More simple regexp tests and test docs

2 files changed, 25 insertions, 1 deletions

diff --git a/t/op/re_tests b/t/op/re_tests
index c20fb89e80..77d97e2aeb 100644
--- a/t/op/re_tests
+++ b/t/op/re_tests
@@ -301,3 +301,6 @@ a(?:b|c|d)*(.)	ace	y	$1	e
 a(?:b|c|d)+?(.)	ace	y	$1	e
 a(?:b|(c|e){1,2}?|d)+?(.)	ace	y	$1$2	ce
 ^(.+)?B	AB	y	$1	A
+'([a-z]+)\s\1'i	Aa aa 	y	$&-$1	Aa aa-Aa
+'([a-z]+)\s\1'i	Ab ab 	y	$&-$1	Ab ab-Ab
+foo\w*\d{4}baz	foobar1234baz	y	$&	foobar1234baz
diff --git a/t/op/regexp.t b/t/op/regexp.t
index c6969240fc..ea470f879b 100755
--- a/t/op/regexp.t
+++ b/t/op/regexp.t
@@ -1,5 +1,26 @@
 #!./perl
 
+# The tests are in a separate file 't/op/re_tests'.
+# Each line in that file is a separate test.
+# There are five columns, separated by tabs.
+#
+# Column 1 contains the pattern, optionally enclosed in C<''>.
+# Modifiers can be put after the closing C<'>.
+#
+# Column 2 contains the string to be matched.
+#
+# Column 3 contains the expected result:
+# 	y	expect a match
+# 	n	expect no match
+# 	c	expect an error
+#
+# Columns 4 and 5 are used only of column 3 contains C<y>.
+#
+# Column 4 contains a string, usually C<$&>.
+#
+# Column 5 contains the expected result of double-quote
+# interpolating that string after the match.
+
 open(TESTS,'op/re_tests') || open(TESTS,'t/op/re_tests')
     || die "Can't open re_tests";
 
@@ -15,7 +36,7 @@ while (<TESTS>) {
     ($pat, $subject, $result, $repl, $expect) = split(/[\t\n]/,$_);
     $input = join(':',$pat,$subject,$result,$repl,$expect);
     $pat = "'$pat'" unless $pat =~ /^'/;
-    for $study ("", "study \$match") {
+    for $study ("", "study \$subject") {
 	eval "$study; \$match = (\$subject =~ m$pat); \$got = \"$repl\";";
 	if ($result eq 'c') {
 	    if ($@ eq '') { print "not ok $.\n"; next TEST }