Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for unicode::collate (redhat section 3pm)

Unicode::Collate(3pm)		 Perl Programmers Reference Guide	    Unicode::Collate(3pm)

NAME
       Unicode::Collate - Unicode Collation Algorithm

SYNOPSIS
	 use Unicode::Collate;

	 #construct
	 $Collator = Unicode::Collate->new(%tailoring);

	 #sort
	 @sorted = $Collator->sort(@not_sorted);

	 #compare
	 $result = $Collator->cmp($a, $b); # returns 1, 0, or -1.

DESCRIPTION
       This module is an implementation of Unicode Technical Standard #10 (UTS #10) "Unicode Col-
       lation Algorithm."

       Constructor and Tailoring

       The "new" method returns a collator object.

	  $Collator = Unicode::Collate->new(
	     UCA_Version => $UCA_Version,
	     alternate => $alternate,
	     backwards => $levelNumber, # or \@levelNumbers
	     entry => $element,
	     normalization  => $normalization_form,
	     ignoreName => qr/$ignoreName/,
	     ignoreChar => qr/$ignoreChar/,
	     katakana_before_hiragana => $bool,
	     level => $collationLevel,
	     overrideCJK => \&overrideCJK,
	     overrideHangul => \&overrideHangul,
	     preprocess => \&preprocess,
	     rearrange => \@charList,
	     table => $filename,
	     undefName => qr/$undefName/,
	     undefChar => qr/$undefChar/,
	     upper_before_lower => $bool,
	  );
	  # if %tailoring is false (i.e. empty),
	  # $Collator should do the default collation.

       UCA_Version
	   If the version number of the older UCA is given, the older behavior of that version is
	   emulated on collating.  If omitted, the return value of "UCA_Version()" is used.

	   The supported version: 8 or 9.

	   This parameter may be removed in the future version, as switching the algorithm would
	   affect the performance.

       alternate
	   -- see 3.2.2 Variable Weighting, UTS #10.

	   (the title in UCA version 8: Alternate Weighting)

	   This key allows to alternate weighting for variable collation elements, which are
	   marked with an ASTERISK in the table (NOTE: Many punction marks and symbols are vari-
	   able in allkeys.txt).

	      alternate => 'blanked', 'non-ignorable', 'shifted', or 'shift-trimmed'.

	   These names are case-insensitive.  By default (if specification is omitted), 'shifted'
	   is adopted.

	      'Blanked'        Variable elements are made ignorable at levels 1 through 3;
			       considered at the 4th level.

	      'Non-ignorable'  Variable elements are not reset to ignorable.

	      'Shifted'        Variable elements are made ignorable at levels 1 through 3
			       their level 4 weight is replaced by the old level 1 weight.
			       Level 4 weight for Non-Variable elements is 0xFFFF.

	      'Shift-Trimmed'  Same as 'shifted', but all FFFF's at the 4th level
			       are trimmed.

       backwards
	   -- see 3.1.2 French Accents, UTS #10.

		backwards => $levelNumber or \@levelNumbers

	   Weights in reverse order; ex. level 2 (diacritic ordering) in French.  If omitted,
	   forwards at all the levels.

       entry
	   -- see 3.1 Linguistic Features; 3.2.1 File Format, UTS #10.

	   Overrides a default order or defines additional collation elements

	     entry => <<'ENTRIES', # use the UCA file format
	   00E6 ; [.0861.0020.0002.00E6] [.08B1.0020.0002.00E6] # ligature <ae> as <a><e>
	   0063 0068 ; [.0893.0020.0002.0063]	   # "ch" in traditional Spanish
	   0043 0068 ; [.0893.0020.0008.0043]	   # "Ch" in traditional Spanish
	   ENTRIES

	   NOTE: The code point in the UCA file format (before ';') must be a Unicode code point,
	   but not a native code point.  So 0063 must always denote "U+0063", but not a character
	   of "\x63".

       ignoreName
       ignoreChar
	   -- see Completely Ignorable, 3.2.2 Variable Weighting, UTS #10.

	   Makes the entry in the table completely ignorable; i.e. as if the weights were zero at
	   all level.

	   E.g. when 'a' and 'e' are ignorable, 'element' is equal to 'lament' (or 'lmnt').

       level
	   -- see 4.3 Form a sort key for each string, UTS #10.

	   Set the maximum level.  Any higher levels than the specified one are ignored.

	     Level 1: alphabetic ordering
	     Level 2: diacritic ordering
	     Level 3: case ordering
	     Level 4: tie-breaking (e.g. in the case when alternate is 'shifted')

	     ex.level => 2,

	   If omitted, the maximum is the 4th.

       normalization
	   -- see 4.1 Normalize each input string, UTS #10.

