10 our @EXPORT_OK = qw(rangematch);
13 my ($class, $values) = @_;
14 bless [sort map { s/[^a-z]/./g; $_ } @$values], $class;
19 my $options = shift || {};
20 my $pagesize = $options->{pagesize} || 50;
21 my $context = $options->{context } // 1 + ($pagesize >> 4);
22 my $length = $options->{length } || 4;
23 my $pages = $options->{pages } || 1 + int $#$self / $pagesize;
25 $pagesize = @$self / $pages;
28 while ($offset < @$self) {
29 my $link = substr $self->[$offset], 0, $length;
31 # take a value slightly before the current offset
32 my $before = $offset > $context ? $self->[$offset - $context] : '.';
33 # see how much of it matches the current link
35 for my $match (split //, $before) {
36 scalar $link =~ /\G\Q$match/g or last;
39 # truncate link upto where the earlier value starts to differ
40 substr($link, $trim) = '' unless $trim > length $link;
47 for my $i (0 .. $#links - 1) {
48 my ($link, $lastchar) = $links[$i + 1]->[0] =~ /(.*)(.)/;
49 $link .= $lastchar eq 'a' ? '.' : chr( ord($lastchar) - 1 )
50 unless $lastchar eq '.';
51 next if $link eq $links[$i]->[0] and $i;
52 $links[$i]->[1] = $link;
62 my ($s1, $s2) = $link =~ /([^-]*) - ([^-]*)/x
63 or return qr/^\Q$link/i;
68 $s1 le $s2 or $s1 =~ /^\Q$s2/ or return undef;
73 for my $i (0 .. length($s1) - 1) {
74 $char = substr $s1, $i, 1;
76 $next = chr( ord($char) + 1 ) if length $s1 > $i + 1;
78 if (length $s2 > $i) {
79 if ($s2 =~ /^\Q$prefix/) {
80 $last = substr $s2, $i, 1;
81 next if $char eq $last;
82 $last = chr( ord($last) - (length $s2 > 1) );
83 next if $next gt $last;
86 push @allow, $prefix."[$next-$last]";
96 for my $i (0 .. length($s2) - 1) {
97 $char = substr $s2, $i, 1;
99 if (length $s1 > $i) {
100 my $c1 = substr $s1, $i, 1;
101 if ($s1 =~ /^\Q$prefix/) {
102 next if $c1 le $char;
105 push @allow, $prefix."(?![$char-$last])"
113 if $s2 =~ /^\Q$prefix/ and $s1 le $s2
114 and not (length $s2 == 1 && length $s1 >= length $s2 && $s1 ne $s2);
117 my $match = sprintf @allow <= 1 ? '%s' : '(?:%s)', join('|', @allow);
127 List::Index - Paginate alphabetic entries by finding minimal prefixes
132 my $index = List::Index->new(\@values);
133 my @pages = $index->ranges({pagesize => 50});
134 printf '<a href="?q=%s-%s">%1$s</a> ', @$_ for @pages;
136 use List::Index 'rangematch';
137 my $limit = rangematch('b-bmq'); # matches prefix like 'baa'..'bmq'
138 @results = grep { $limit } @results;
146 L<List::Maker|List::Maker> for complex ranges of numeric lists.
150 Mischa POSLAWSKY <perl@shiar.org>
154 Copyright. All rights reserved.