw(prop_invmap prop_invlist);
use Unicode::UCD 'search_invlist';
my @invlist = prop_invlist($property_name);
print $code_point, ((search_invlist(\@invlist, $code_point) // -1) % 2)
? " isn't"
: " is",
" in $property_name\n";
my ($blocks_ranges_ref, $blocks_map_ref) = prop_invmap("Block");
my $index = search_invlist($blocks_ranges_ref, $code_point);
print "$code_point is in block ", $blocks_map_ref->[$index], "\n";
"search_invlist" is used to search an inversion list returned by
"prop_invlist" or "prop_invmap" for a particular "code point argument".
"undef" is returned if the code point is not found in the inversion
list (this happens only when it is not a legal "code point argument",
or is less than the list's first element). A warning is raised in the
first instance.
Otherwise, it returns the index into the list of the range that
contains the code point.; that is, find "i" such that
list[i]<= code_point < list[i+1].
As explained in "prop_invlist()", whether a code point is in the list
or not depends on if the index is even (in) or odd (not in). And as
explained in "prop_invmap()", the index is used with the returned
parallel array to find the mapping.
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 represent
languages, while block is more of an artifact of the Unicode code point
numbering and separation into blocks of consecutive code points (so far
the size of a block is some multiple of 16, like 128 or 256).
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 nor 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).
Old-style versus new-style block names
Unicode publishes the names of blocks in two different styles, though
the two are equivalent under Unicode's loose matching rules.
The original style uses blanks and hyphens in the block names (except
for "No_Block"), like so:
Miscellaneous Mathematical Symbols-B
The newer style replaces these with underscores, like this:
Miscellaneous_Mathematical_Symbols_B
This newer style is consistent with the values of other Unicode
properties. To preserve backward compatibility, all the functions in
Unicode::UCD that return block names (except as noted) return the old-
style ones. "prop_value_aliases()" returns the new-style and can be
used to convert from old-style to new-style:
my $new_style = prop_values_aliases("block", $old_style);
Perl also has single-form extensions that refer to blocks,
"In_Cyrillic", meaning "Block=Cyrillic". These have always been
written in the new style.
To convert from new-style to old-style, follow this recipe:
$old_style = charblock((prop_invlist("block=$new_style"))[0]);
(which finds the range of code points in the block using
"prop_invlist", gets the lower end of the range (0th element) and then
looks up the old name for its block using "charblock").
Note that starting in Unicode 6.1, many of the block names have shorter
synonyms. These are always given in the new style.
Use with older Unicode versions
The functions in this module work as well as can be expected when used
on earlier Unicode versions. But, obviously, they use the available
data from that Unicode version. For example, if the Unicode version
predates the definition of the script property (Unicode 3.1), then any
function that deals with scripts is going to return "undef" for the
script portion of the return value.
AUTHOR
Jarkko Hietaniemi. Now maintained by perl5 porters.
perl v5.26.3 2018-03-23 Unicode::UCD(3pm)
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