diff --git a/re_test.go b/re_test.go
index b32b4ce..ef8c2d5 100644
--- a/re_test.go
+++ b/re_test.go
@@ -8,160 +8,166 @@ import (
 var reTests = []struct {
 	re     string
 	str    string
-	result []MatchIndex
+	result []Group // Stores all zero-groups in the match
 }{
-	{"a", "abc", []MatchIndex{{0, 1}}},
-	{"a", "bca", []MatchIndex{{2, 3}}},
-	{"l", "ggllgg", []MatchIndex{{2, 3}, {3, 4}}},
-	{"(b|c)", "abdceb", []MatchIndex{{1, 2}, {3, 4}, {5, 6}}},
-	{"a+", "brerereraaaaabbbbb", []MatchIndex{{8, 13}}},
-	{"ab+", "qweqweqweaqweqweabbbbbr", []MatchIndex{{16, 22}}},
-	{"(b|c|A)", "ooaoobocA", []MatchIndex{{5, 6}, {7, 8}, {8, 9}}},
-	{"ab*", "a", []MatchIndex{{0, 1}}},
-	{"ab*", "abb", []MatchIndex{{0, 3}}},
-	{"a*b", "aaab", []MatchIndex{{0, 4}}},
-	{"a*b", "qwqw", []MatchIndex{}},
-	{"(abc)*", "abcabcabc", []MatchIndex{{0, 9}, {9, 9}}},
-	{"((abc)|(def))*", "abcdef", []MatchIndex{{0, 6}, {6, 6}}},
-	{"(abc)*|(def)*", "abcdef", []MatchIndex{{0, 3}, {3, 6}, {6, 6}}},
-	{"b*a*a", "bba", []MatchIndex{{0, 3}}},
-	{"(ab)+", "abcabddd", []MatchIndex{{0, 2}, {3, 5}}},
-	{"a(b(c|d)*)*", "abccbd", []MatchIndex{{0, 6}}},
-	{"a(b|c)*d+", "abccdd", []MatchIndex{{0, 6}}},
-	{"a*", "", []MatchIndex{{0, 0}}},
-	{"a|b", "c", []MatchIndex{}},
-	{"(a|b)*c", "aabbc", []MatchIndex{{0, 5}}},
-	{"a(b|b)", "ab", []MatchIndex{{0, 2}}},
-	{"a*", "aaaaaaaa", []MatchIndex{{0, 8}, {8, 8}}},
+	{"a", "abc", []Group{{0, 1}}},
+	{"a", "bca", []Group{{2, 3}}},
+	{"l", "ggllgg", []Group{{2, 3}, {3, 4}}},
+	{"(b|c)", "abdceb", []Group{{1, 2}, {3, 4}, {5, 6}}},
+	{"a+", "brerereraaaaabbbbb", []Group{{8, 13}}},
+	{"ab+", "qweqweqweaqweqweabbbbbr", []Group{{16, 22}}},
+	{"(b|c|A)", "ooaoobocA", []Group{{5, 6}, {7, 8}, {8, 9}}},
+	{"ab*", "a", []Group{{0, 1}}},
+	{"ab*", "abb", []Group{{0, 3}}},
+	{"a*b", "aaab", []Group{{0, 4}}},
+	{"a*b", "qwqw", []Group{}},
+	{"(abc)*", "abcabcabc", []Group{{0, 9}, {9, 9}}},
+	{"((abc)|(def))*", "abcdef", []Group{{0, 6}, {6, 6}}},
+	{"(abc)*|(def)*", "abcdef", []Group{{0, 3}, {3, 6}, {6, 6}}},
+	{"b*a*a", "bba", []Group{{0, 3}}},
+	{"(ab)+", "abcabddd", []Group{{0, 2}, {3, 5}}},
+	{"a(b(c|d)*)*", "abccbd", []Group{{0, 6}}},
+	{"a(b|c)*d+", "abccdd", []Group{{0, 6}}},
+	{"a*", "", []Group{{0, 0}}},
+	{"a|b", "c", []Group{}},
+	{"(a|b)*c", "aabbc", []Group{{0, 5}}},
+	{"a(b|b)", "ab", []Group{{0, 2}}},
+	{"a*", "aaaaaaaa", []Group{{0, 8}, {8, 8}}},
 