	   If specified, strings are normalized before preparation of sort keys (the normaliza-
	   tion is executed after preprocess).

	   As a form name, one of the following names must be used.

	     'C'  or 'NFC'  for Normalization Form C
	     'D'  or 'NFD'  for Normalization Form D
	     'KC' or 'NFKC' for Normalization Form KC
	     'KD' or 'NFKD' for Normalization Form KD

	   If omitted, the string is put into Normalization Form D.

	   If "undef" is passed explicitly as the value for this key, any normalization is not
	   carried out (this may make tailoring easier if any normalization is not desired).

	   see CAVEAT.

       overrideCJK
	   -- see 7.1 Derived Collation Elements, UTS #10.

	   By default, mapping of CJK Unified Ideographs uses the Unicode codepoint order.  But
	   the mapping of CJK Unified Ideographs may be overrided.

	   ex. CJK Unified Ideographs in the JIS code point order.

	     overrideCJK => sub {
		 my $u = shift; 	    # get a Unicode codepoint
		 my $b = pack('n', $u);     # to UTF-16BE
		 my $s = your_unicode_to_sjis_converter($b); # convert
		 my $n = unpack('n', $s);   # convert sjis to short
		 [ $n, 0x20, 0x2, $u ];     # return the collation element
	     },

	   ex. ignores all CJK Unified Ideographs.

	     overrideCJK => sub {()}, # CODEREF returning empty list

	      # where ->eq("Pe\x{4E00}rl", "Perl") is true
	      # as U+4E00 is a CJK Unified Ideograph and to be ignorable.

	   If "undef" is passed explicitly as the value for this key, weights for CJK Unified
	   Ideographs are treated as undefined.  But assignment of weight for CJK Unified Ideo-
	   graphs in table or entry is still valid.

       overrideHangul
	   -- see 7.1 Derived Collation Elements, UTS #10.

	   By default, Hangul Syllables are decomposed into Hangul Jamo.  But the mapping of
	   Hangul Syllables may be overrided.

	   This tag works like overrideCJK, so see there for examples.

	   If you want to override the mapping of Hangul Syllables, the Normalization Forms D and
	   KD are not appropriate (they will be decomposed before overriding).

	   If "undef" is passed explicitly as the value for this key, weight for Hangul Syllables
	   is treated as undefined without decomposition into Hangul Jamo.  But definition of
	   weight for Hangul Syllables in table or entry is still valid.

       preprocess
	   -- see 5.1 Preprocessing, UTS #10.

	   If specified, the coderef is used to preprocess before the formation of sort keys.

	   ex. dropping English articles, such as "a" or "the".  Then, "the pen" is before "a
	   pencil".

		preprocess => sub {
		      my $str = shift;
		      $str =~ s/\b(?:an?|the)\s+//gi;
		      $str;
		   },

       rearrange
	   -- see 3.1.3 Rearrangement, UTS #10.

	   Characters that are not coded in logical order and to be rearranged.  By default,

	       rearrange => [ 0x0E40..0x0E44, 0x0EC0..0x0EC4 ],

	   If you want to disallow any rearrangement, pass "undef" or "[]" (a reference to an
	   empty list) as the value for this key.

	   According to the version 9 of UCA, this parameter shall not be used; but it is not
	   warned at present.

       table
	   -- see 3.2 Default Unicode Collation Element Table, UTS #10.

	   You can use another element table if desired.  The table file must be in your
	   "lib/Unicode/Collate" directory.

	   By default, the file "lib/Unicode/Collate/allkeys.txt" is used.

	   If "undef" is passed explicitly as the value for this key, no file is read (but you
	   can define collation elements via entry).

	   A typical way to define a collation element table without any file of table:

	      $onlyABC = Unicode::Collate->new(
		  table => undef,
		  entry => << 'ENTRIES',
	   0061 ; [.0101.0020.0002.0061] # LATIN SMALL LETTER A
	   0041 ; [.0101.0020.0008.0041] # LATIN CAPITAL LETTER A
	   0062 ; [.0102.0020.0002.0062] # LATIN SMALL LETTER B
	   0042 ; [.0102.0020.0008.0042] # LATIN CAPITAL LETTER B
	   0063 ; [.0103.0020.0002.0063] # LATIN SMALL LETTER C
	   0043 ; [.0103.0020.0008.0043] # LATIN CAPITAL LETTER C
	   ENTRIES
	       );

       undefName
       undefChar
	   -- see 6.3.4 Reducing the Repertoire, UTS #10.

