Added more tests; added backreference comment

re_test.go

@@ -287,6 +287,11 @@ var reTests = []struct {
 	{`multiple words`, nil, `multiple words, yeah`, []Group{{0, 14}}},
 	{`[k]`, nil, `ab`, []Group{}},
 	{`a[-]?c`, nil, `ac`, []Group{{0, 2}}},
+	{`^(.+)?B`, nil, `AB`, []Group{{0, 2}}},
+
+	// At this point, the python test suite has a bunch
+	// of backreference tests. Since my engine doesn't
+	// implement backreferences, I've skipped those tests.
 
 	// Todo - add numeric range tests
 }
@@ -348,6 +353,22 @@ var groupTests = []struct {
 	{`(((((((((a)))))))))`, nil, `a`, []Match{[]Group{{0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}, {0, 1}}}},
 	{`(.*)c(.*)`, nil, `abcde`, []Match{[]Group{{0, 5}, {0, 2}, {3, 5}}}},
 	{`\((.*), (.*)\)`, nil, `(a, b)`, []Match{[]Group{{0, 6}, {1, 2}, {4, 5}}}},
+
+	// At this point, the python test suite has a bunch
+	// of backreference tests. Since my engine doesn't
+	// implement backreferences, I've skipped those tests.
+
+	{`(a)(b)c|ab`, nil, `ab`, []Match{[]Group{{0, 2}}}},
+	{`(a)+x`, nil, `aaax`, []Match{[]Group{{0, 4}, {2, 3}}}},
+	{`([ac])+x`, nil, `aacx`, []Match{[]Group{{0, 4}, {2, 3}}}},
+	{`([^/]*/)*sub1/`, nil, `d:msgs/tdir/sub1/trial/away.cpp`, []Match{[]Group{{0, 17}, {7, 12}}}},
+	{`([^.]*)\.([^:]*):[T ]+(.*)`, nil, `track1.title:TBlah blah blah`, []Match{[]Group{{0, 28}, {0, 6}, {7, 12}, {14, 28}}}},
+	{`([^N]*N)+`, nil, `abNNxyzN`, []Match{[]Group{{0, 8}, {4, 8}}}},
+	{`([^N]*N)+`, nil, `abNNxyz`, []Match{[]Group{{0, 4}, {3, 4}}}},
+	{`([abc]*)x`, nil, `abcx`, []Match{[]Group{{0, 4}, {0, 3}}}},
+	{`([abc]*)x`, nil, `abc`, []Match{}},
+	{`([xyz]*)x`, nil, `abcx`, []Match{[]Group{{3, 4}, {3, 3}}}},
+	{`(a)+b|aac`, nil, `aac`, []Match{[]Group{{0, 3}}}},
 }
 
 func TestFindAllMatches(t *testing.T) {