-	{"ab?", "ab", []MatchIndex{{0, 2}}},
-	{"a?b", "ab", []MatchIndex{{0, 2}}},
-	{"a?", "", []MatchIndex{{0, 0}}},
-	{"a?b?c", "a", []MatchIndex{}},
-	{"a?b?c?", "ab", []MatchIndex{{0, 2}, {2, 2}}},
-	{"a?b?c?", "ac", []MatchIndex{{0, 2}, {2, 2}}},
-	{"a?b?c", "abc", []MatchIndex{{0, 3}}},
-	{"a?b?c", "acb", []MatchIndex{{0, 2}}},
+	{"ab?", "ab", []Group{{0, 2}}},
+	{"a?b", "ab", []Group{{0, 2}}},
+	{"a?", "", []Group{{0, 0}}},
+	{"a?b?c", "a", []Group{}},
+	{"a?b?c?", "ab", []Group{{0, 2}, {2, 2}}},
+	{"a?b?c?", "ac", []Group{{0, 2}, {2, 2}}},
+	{"a?b?c", "abc", []Group{{0, 3}}},
+	{"a?b?c", "acb", []Group{{0, 2}}},
 
-	{"[abc]", "defadefbdefce", []MatchIndex{{3, 4}, {7, 8}, {11, 12}}},
-	{"[ab]c", "ab", []MatchIndex{}},
-	{"g[ab]c", "gac", []MatchIndex{{0, 3}}},
-	{"g[ab]c", "gbc", []MatchIndex{{0, 3}}},
-	{"g[ab]c", "gc", []MatchIndex{}},
-	{"g[ab]c", "gfc", []MatchIndex{}},
-	{"[ab]*", "aabbbabaababab", []MatchIndex{{0, 14}, {14, 14}}},
-	{"[ab]+", "aabbbablaababab", []MatchIndex{{0, 7}, {8, 15}}},
-	{"[Ff]r[Uu]it", "fruit", []MatchIndex{{0, 5}}},
-	{"[Ff]r[Uu]it", "FrUit", []MatchIndex{{0, 5}}},
-	{"[Ff]r[Uu|]it", "Fr|it", []MatchIndex{{0, 5}}},
-	{"[Ff]r([Uu]|[pP])it", "Frpit", []MatchIndex{{0, 5}}},
-	{"[Ff]r[Uu]|[pP]it", "Frpit", []MatchIndex{{2, 5}}},
-	{"[a-zA-Z]+", "Hello, how is it going?", []MatchIndex{{0, 5}, {7, 10}, {11, 13}, {14, 16}, {17, 22}}},
+	{"[abc]", "defadefbdefce", []Group{{3, 4}, {7, 8}, {11, 12}}},
+	{"[ab]c", "ab", []Group{}},
+	{"g[ab]c", "gac", []Group{{0, 3}}},
+	{"g[ab]c", "gbc", []Group{{0, 3}}},
+	{"g[ab]c", "gc", []Group{}},
+	{"g[ab]c", "gfc", []Group{}},
+	{"[ab]*", "aabbbabaababab", []Group{{0, 14}, {14, 14}}},
+	{"[ab]+", "aabbbablaababab", []Group{{0, 7}, {8, 15}}},
+	{"[Ff]r[Uu]it", "fruit", []Group{{0, 5}}},
+	{"[Ff]r[Uu]it", "FrUit", []Group{{0, 5}}},
+	{"[Ff]r[Uu|]it", "Fr|it", []Group{{0, 5}}},
+	{"[Ff]r([Uu]|[pP])it", "Frpit", []Group{{0, 5}}},
+	{"[Ff]r[Uu]|[pP]it", "Frpit", []Group{{2, 5}}},
+	{"[a-zA-Z]+", "Hello, how is it going?", []Group{{0, 5}, {7, 10}, {11, 13}, {14, 16}, {17, 22}}},
 
-	{".+", "Hello, how is it going?", []MatchIndex{{0, 23}}},
-	{"a.", "a ", []MatchIndex{{0, 2}}},
-	{"a.b", "a/b", []MatchIndex{{0, 3}}},
-	{".", "a ", []MatchIndex{{0, 1}, {1, 2}}},
-	{"a.", "a ", []MatchIndex{{0, 2}}},
-	{".+b", "abc", []MatchIndex{{0, 2}}},
+	{".+", "Hello, how is it going?", []Group{{0, 23}}},
+	{"a.", "a ", []Group{{0, 2}}},
+	{"a.b", "a/b", []Group{{0, 3}}},
+	{".", "a ", []Group{{0, 1}, {1, 2}}},
+	{"a.", "a ", []Group{{0, 2}}},
+	{".+b", "abc", []Group{{0, 2}}},
 