	   Undefines the collation element as if it were unassigned in the table.  This reduces
	   the size of the table.  If an unassigned character appears in the string to be col-
	   lated, the sort key is made from its codepoint as a single-character collation ele-
	   ment, as it is greater than any other assigned collation elements (in the codepoint
	   order among the unassigned characters).  But, it'd be better to ignore characters
	   unfamiliar to you and maybe never used.

       katakana_before_hiragana
       upper_before_lower
	   -- see 6.6 Case Comparisons; 7.3.1 Tertiary Weight Table, UTS #10.

	   By default, lowercase is before uppercase and hiragana is before katakana.

	   If the tag is made true, this is reversed.

	   NOTE: These tags simplemindedly assume any lowercase/uppercase or hiragana/katakana
	   distinctions should occur in level 3, and their weights at level 3 should be same as
	   those mentioned in 7.3.1, UTS #10.  If you define your collation elements which vio-
	   lates this, these tags don't work validly.

       Methods for Collation

       "@sorted = $Collator->sort(@not_sorted)"
	   Sorts a list of strings.

       "$result = $Collator->cmp($a, $b)"
	   Returns 1 (when $a is greater than $b) or 0 (when $a is equal to $b) or -1 (when $a is
	   lesser than $b).

       "$result = $Collator->eq($a, $b)"
       "$result = $Collator->ne($a, $b)"
       "$result = $Collator->lt($a, $b)"
       "$result = $Collator->le($a, $b)"
       "$result = $Collator->gt($a, $b)"
       "$result = $Collator->ge($a, $b)"
	   They works like the same name operators as theirs.

	      eq : whether $a is equal to $b.
	      ne : whether $a is not equal to $b.
	      lt : whether $a is lesser than $b.
	      le : whether $a is lesser than $b or equal to $b.
	      gt : whether $a is greater than $b.
	      ge : whether $a is greater than $b or equal to $b.

       "$sortKey = $Collator->getSortKey($string)"
	   -- see 4.3 Form a sort key for each string, UTS #10.

	   Returns a sort key.

	   You compare the sort keys using a binary comparison and get the result of the compari-
	   son of the strings using UCA.

	      $Collator->getSortKey($a) cmp $Collator->getSortKey($b)

		 is equivalent to

	      $Collator->cmp($a, $b)

       "$sortKeyForm = $Collator->viewSortKey($string)"
	      use Unicode::Collate;
	      my $c = Unicode::Collate->new();
	      print $c->viewSortKey("Perl"),"\n";

	      # output:
	      # [0B67 0A65 0B7F 0B03 | 0020 0020 0020 0020 | 0008 0002 0002 0002 | FFFF FFFF FFFF FFFF]
	      #  Level 1	       Level 2		     Level 3		   Level 4

	       (If C<UCA_Version> is 8, the output is slightly different.)

       Methods for Searching

       DISCLAIMER: If "preprocess" or "normalization" tag is true for $Collator, calling these
       methods ("index", "match", "gmatch", "subst", "gsubst") is croaked, as the position and
       the length might differ from those on the specified string.  (And the "rearrange" tag is
       neglected.)

       The "match", "gmatch", "subst", "gsubst" methods work like "m//", "m//g", "s///", "s///g",
       respectively, but they are not aware of any pattern, but only a literal substring.

       "$position = $Collator->index($string, $substring[, $position])"
       "($position, $length) = $Collator->index($string, $substring[, $position])"
	   If $substring matches a part of $string, returns the position of the first occurrence
	   of the matching part in scalar context; in list context, returns a two-element list of
	   the position and the length of the matching part.

	   If $substring does not match any part of $string, returns "-1" in scalar context and
	   an empty list in list context.

	   e.g. you say

	     my $Collator = Unicode::Collate->new( normalization => undef, level => 1 );
						# (normalization => undef) is REQUIRED.
	     my $str = "Ich muB studieren Perl.";
	     my $sub = "MUSS";
	     my $match;
	     if (my($pos,$len) = $Collator->index($str, $sub)) {
		 $match = substr($str, $pos, $len);
	     }

	   and get "muB" in $match since "muB" is primary equal to "MUSS".

       "$match_ref = $Collator->match($string, $substring)"
       "($match)   = $Collator->match($string, $substring)"
	   If $substring matches a part of $string, in scalar context, returns a reference to the
	   first occurrence of the matching part ($match_ref is always true if matches, since
	   every reference is true); in list context, returns the first occurrence of the match-
	   ing part.

	   If $substring does not match any part of $string, returns "undef" in scalar context
	   and an empty list in list context.

	   e.g.

	       if ($match_ref = $Collator->match($str, $sub)) { # scalar context
		   print "matches [$$match_ref].\n";
	       } else {
		   print "doesn't match.\n";
	       }

		or

	       if (($match) = $Collator->match($str, $sub)) { # list context
		   print "matches [$match].\n";
	       } else {
		   print "doesn't match.\n";
	       }

       "@match = $Collator->gmatch($string, $substring)"
	   If $substring matches a part of $string, returns all the matching parts (or matching
	   count in scalar context).

