package Unicode::Collate; BEGIN { if (ord("A") == 193) { die "Unicode::Collate not ported to EBCDIC\n"; } } use 5.006; use strict; use warnings; use Carp; use File::Spec; require Exporter; our $VERSION = '0.12'; our $PACKAGE = __PACKAGE__; our @ISA = qw(Exporter); our %EXPORT_TAGS = (); our @EXPORT_OK = (); our @EXPORT = (); (our $Path = $INC{'Unicode/Collate.pm'}) =~ s/\.pm$//; our $KeyFile = "allkeys.txt"; our $UNICODE_VERSION; eval { require Unicode::UCD }; unless ($@) { $UNICODE_VERSION = Unicode::UCD::UnicodeVersion(); } else { # XXX, Perl 5.6.1 my($f, $fh); foreach my $d (@INC) { use File::Spec; $f = File::Spec->catfile($d, "unicode", "Unicode.301"); if (open($fh, $f)) { $UNICODE_VERSION = '3.0.1'; close $fh; last; } } } our $getCombinClass; # coderef for combining class from Unicode::Normalize use constant Min2 => 0x20; # minimum weight at level 2 use constant Min3 => 0x02; # minimum weight at level 3 use constant UNDEFINED => 0xFF80; # special value for undefined CE's our $DefaultRearrange = [ 0x0E40..0x0E44, 0x0EC0..0x0EC4 ]; sub UCA_Version { "8.0" } sub Base_Unicode_Version { $UNICODE_VERSION || 'unknown' } ## ## constructor ## sub new { my $class = shift; my $self = bless { @_ }, $class; # alternate lowercased $self->{alternate} = ! exists $self->{alternate} ? 'shifted' : lc($self->{alternate}); croak "$PACKAGE unknown alternate tag name: $self->{alternate}" unless $self->{alternate} eq 'blanked' || $self->{alternate} eq 'non-ignorable' || $self->{alternate} eq 'shifted' || $self->{alternate} eq 'shift-trimmed'; # collation level $self->{level} ||= 4; croak "Illegal level lower than 1 (passed $self->{level})." if $self->{level} < 1; croak "A level higher than 4 (passed $self->{level}) is not supported." if 4 < $self->{level}; # overrideHangul and -CJK # If true: CODEREF used; '': default; undef: derived elements $self->{overrideHangul} = '' if ! exists $self->{overrideHangul}; $self->{overrideCJK} = '' if ! exists $self->{overrideCJK}; # normalization form $self->{normalization} = 'D' if ! exists $self->{normalization}; $self->{UNF} = undef; if (defined $self->{normalization}) { eval { require Unicode::Normalize }; croak "Unicode/Normalize.pm is required to normalize strings: $@" if $@; Unicode::Normalize->import(); $getCombinClass = \&Unicode::Normalize::getCombinClass if ! $getCombinClass; $self->{UNF} = $self->{normalization} =~ /^(?:NF)?C$/ ? \&NFC : $self->{normalization} =~ /^(?:NF)?D$/ ? \&NFD : $self->{normalization} =~ /^(?:NF)?KC$/ ? \&NFKC : $self->{normalization} =~ /^(?:NF)?KD$/ ? \&NFKD : croak "$PACKAGE unknown normalization form name: " . $self->{normalization}; } # Open a table file. # If undef is passed explicitly, no file is read. $self->{table} = $KeyFile if ! exists $self->{table}; $self->read_table if defined $self->{table}; if ($self->{entry}) { $self->parseEntry($_) foreach split /\n/, $self->{entry}; } # backwards $self->{backwards} ||= [ ]; $self->{backwards} = [ $self->{backwards} ] if ! ref $self->{backwards}; # rearrange $self->{rearrange} = $DefaultRearrange if ! exists $self->{rearrange}; $self->{rearrange} = [] if ! defined $self->{rearrange}; croak "$PACKAGE: A list for rearrangement must be store in an ARRAYREF" if ! ref $self->{rearrange}; # keys of $self->{rearrangeHash} are $self->{rearrange}. $self->{rearrangeHash} = undef; if (@{ $self->{rearrange} }) { @{ $self->{rearrangeHash} }{ @{ $self->{rearrange} } } = (); } return $self; } sub read_table { my $self = shift; my $file = $self->{table} ne '' ? $self->{table} : $KeyFile; my $filepath = File::Spec->catfile($Path, $file); open my $fk, "<$filepath" or croak "File does not exist at $filepath"; while (<$fk>) { next if /^\s*#/; if (/^\s*\@/) { if (/^\@version\s*(\S*)/) { $self->{version} ||= $1; } elsif (/^\@alternate\s+(.