-	{`\d`, "1a0a3s'''34343s", []MatchIndex{{0, 1}, {2, 3}, {4, 5}, {9, 10}, {10, 11}, {11, 12}, {12, 13}, {13, 14}}},
-	{`\\`, `a\b\c\qwe\`, []MatchIndex{{1, 2}, {3, 4}, {5, 6}, {9, 10}}},
-	{`\W`, `"Hello", he said. How are you doing?`, []MatchIndex{{0, 1}, {6, 7}, {7, 8}, {8, 9}, {11, 12}, {16, 17}, {17, 18}, {21, 22}, {25, 26}, {29, 30}, {35, 36}}},
-	{`\w`, ";';';';';'qwe12", []MatchIndex{{10, 11}, {11, 12}, {12, 13}, {13, 14}, {14, 15}}},
-	{`\s`, "a b c 	d", []MatchIndex{{1, 2}, {3, 4}, {5, 6}, {6, 7}}},
-	{`\<`, "<HTML><body>", []MatchIndex{{0, 1}, {6, 7}}},
-	{`\(.+\)`, "Not (paranthesized), (so) is (this) not", []MatchIndex{{4, 35}}},
+	{`\d`, "1a0a3s'''34343s", []Group{{0, 1}, {2, 3}, {4, 5}, {9, 10}, {10, 11}, {11, 12}, {12, 13}, {13, 14}}},
+	{`\\`, `a\b\c\qwe\`, []Group{{1, 2}, {3, 4}, {5, 6}, {9, 10}}},
+	{`\W`, `"Hello", he said. How are you doing?`, []Group{{0, 1}, {6, 7}, {7, 8}, {8, 9}, {11, 12}, {16, 17}, {17, 18}, {21, 22}, {25, 26}, {29, 30}, {35, 36}}},
+	{`\w`, ";';';';';'qwe12", []Group{{10, 11}, {11, 12}, {12, 13}, {13, 14}, {14, 15}}},
+	{`\s`, "a b c 	d", []Group{{1, 2}, {3, 4}, {5, 6}, {6, 7}}},
+	{`\<`, "<HTML><body>", []Group{{0, 1}, {6, 7}}},
+	{`\(.+\)`, "Not (paranthesized), (so) is (this) not", []Group{{4, 35}}},
 
-	{"[^abc]+", "qarbtopsaplpclkpasdmb prejip0r,p", []MatchIndex{{0, 1}, {2, 3}, {4, 8}, {9, 12}, {13, 16}, {17, 20}, {21, 32}}},
-	{"[^a]+", "qqqaq", []MatchIndex{{0, 3}, {4, 5}}},
-	{"[^0-9]+", "a1b2c3dd", []MatchIndex{{0, 1}, {2, 3}, {4, 5}, {6, 8}}},
-	{"[^abc]+", "ababababbababaccacacacaca", []MatchIndex{}},
-	{`\[`, "a[b[c[]]]", []MatchIndex{{1, 2}, {3, 4}, {5, 6}}},
-	{`\([^)]+\)`, "Not (paranthesized), (so) is (this) not", []MatchIndex{{4, 19}, {21, 25}, {29, 35}}},
+	{"[^abc]+", "qarbtopsaplpclkpasdmb prejip0r,p", []Group{{0, 1}, {2, 3}, {4, 8}, {9, 12}, {13, 16}, {17, 20}, {21, 32}}},
+	{"[^a]+", "qqqaq", []Group{{0, 3}, {4, 5}}},
+	{"[^0-9]+", "a1b2c3dd", []Group{{0, 1}, {2, 3}, {4, 5}, {6, 8}}},
+	{"[^abc]+", "ababababbababaccacacacaca", []Group{}},
+	{`\[`, "a[b[c[]]]", []Group{{1, 2}, {3, 4}, {5, 6}}},
+	{`\([^)]+\)`, "Not (paranthesized), (so) is (this) not", []Group{{4, 19}, {21, 25}, {29, 35}}},
 