	   If $substring does not match any part of $string, returns an empty list.

       "$count = $Collator->subst($string, $substring, $replacement)"
	   If $substring matches a part of $string, the first occurrence of the matching part is
	   replaced by $replacement ($string is modified) and return $count (always equals to 1).

	   $replacement can be a "CODEREF", taking the matching part as an argument, and return-
	   ing a string to replace the matching part (a bit similar to
	   "s/(..)/$coderef->($1)/e").

       "$count = $Collator->gsubst($string, $substring, $replacement)"
	   If $substring matches a part of $string, all the occurrences of the matching part is
	   replaced by $replacement ($string is modified) and return $count.

	   $replacement can be a "CODEREF", taking the matching part as an argument, and return-
	   ing a string to replace the matching part (a bit similar to
	   "s/(..)/$coderef->($1)/eg").

	   e.g.

	     my $Collator = Unicode::Collate->new( normalization => undef, level => 1 );
						# (normalization => undef) is REQUIRED.
	     my $str = "Camel ass came\x{301}l CAMEL horse cAm\0E\0L...";
	     $Collator->gsubst($str, "camel", sub { "<b>$_[0]</b>" });

	     # now $str is "<b>Camel</b> ass <b>came\x{301}l</b> <b>CAMEL</b> horse <b>cAm\0E\0L</b>...";
	     # i.e., all the camels are made bold-faced.

       Other Methods

       "%old_tailoring = $Collator->change(%new_tailoring)"
	   Change the value of specified keys and returns the changed part.

	       $Collator = Unicode::Collate->new(level => 4);

	       $Collator->eq("perl", "PERL"); # false

	       %old = $Collator->change(level => 2); # returns (level => 4).

	       $Collator->eq("perl", "PERL"); # true

	       $Collator->change(%old); # returns (level => 2).

	       $Collator->eq("perl", "PERL"); # false

	   Not all "(key,value)"s are allowed to be changed.  See also @Unicode::Col-
	   late::ChangeOK and @Unicode::Collate::ChangeNG.

	   In the scalar context, returns the modified collator (but it is not a clone from the
	   original).

	       $Collator->change(level => 2)->eq("perl", "PERL"); # true

	       $Collator->eq("perl", "PERL"); # true; now max level is 2nd.

	       $Collator->change(level => 4)->eq("perl", "PERL"); # false

       UCA_Version
	   Returns the version number of UTS #10 this module consults.

       Base_Unicode_Version
	   Returns the version number of the Unicode Standard this module is based on.

       EXPORT

       None by default.

       TODO

       Unicode::Collate has not been ported to EBCDIC.	IMHO, use of utf8::uni-
       code_to_native()/utf8::native_to_unicode() at the proper postions should allow this module
       to work on EBCDIC platform...

       CAVEAT

       Use of the "normalization" parameter requires the Unicode::Normalize module.

       If you need not it (say, in the case when you need not handle any combining characters),
       assign "normalization => undef" explicitly.

       -- see 6.5 Avoiding Normalization, UTS #10.

       Conformance Test

       The Conformance Test for the UCA is provided in <http://www.unicode.org/reports/tr10/Col-
       lationTest.html> and <http://www.unicode.org/reports/tr10/CollationTest.zip>

       For CollationTest_SHIFTED.txt, a collator via "Unicode::Collate->new( )" should be used;
       for CollationTest_NON_IGNORABLE.txt, a collator via "Unicode::Collate->new(alternate =>
       "non-ignorable", level => 3)".

       Unicode::Normalize is required to try The Conformance Test.

AUTHOR
       SADAHIRO Tomoyuki, <SADAHIRO@cpan.org>

	 http://homepage1.nifty.com/nomenclator/perl/

	 Copyright(C) 2001-2002, SADAHIRO Tomoyuki. Japan. All rights reserved.

	 This library is free software; you can redistribute it
	 and/or modify it under the same terms as Perl itself.

SEE ALSO
       http://www.unicode.org/reports/tr10/
	   Unicode Collation Algorithm - UTS #10

       http://www.unicode.org/reports/tr10/allkeys.txt
	   The Default Unicode Collation Element Table

       http://www.unicode.org/reports/tr10/CollationTest.html http://www.uni-
       code.org/reports/tr10/CollationTest.zip
	   The latest versions of the conformance test for the UCA

       http://www.unicode.org/reports/tr15/
	   Unicode Normalization Forms - UAX #15

       Unicode::Normalize

perl v5.8.0				    2002-06-01			    Unicode::Collate(3pm)


All times are GMT -4. The time now is 11:19 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password