*)/) { $self->{alternate} ||= $1; } elsif (/^\@backwards\s+(.*)/) { push @{ $self->{backwards} }, $1; } elsif (/^\@rearrange\s+(.*)/) { push @{ $self->{rearrange} }, _getHexArray($1); } next; } $self->parseEntry($_); } close $fk; } ## ## get $line, parse it, and write an entry in $self ## sub parseEntry { my $self = shift; my $line = shift; my($name, $ele, @key); return if $line !~ /^\s*[0-9A-Fa-f]/; # removes comment and gets name $name = $1 if $line =~ s/[#%]\s*(.*)//; return if defined $self->{undefName} && $name =~ /$self->{undefName}/; # gets element my($e, $k) = split /;/, $line; croak "Wrong Entry: must be separated by ';' from " if ! $k; my @e = _getHexArray($e); $ele = pack('U*', @e); return if defined $self->{undefChar} && $ele =~ /$self->{undefChar}/; # get sort key if (defined $self->{ignoreName} && $name =~ /$self->{ignoreName}/ || defined $self->{ignoreChar} && $ele =~ /$self->{ignoreChar}/) { $self->{entries}{$ele} = $self->{ignored}{$ele} = 1; } else { my $combining = 1; # primary = 0, secondary != 0; foreach my $arr ($k =~ /\[([^\[\]]+)\]/g) { # SPACEs allowed my $var = $arr =~ /\*/; # exactly /^\*/ but be lenient. push @key, $self->altCE($var, _getHexArray($arr)); $combining = 0 unless $key[-1][0] == 0 && $key[-1][1] != 0; } $self->{entries}{$ele} = \@key; $self->{combining}{$ele} = 1 if $combining; } $self->{maxlength}{ord $ele} = scalar @e if @e > 1; } ## ## arrayref CE = altCE(bool variable?, list[num] weights) ## sub altCE { my $self = shift; my $var = shift; my @c = @_; $self->{alternate} eq 'blanked' ? $var ? [0,0,0,$c[3]] : \@c : $self->{alternate} eq 'non-ignorable' ? \@c : $self->{alternate} eq 'shifted' ? $var ? [0,0,0,$c[0] ] : [ @c[0..2], $c[0]+$c[1]+$c[2] ? 0xFFFF : 0 ] : $self->{alternate} eq 'shift-trimmed' ? $var ? [0,0,0,$c[0] ] : [ @c[0..2], 0 ] : croak "$PACKAGE unknown alternate name: $self->{alternate}"; } ## ## string hex_sortkey = splitCE(string arg) ## sub viewSortKey { my $self = shift; my $key = $self->getSortKey(@_); my $view = join " ", map sprintf("%04X", $_), unpack 'n*', $key; $view =~ s/ ?0000 ?/|/g; return "[$view]"; } ## ## list[strings] elements = splitCE(string arg) ## sub splitCE { my $self = shift; my $code = $self->{preprocess}; my $norm = $self->{UNF}; my $ent = $self->{entries}; my $max = $self->{maxlength}; my $reH = $self->{rearrangeHash}; my $str = ref $code ? &$code(shift) : shift; $str = &$norm($str) if ref $norm; my @src = unpack('U*', $str); my @buf; # rearrangement if ($reH) { for (my $i = 0; $i < @src; $i++) { if (exists $reH->{ $src[$i] } && $i + 1 < @src) { ($src[$i], $src[$i+1]) = ($src[$i+1], $src[$i]); $i++; } } } for (my $i = 0; $i < @src; $i++) { my $ch; my $u = $src[$i]; # non-characters next unless defined $u; next if $u < 0 || 0x10FFFF < $u # out of range || (0xD800 <= $u && $u <= 0xDFFF); # unpaired surrogates my $four = $u & 0xFFFF; next if $four == 0xFFFE || $four == 0xFFFF; if ($max->{$u}) { # contract for (my $j = $max->{$u}; $j >= 1; $j--) { next unless $i+$j-1 < @src; $ch = pack 'U*', @src[$i .. $i+$j-1]; $i += $j-1, last if $ent->{$ch}; } } else { $ch = pack('U', $u); } # with Combining Char (UTS#10, 4.2.1), here requires Unicode::Normalize. if ($getCombinClass && defined $ch) { for (my $j = $i+1; $j < @src; $j++) { next unless defined $src[$j]; last unless $getCombinClass->( $src[$j] ); my $comb = pack 'U', $src[$j]; next if ! $ent->{ $ch.