X-Git-Url: http://git.shiar.nl/perl/list-index.git/blobdiff_plain/5d1c609f28d64e60c9595c9a207b8d19e823b122..1c9de66914ea7bf8525df6f5285b649c006477b9:/lib/List/Index.pm

diff --git a/lib/List/Index.pm b/lib/List/Index.pm
index 23ab261..dca0d1f 100644
--- a/lib/List/Index.pm
+++ b/lib/List/Index.pm
@@ -23,31 +23,53 @@ sub ranges {
 	my $pages    = $options->{pages   } || 1 + int $#$self / $pagesize;
 
 	$pagesize = @$self / $pages;
-	my $offset = 0;
-	my @links;
+	my $offset = $pagesize;
+	my @links = ('');
 	while ($offset < @$self) {
 		my $link = substr $self->[$offset], 0, $length;
 		if ($context) {
-			my $trim = 1;
-			my $before = $offset > $context ? $self->[$offset - $context] : '';
-			for my $match (split //, $before) {
-				scalar $link =~ /\G\Q$match/g or last;
-				$trim++;
+			{
+				# take a value slightly before the current offset
+				my $before = $offset > $context ? $self->[$offset - $context] : '.';
+				# see how much of it matches the current link
+				my $trim = 1;
+				for my $match (split //, $before) {
+					scalar $link =~ /\G\Q$match/g or last;
+					$trim++;
+				}
+				# truncate link upto where the earlier value starts to differ
+				substr($link, $trim) = '' unless $trim > length $link;
+			}
+
+			if ($offset + $context < $#$self) {
+				# take a value after the current offset
+				my $after = $self->[$offset + $context];
+				# see how much of it matches the current link
+				my $trim = 1;
+				for my $match (split //, $after) {
+					scalar $link =~ /\G\Q$match/g or last;
+					$trim++;
+				}
+				# use this link if it's shorter
+				if ($trim < length $link) {
+					$link = substr $after, 0, $trim;
+				}
 			}
-			substr($link, $trim) = '' unless $trim > length $link;
 		}
 
-		push @links, [$link];
+		push @links, $link;
 		$offset += $pagesize;
 	}
 
+	use List::MoreUtils 'uniq';
+	@links = uniq @links;
 	for my $i (0 .. $#links - 1) {
-		my ($link, $lastchar) = $links[$i + 1]->[0] =~ /(.*)(.)/;
-		$link .= $lastchar eq '.' ? 'a' : chr( ord($lastchar) - 1 )
-			unless $lastchar eq 'a';
-		$links[$i]->[1] = $link;
+		my ($link, $lastchar) = $links[$i + 1] =~ /(.*)(.)/;
+		$link .= $lastchar le 'a' ? '.' : chr( ord($lastchar) - 1 );
+		next if $link eq $links[$i] and $i;
+		$links[$i] .= '-'.$link;
 	}
-	$links[-1]->[1] = '';
+	$links[-1] .= '-';
 
 	return \@links;
 }
@@ -56,16 +78,25 @@ sub rangematch {
 	my ($link) = @_;
 	my ($s1, $s2) = $link =~ /([^-]*) - ([^-]*)/x
 		or return qr/^\Q$link/i;
+	$s1 =~ s/\.$//;
 	my @allow;
 
 	if (length $s1) {
+		if (length $s2) {
+			$s1 le $s2 or $s1 =~ /^\Q$s2/ or return undef;
+		}
+
 		my $prefix = '';
 		my $char;
 		for my $i (0 .. length($s1) - 1) {
+			my $lasti = $i == length($s1) - 1;
 			$char = substr $s1, $i, 1;
 			my $next = $char;
-			$next = chr( ord($char) + 1 ) if length $s1 > $i + 1;
+			# do not include prefix character in final range
+			$next = chr( ord($char) + 1 ) unless $lasti;
+
 			my $last = 'z';
+			next if $next gt $last;
 			if (length $s2 > $i) {
 				if ($s2 =~ /^\Q$prefix/) {
 					$last = substr $s2, $i, 1;
@@ -74,10 +105,23 @@ sub rangematch {
 					next if $next gt $last;
 				}
 			}
+
+			if ($char eq '.') {
+				if ($last eq 'z') {
+#					push @allow, $prefix if $i and $lasti;
+#					next;
+				}
+#				if ($last eq 'z') {
+#					push @allow, $prefix if $i and $lasti;
+#					next;
+#				}
+				$next = 'a';
+			}
+
 			push @allow, $prefix."[$next-$last]";
 		}
 		continue {
-			$prefix .= $char;
+			$prefix .= $char eq '.' ? '[^a-z]' : $char;
 		}
 	}
 
@@ -93,11 +137,16 @@ sub rangematch {
 					next if $c1 le $char;
 				}
 			}
-			push @allow, $prefix."(?![$char-$last])"
+
+			if ($char eq '.') {
+				next if $i < length($s2) - 1;
+			}
+
+			push @allow, $prefix.'(?!['.($char eq '.' ? 'a' : $char)."-$last])"
 				if $i or $s1 eq '';
 		}
 		continue {
-			$prefix .= $char;
+			$prefix .= $char eq '.' ? '[^a-z]' : $char;
 		}
 
 		push @allow, $prefix