- plan tests => 4;
- my $index = List::Index->new([qw(
- baa1 baa2 baa3 baaa bbc cbc daaa ea eaaa zed
- )]) or return;
- is_deeply($index->ranges({pagesize => 2, context => 0}), [
- qw(-baa. baa.-bbb bbc-daa. daaa-eaa. eaaa-)
- ], 'no context');
- is_deeply($index->ranges({pagesize => 2}), [
- qw(-a b c d e-)
- ], 'default context'); # context should be 1
- is_deeply($index->ranges({pagesize => 2, context => 2}), [
- qw(-a b-c d e-)
- ], 'overlap'); # first item equals second due to large context
- is_deeply($index->ranges({pagesize => 2, context => 0, length => 1}), [
- qw(-a b-c d e-)
- ], 'single char');
-
- #pp($index->ranges({pagesize => 2, context => 2, length => 1}));
+ plan tests => 9;
+ my @data = qw(
+ kkeg kl km kmlu knsy koxb kpeo kuaa kuab kuac
+ kuapa kuq kur kux kzb lc lg lgu lgua lguc
+ lguq lgur lgus lgx lka lkq lks lln llq llx
+ );
+ my $index = List::Index->new({ pagesize => 10 }) or return;
+
+ is_deeply(
+ $index->ranges(\@data, { context => 0, length => 5 }),
+ # ranges should match offsets exactly
+ [qw(-kuap. kuapa-lgup lguq-)],
+ 'no context'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 0 }),
+ # default length limits to 4 chars
+ [qw(-kuao kuap-lgup lguq-)],
+ 'default length'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 1 }),
+ # lookbehinds aren't shorter (kuac<kuap, lguc<lguq)
+ # 'kuap' can advance to 'kuq'
+ [qw(-kup kuq-lgup lguq-)],
+ 'lookahead'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 2 }),
+ # allowed to advance to 'kur', but provides no benefits over 'kuq'
+ [qw(-kup kuq-lgup lguq-)],
+ 'minimal lookahead'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 3 }),
+ # shorten 'kuap' to 'ku' because lookbehind is 'kp...'
+ # 'lguq' matches 'lg', but may only backtrack to 'lgu'
+ [qw(-kt ku-lgt lgu-)],
+ 'lookbehind'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 4 }),
+ [qw(-kt ku-lf lg-)],
+ 'maximal lookahead'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 5 }),
+ # after forwarding 'kuap' to 'lc'
+ # disallow backtracking of 'lguq' to 'lc' to prevent qw[-k l-]
+ # so only lookahead (to 'lkq') remains
+ [qw(-k l-lj lk-)],
+ 'lookbehind forbidden'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 9 }),
+ # allow a single (10-9) entry (l-lf = lc) to remain
+ [qw(-k l-lf lg-)],
+ 'lookbehind penalty'
+ );
+ is_deeply(
+ $index->ranges(\@data, { context => 10 }),
+ # allow the last page to go back upto 'lc', replacing the 2nd page
+ [qw(-k l-)],
+ 'full overlap'
+ );