$comb }; $ch .= $comb; $src[$j] = undef; } } push @buf, $ch; } wantarray ? @buf : \@buf; } ## ## list[arrayrefs] weight = getWt(string element) ## sub getWt { my $self = shift; my $ch = shift; my $ent = $self->{entries}; my $ign = $self->{ignored}; my $cjk = $self->{overrideCJK}; my $hang = $self->{overrideHangul}; return if !defined $ch || $ign->{$ch}; # ignored return @{ $ent->{$ch} } if $ent->{$ch}; my $u = unpack('U', $ch); if (0xAC00 <= $u && $u <= 0xD7A3) { # is_Hangul return $hang ? &$hang($u) : defined $hang ? map({ my $v = $_; my $ar = $ent->{pack('U', $v)}; $ar ? @$ar : map($self->altCE(0,@$_), _derivCE($v)); } _decompHangul($u)) : map($self->altCE(0,@$_), _derivCE($u)); } elsif (0x3400 <= $u && $u <= 0x4DB5 || 0x4E00 <= $u && $u <= 0x9FA5 || 0x20000 <= $u && $u <= 0x2A6D6) { # is_CJK return $cjk ? &$cjk($u) : defined $cjk && $u <= 0xFFFF ? $self->altCE(0, ($u, 0x20, 0x02, $u)) : map($self->altCE(0,@$_), _derivCE($u)); } else { return map($self->altCE(0,@$_), _derivCE($u)); } } ## ## int = index(string, substring) ## sub index { my $self = shift; my $lev = $self->{level}; my $comb = $self->{combining}; my $str = $self->splitCE(shift); my $sub = $self->splitCE(shift); return wantarray ? (0,0) : 0 if ! @$sub; return wantarray ? () : -1 if ! @$str; my @subWt = grep _ignorableAtLevel($_,$lev), map $self->getWt($_), @$sub; my(@strWt,@strPt); my $count = 0; for (my $i = 0; $i < @$str; $i++) { my $go_ahead = 0; my @tmp = grep _ignorableAtLevel($_,$lev), $self->getWt($str->[$i]); $go_ahead += length $str->[$i]; # /*XXX*/ still broken. # index("e\x{300}", "e") should be 'no match' at level 2 or higher # as "e\x{300}" is a *single* grapheme cluster and not equal to "e". # go ahead as far as we find a combining character; while ($i + 1 < @$str && (! defined $str->[$i+1] || $comb->{ $str->[$i+1] }) ) { $i++; $go_ahead += length $str->[$i]; next if ! defined $str->[$i]; push @tmp, grep _ignorableAtLevel($_,$lev), $self->getWt($str->[$i]); } push @strWt, @tmp; push @strPt, ($count) x @tmp; $count += $go_ahead; while (@strWt >= @subWt) { if (_eqArray(\@strWt, \@subWt, $lev)) { my $pos = $strPt[0]; return wantarray ? ($pos, $count-$pos) : $pos; } shift @strWt; shift @strPt; } } return wantarray ? () : -1; } ## ## bool _eqArray(arrayref, arrayref, level) ## sub _eqArray($$$) { my $a = shift; # length $a >= length $b; my $b = shift; my $lev = shift; for my $v (0..$lev-1) { for my $c (0..@$b-1){ return if $a->[$c][$v] != $b->[$c][$v]; } } return 1; } ## ## bool _ignorableAtLevel(CE, level) ## sub _ignorableAtLevel($$) { my $ce = shift; return unless defined $ce; my $lv = shift; return ! grep { ! $ce->[$_] } 0..$lv-1; } ## ## string sortkey = getSortKey(string arg) ## sub getSortKey { my $self = shift; my $lev = $self->{level}; my $rCE = $self->splitCE(shift); # get an arrayref # weight arrays my @buf = grep defined(), map $self->getWt($_), @$rCE; # make sort key my @ret = ([],[],[],[]); foreach my $v (0..