X-Git-Url: http://git.shiar.nl/perl/list-index.git/blobdiff_plain/e5fa8cd7b5cc84943c5f7c32c4f34974613a235b..fd5749ab518cdf3c68e94fbad168aa2a7725d592:/t/10-ranges.t

diff --git a/t/10-ranges.t b/t/10-ranges.t
index d96ebb5..cf3b0a4 100644
--- a/t/10-ranges.t
+++ b/t/10-ranges.t
@@ -2,7 +2,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 7;
+use Test::More tests => 8;
 use Test::NoWarnings;
 use Data::Dump 'pp';
 
@@ -33,33 +33,40 @@ subtest 'uniform alphanumeric' => sub {
 };
 
 subtest 'context' => sub {
-	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}));
-};
-
-subtest 'distribution' => sub {
-	plan tests => 3;
+	plan tests => 9;
 	my $index = List::Index->new([qw(
 		kkeg kl km kmlu knsy    koxb kpeo kuaa kuab kuac
-		kuap kuaq kuq kux kzb   lc lg lgu lgua lguc
+		kuapa kuq kur kux kzb   lc lg lgu lgua lguc
 		lguq lgur lgus lgx lka  lkq lks lln llq llx
 	)]) or return;
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>0, length=>5 }),
+		# ranges should match offsets exactly
+		[qw(-kuap. kuapa-lgup lguq-)],
+		'no context'
+	);
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>0 }),
+		# default length limits to 4 chars
+		[qw(-kuao kuap-lgup lguq-)],
+		'default length'
+	);
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>1 }),
+		# lookbehinds aren't shorter (kuac<kuap, lguc<lguq)
+		# 'kuap' can advance to 'kuq'
+		[qw(-kup kuq-lgup lguq-)],
+		'lookahead'
+	);
+TODO: {
+	local $TODO = 'backtrack';
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>2 }),
+		# allowed to advance to 'kur', but provides no benefits over 'kuq'
+		[qw(-kup kuq-lgup lguq-)],
+		'minimal lookahead'
+	);
+}
 	is_deeply(
 		$index->ranges({ pagesize=>10, context=>3 }),
 		# shorten 'kuap' to 'ku' because lookbehind is 'kp...'
@@ -78,7 +85,66 @@ subtest 'distribution' => sub {
 		# disallow backtracking of 'lguq' to 'lc' to prevent qw[-k l-]
 		# so only lookahead (to 'lkq') remains
 		[qw(-k l-lj lk-)],
-		'lookbehind after full lookahead'
+		'lookbehind forbidden'
+	);
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>9 }),
+		# allow a single (10-9) entry (l-lf = lc) to remain
+		[qw(-k l-lf lg-)],
+		'lookbehind penalty'
+	);
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>10 }),
+		# allow the last page to go back upto 'lc', replacing the 2nd page
+		[qw(-k l-)],
+		'full overlap'
 	);
+};
+
+subtest 'distribution' => sub {
+	plan tests => 2;
+	my $index = List::Index->new([qw(
+		gnihka gniub go gsearnrqns gtdvcxyt gw gwoufolwcvmtueyg gysgphci h habkdgifjfxoh
+		hbbvjf hbqleexnqts hccg hd hdoeqwdmgqwaoya hfbegicieuxz hfm hj hkoysmws hmylu
+		hnvtvpievbdlkrmb hs hvdvcqn hvn hyrybeur iaiaab ib ibavqyar idfniqvxpohbk idh
+	)]) or return;
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>6 }),
+		[qw(-g h i-)],
+		'large context'
+	);
+{ local $TODO = '?';
+	is_deeply(
+		$index->ranges({ pagesize=>10, context=>5 }),
+		# after 2nd page is enlarged by lookbehind to 'h', limit subsequent lookahead
+		# to prevent the page from getting too large (17 entries if forwarded to 'i')
+		[qw(-g h-hm hn-)],
+		'lookahead penalty'
+	);
+	# page #14 [gn-g] (8): gnihka gniub go gsearnrqns gtdvcxyt gwawkvmueovdjtfj gwoufolwcvmtueyg gysgphci
+	# page #15 [h] (17): h habkdgifjfxoh hbbvjf hbqleexnqts hccgszftbaymfu hdaqzkow hdoeqwdmgqwaoya hfbegicieu hfmlpzzioqjbthz hj hkoysmws hmylu hnvtvpievbdlkrmb hsodfpkatk hvdvcqn hvn hyrybeurqtevjfmi
+	# page #16 [i-ie] (5): i iaab ibiavqyar idfniqvxpohbk idh
 }
+};
+
+subtest 'context' => sub {
+	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}));
+};