Added numeric range tests

compile.go

@@ -165,7 +165,10 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
 			var rangeStart int
 			var rangeEnd int
 			fmt.Sscanf(tmpStr, "%d-%d", &rangeStart, &rangeEnd)
-			regex := range2regex(rangeStart, rangeEnd)
+			regex, err := range2regex(rangeStart, rangeEnd)
+			if err != nil {
+				return nil, err
+			}
 			re_runes = append(re_runes, []rune(regex)...)
 		} else if c == '(' && i < len(re_runes_orig)-2 && re_runes_orig[i+1] == '?' && re_runes_orig[i+2] == ':' {
 			re_runes = append(re_runes, NONCAPLPAREN_CHAR)

range2regex.go

@@ -44,11 +44,11 @@ func intToSlc(val int) []int {
 	return toRet
 }
 
-func range2regex(start int, end int) string {
+func range2regex(start int, end int) (string, error) {
 	rangeStart := start
 	rangeEnd := end
 	if rangeStart > rangeEnd {
-		panic("Range start greater than range end.")
+		return "", fmt.Errorf("numeric range start greater than range end")
 	}
 
 	ranges := make([]numRange, 0)
@@ -99,17 +99,17 @@ func range2regex(start int, end int) string {
 	// Last range - tmp to rangeEnd
 	ranges = append(ranges, numRange{tmp, rangeEnd})
 
-	regex := "("
+	regex := string(NONCAPLPAREN_CHAR)
 	// Generate the regex
 	for i, rg := range ranges {
 		if i > 0 {
 			regex += "|"
 		}
-		regex += "("
+		regex += string(NONCAPLPAREN_CHAR)
 		startSlc := intToSlc(rg.start)
 		endSlc := intToSlc(rg.end)
 		if len(startSlc) != len(endSlc) {
-			panic("Ranges have unequal lengths.")
+			return "", fmt.Errorf("Error parsing numeric range")
 		}
 		for i := range startSlc {
 			if startSlc[i] == endSlc[i] {
@@ -121,6 +121,6 @@ func range2regex(start int, end int) string {
 		regex += ")"
 	}
 	regex += ")"
-	return regex
+	return regex, nil
 
 }

re_test.go

@@ -479,7 +479,35 @@ var reTests = []struct {
 	{`*?`, nil, `-`, nil},
 	{`a*?`, nil, `-`, nil}, // non-greedy operators are not supported
 
-	// Todo - add numeric range tests
+	// Numeric range tests - this is a feature that I added, and doesn't exist
+	// in any other mainstream regex engine
+	{`<0-255>`, nil, `0`, []Group{{0, 1}}},
+	{`<0-255>`, nil, `7`, []Group{{0, 1}}},
+	{`<0-255>`, nil, `46`, []Group{{0, 2}}},
+	{`<0-255>`, nil, `90`, []Group{{0, 2}}},
+	{`<0-255>`, nil, `107`, []Group{{0, 3}}},
+	{`<0-255>`, nil, `198`, []Group{{0, 3}}},
+	{`<0-255>`, nil, `254`, []Group{{0, 3}}},
+	{`<0-255>`, nil, `255`, []Group{{0, 3}}},
+	{`<0-255>`, nil, `256`, []Group{{0, 2}, {2, 3}}},
+	{`^<0-255>$`, nil, `256`, []Group{}},
+
+	{`^<0-299792458>$`, nil, `299000999`, []Group{{0, 9}}},
+	{`^<0-299792458>$`, nil, `299792531`, []Group{}},
+
+	{`^<3-0>$`, nil, `-`, nil},
+	{`^<0-0>$`, nil, `0`, []Group{{0, 1}}},
+	{`2<0-55>`, nil, `231`, []Group{{0, 3}}},
+	{`2<0-55>`, nil, `271`, []Group{{0, 2}}},
+	{`^2<0-55>$`, nil, `271`, []Group{}},
+
+	{`<389`, nil, `-`, nil},
+	{`<389>`, nil, `-`, nil},
+	{`<-389>`, nil, `-`, nil},
+	{`<389->`, nil, `-`, nil},
+	{`<389-400`, nil, `-`, nil},
+	{`<389-400>`, nil, `391`, []Group{{0, 3}}},
+	{`\b<1-10000>\b`, nil, `America declared independence in 1776.`, []Group{{33, 37}}},
 }
 
 var groupTests = []struct {
@@ -634,6 +662,8 @@ var groupTests = []struct {
 	{`^([ab]*)(?=(b)?)c`, nil, `abc`, []Match{[]Group{{0, 3}, {0, 2}}}},
 	{`^([ab]*)(?!(b))c`, nil, `abc`, []Match{[]Group{{0, 3}, {0, 2}}}},
 	{`^([ab]*)(?<!(a))c`, nil, `abc`, []Match{[]Group{{0, 3}, {0, 2}}}},
+
+	{`(<389-400>)`, nil, `391`, []Match{[]Group{{0, 3}, {0, 3}}}},
 }
 
 func TestFindAllMatches(t *testing.T) {