$lev-1) { foreach my $b (@buf) { push @{ $ret[$v] }, $b->[$v] if $b->[$v]; } } foreach (@{ $self->{backwards} }) { my $v = $_ - 1; @{ $ret[$v] } = reverse @{ $ret[$v] }; } # modification of tertiary weights if ($self->{upper_before_lower}) { foreach (@{ $ret[2] }) { if (0x8 <= $_ && $_ <= 0xC) { $_ -= 6 } # lower elsif (0x2 <= $_ && $_ <= 0x6) { $_ += 6 } # upper elsif ($_ == 0x1C) { $_ += 1 } # square upper elsif ($_ == 0x1D) { $_ -= 1 } # square lower } } if ($self->{katakana_before_hiragana}) { foreach (@{ $ret[2] }) { if (0x0F <= $_ && $_ <= 0x13) { $_ -= 2 } # katakana elsif (0x0D <= $_ && $_ <= 0x0E) { $_ += 5 } # hiragana } } join "\0\0", map pack('n*', @$_), @ret; } ## ## int compare = cmp(string a, string b) ## sub cmp { $_[0]->getSortKey($_[1]) cmp $_[0]->getSortKey($_[2]) } sub eq { $_[0]->getSortKey($_[1]) eq $_[0]->getSortKey($_[2]) } sub ne { $_[0]->getSortKey($_[1]) ne $_[0]->getSortKey($_[2]) } sub lt { $_[0]->getSortKey($_[1]) lt $_[0]->getSortKey($_[2]) } sub le { $_[0]->getSortKey($_[1]) le $_[0]->getSortKey($_[2]) } sub gt { $_[0]->getSortKey($_[1]) gt $_[0]->getSortKey($_[2]) } sub ge { $_[0]->getSortKey($_[1]) ge $_[0]->getSortKey($_[2]) } ## ## list[strings] sorted = sort(list[strings] arg) ## sub sort { my $obj = shift; return map { $_->[1] } sort{ $a->[0] cmp $b->[0] } map [ $obj->getSortKey($_), $_ ], @_; } ## ## list[arrayrefs] CE = _derivCE(int codepoint) ## sub _derivCE { my $code = shift; my $a = UNDEFINED + ($code >> 15); # ok my $b = ($code & 0x7FFF) | 0x8000; # ok # my $a = 0xFFC2 + ($code >> 15); # ng # my $b = $code & 0x7FFF | 0x1000; # ng $b ? ([$a,2,1,$code],[$b,0,0,$code]) : [$a,2,1,$code]; } ## ## "hhhh hhhh hhhh" to (dddd, dddd, dddd) ## sub _getHexArray { map hex, $_[0] =~ /([0-9a-fA-F]+)/g } # # $code must be in Hangul syllable. # Check it before you enter here. # sub _decompHangul { my $code = shift; my $SIndex = $code - 0xAC00; my $LIndex = int( $SIndex / 588); my $VIndex = int(($SIndex % 588) / 28); my $TIndex = $SIndex % 28; return ( 0x1100 + $LIndex, 0x1161 + $VIndex, $TIndex ? (0x11A7 + $TIndex) : (), ); } 1; __END__ =head1 NAME Unicode::Collate - Unicode Collation Algorithm =head1 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. =head1 DESCRIPTION =head2 Constructor and Tailoring The C method returns a collator object. $Collator = Unicode::Collate->new( 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. =over 4 =item alternate -- see 3.2.2 Alternate Weighting, UTR #10. 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 variable in F). 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 ignorable at levels 1 through 3; considered at the 4th level. 'Non-ignorable' Variable elements are not reset to ignorable. 'Shifted' Variable elements are 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. =item backwards -- see 3.1.2 French Accents, UTR #10. backwards => $levelNumber or \@levelNumbers Weights in reverse order; ex. level 2 (diacritic ordering) in French. If omitted, forwards at all the levels. =item entry -- see 3.1 Linguistic Features; 3.2.1 File Format, UTR #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 as 0063 0068 ; [.0893.0020.0002.0063] # "ch" in traditional Spanish 0043 0068 ; [.0893.0020.0008.0043] # "Ch" in traditional Spanish ENTRIES =item ignoreName =item ignoreChar -- see Completely Ignorable, 3.2.2 Alternate Weighting, UTR #10. Makes the entry in the table ignorable. If a collation element is ignorable, it is ignored as if the element had been deleted from there. E.g. when 'a' and 'e' are ignorable, 'element' is equal to 'lament' (or 'lmnt'). =item level -- see 4.3 Form a sort key for each string, UTR #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. =item normalization -- see 4.1 Normalize each input string, UTR #10. If specified, strings are normalized before preparation of sort keys (the normalization 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 C 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 B. =item overrideCJK -- see 7.1 Derived Collation Elements, UTR #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 C 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 Ideographs in table or L is still valid. =item overrideHangul -- see 7.1 Derived Collation Elements, UTR #10. By default, Hangul Syllables are decomposed into Hangul Jamo. But the mapping of Hangul Syllables may be overrided. This tag works like L, 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 C 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 L is still valid. =item preprocess -- see 5.1 Preprocessing, UTR #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; }, =item rearrange -- see 3.1.3 Rearrangement, UTR #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 C or C<[]> (a reference to an empty list) as the value for this key. =item table -- see 3.2 Default Unicode Collation Element Table, UTR #10. You can use another element table if desired. The table file must be in your C directory. By default, the file C is used. If C is passed explicitly as the value for this key, no file is read (but you can define collation elements via L). 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 ); =item undefName =item undefChar -- see 6.3.4 Reducing the Repertoire, UTR #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 collated, the sort key is made from its codepoint as a single-character collation element, 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. =item katakana_before_hiragana =item upper_before_lower -- see 6.6 Case Comparisons; 7.3.1 Tertiary Weight Table, UTR #10. By default, lowercase is before uppercase and hiragana is before katakana. If the tag is made true, this is reversed. B: 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, UTR #10. If you define your collation elements which violates this, these tags doesn't work validly. =back =head2 Methods for Collation =over 4 =item C<@sorted = $Collator-Esort(@not_sorted)> Sorts a list of strings. =item C<$result = $Collator-Ecmp($a, $b)> Returns 1 (when C<$a> is greater than C<$b>) or 0 (when C<$a> is equal to C<$b>) or -1 (when C<$a> is lesser than C<$b>). =item C<$result = $Collator-Eeq($a, $b)> =item C<$result = $Collator-Ene($a, $b)> =item C<$result = $Collator-Elt($a, $b)> =item C<$result = $Collator-Ele($a, $b)> =item C<$result = $Collator-Egt($a, $b)> =item C<$result = $Collator-Ege($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 $b. =item C<$sortKey = $Collator-EgetSortKey($string)> -- see 4.3 Form a sort key for each string, UTR #10. Returns a sort key. You compare the sort keys using a binary comparison and get the result of the comparison of the strings using UCA. $Collator->getSortKey($a) cmp $Collator->getSortKey($b) is equivalent to $Collator->cmp($a, $b) =item C<$sortKeyForm = $Collator-EviewSortKey($string)> Returns a string formalized to display a sort key. Weights are enclosed with C<'['> and C<']'> and level boundaries are denoted by C<'|'>. use Unicode::Collate; my $c = Unicode::Collate->new(); print $c->viewSortKey("Perl"),"\n"; # output: # [09B3 08B1 09CB 094F|0020 0020 0020 0020|0008 0002 0002 0002|FFFF FFFF FFFF FFFF] # Level 1 Level 2 Level 3 Level 4 =item C<$position = $Collator-Eindex($string, $substring)> =item C<($position, $length) = $Collator-Eindex($string, $substring)> -- see 6.8 Searching, UTR #10. If C<$substring> matches a part of C<$string>, returns the position of the first occurrence of the matching part in scalar context; in list context, returns a two-element list of the position and the length of the matching part. B that the length of the matching part may differ from the length of C<$substring>. B that the position and the length are counted on the string after the process of preprocess, normalization, and rearrangement. Therefore, in case the specified string is not binary equal to the preprocessed/normalized/rearranged string, the position and the length may differ form those on the specified string. But it is guaranteed that, if matched, it returns a non-negative value as C<$position>. If C<$substring> does not match any part of C<$string>, returns C<-1> in scalar context and an empty list in list context. e.g. you say my $Collator = Unicode::Collate->new( normalization => undef, level => 1 ); my $str = "Ich mu\x{00DF} studieren."; my $sub = "m\x{00FC}ss"; my $match; if (my($pos,$len) = $Collator->index($str, $sub)) { $match = substr($str, $pos, $len); } and get C<"mu\x{00DF}"> in C<$match> since C<"mu>E<223>C<"> is primary equal to C<"m>E<252>C. =back =head2 Other Methods =over 4 =item UCA_Version Returns the version number of Unicode Technical Standard 10 this module consults. =item Base_Unicode_Version Returns the version number of the Unicode Standard this module is based on. =back =head2 EXPORT None by default. =head2 TODO Unicode::Collate has not been ported to EBCDIC. The code mostly would work just fine but a decision needs to be made: how the module should work in EBCDIC? Should the low 256 characters be understood as Unicode or as EBCDIC code points? Should one be chosen or should there be a way to do either? Or should such translation be left outside the module for the user to do, for example by using Encode::from_to()? (or utf8::unicode_to_native()/utf8::native_to_unicode()?) =head2 CAVEAT Use of the C parameter requires the B module. If you need not it (say, in the case when you need not handle any combining characters), assign C undef> explicitly. -- see 6.5 Avoiding Normalization, UTR #10. =head2 BUGS C is an experimental method and its return value may be unreliable. The correct implementation for C must be based on Locale-Sensitive Support: Level 3 in UTR #18, F. See also 4.2 Locale-Dependent Graphemes in UTR #18. =head1 AUTHOR SADAHIRO Tomoyuki, ESADAHIRO@cpan.orgE 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. =head1 SEE ALSO =over 4 =item http://www.unicode.org/unicode/reports/tr10/ Unicode Collation Algorithm - UTR #10 =item http://www.unicode.org/unicode/reports/tr10/allkeys.txt The Default Unicode Collation Element Table =item http://www.unicode.org/unicode/reports/tr15/ Unicode Normalization Forms - UAX #15 =item http://www.unicode.org/unicode/reports/tr18 Unicode Regular Expression Guidelines - UTR #18 =item L =back =cut