-	{"^ab", "ab bab", []MatchIndex{{0, 2}}},
-	{"^aaaa^", "aaaaaaaa", []MatchIndex{}},
-	{"^([bB][Gg])", "bG", []MatchIndex{{0, 2}}},
-	{"b$", "ba", []MatchIndex{}},
-	{"(boy|girl)$", "girlf", []MatchIndex{}},
-	{`\bint\b`, "print int integer", []MatchIndex{{6, 9}}},
-	{`int\b`, "ints", []MatchIndex{}},
-	{`int(\b|a)`, "inta", []MatchIndex{{0, 4}}},
-	{`\b\d+\b`, "511 a3 43", []MatchIndex{{0, 3}, {7, 9}}},
-	{`\Bint\B`, "prints int integer print", []MatchIndex{{2, 5}}},
-	{`^`, "5^3^2", []MatchIndex{{0, 0}}},
-	{`\^`, "5^3^2", []MatchIndex{{1, 2}, {3, 4}}},
-	{`pool$`, "pool carpool", []MatchIndex{{8, 12}}},
-	{`^int$`, "print int integer", []MatchIndex{}},
-	{`^int$`, "int", []MatchIndex{{0, 3}}},
-	{`b*`, "aaaaaaaaaaqweqwe", []MatchIndex{{0, 0}, {1, 1}, {2, 2}, {3, 3}, {4, 4}, {5, 5}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}, {12, 12}, {13, 13}, {14, 14}, {15, 15}, {16, 16}}},
+	{"^ab", "ab bab", []Group{{0, 2}}},
+	{"^aaaa^", "aaaaaaaa", []Group{}},
+	{"^([bB][Gg])", "bG", []Group{{0, 2}}},
+	{"b$", "ba", []Group{}},
+	{"(boy|girl)$", "girlf", []Group{}},
+	{`\bint\b`, "print int integer", []Group{{6, 9}}},
+	{`int\b`, "ints", []Group{}},
+	{`int(\b|a)`, "inta", []Group{{0, 4}}},
+	{`\b\d+\b`, "511 a3 43", []Group{{0, 3}, {7, 9}}},
+	{`\Bint\B`, "prints int integer print", []Group{{2, 5}}},
+	{`^`, "5^3^2", []Group{{0, 0}}},
+	{`\^`, "5^3^2", []Group{{1, 2}, {3, 4}}},
+	{`pool$`, "pool carpool", []Group{{8, 12}}},
+	{`^int$`, "print int integer", []Group{}},
+	{`^int$`, "int", []Group{{0, 3}}},
+	{`b*`, "aaaaaaaaaaqweqwe", []Group{{0, 0}, {1, 1}, {2, 2}, {3, 3}, {4, 4}, {5, 5}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}, {12, 12}, {13, 13}, {14, 14}, {15, 15}, {16, 16}}},
 
-	{"a{4}", "aabaaa", []MatchIndex{}},
-	{"ab{5}", "abbbbbab", []MatchIndex{{0, 6}}},
-	{"(a|b){3,4}", "aba", []MatchIndex{{0, 3}}},
-	{"(a|b){3,4}", "ababaa", []MatchIndex{{0, 4}}},
-	{"(bc){5,}", "bcbcbcbcbcbcbcbc", []MatchIndex{{0, 16}}},
-	{`\d{3,4}`, "1209", []MatchIndex{{0, 4}}},
-	{`\d{3,4}`, "109", []MatchIndex{{0, 3}}},
-	{`\d{3,4}`, "5", []MatchIndex{}},
-	{`\d{3,4}`, "123135", []MatchIndex{{0, 4}}},
-	{`\d{3,4}`, "89a-0", []MatchIndex{}},
-	{`\d{3,4}`, "ababab555", []MatchIndex{{6, 9}}},
-	{`\bpaint\b`, "paints", []MatchIndex{}},
-	{`\b\w{5}\b`, "paint", []MatchIndex{{0, 5}}},
+	{"a{4}", "aabaaa", []Group{}},
+	{"ab{5}", "abbbbbab", []Group{{0, 6}}},
+	{"(a|b){3,4}", "aba", []Group{{0, 3}}},
+	{"(a|b){3,4}", "ababaa", []Group{{0, 4}}},
+	{"(bc){5,}", "bcbcbcbcbcbcbcbc", []Group{{0, 16}}},
+	{`\d{3,4}`, "1209", []Group{{0, 4}}},
+	{`\d{3,4}`, "109", []Group{{0, 3}}},
+	{`\d{3,4}`, "5", []Group{}},
+	{`\d{3,4}`, "123135", []Group{{0, 4}}},
+	{`\d{3,4}`, "89a-0", []Group{}},
+	{`\d{3,4}`, "ababab555", []Group{{6, 9}}},
+	{`\bpaint\b`, "paints", []Group{}},
+	{`\b\w{5}\b`, "paint", []Group{{0, 5}}},
 
 	// Unicode tests
-	{`.+`, "úïäö´«åæïëòöê»éãçâï«úïòíñ", []MatchIndex{{0, 25}}},
-	{`a.b`, "a²b", []MatchIndex{{0, 3}}},
-	{`[^a]+`, "úïäö´«åæïëòöê»éãçâï«úïòíñ", []MatchIndex{{0, 25}}},
+	{`.+`, "úïäö´«åæïëòöê»éãçâï«úïòíñ", []Group{{0, 25}}},
+	{`a.b`, "a²b", []Group{{0, 3}}},
+	{`[^a]+`, "úïäö´«åæïëòöê»éãçâï«úïòíñ", []Group{{0, 25}}},
 
 	// Fun experiment - AI-generated tests
-	{"(abc|def|ghi)", "abcdefg", []MatchIndex{{0, 3}, {3, 6}}},
-	{"a(b|c)d", "abcd", []MatchIndex{}},
-	{"a(b|c)*d", "abcbcd", []MatchIndex{{0, 6}}},
-	{"a(b|c)+d", "abcbcd", []MatchIndex{{0, 6}}},
-	{"a(b|c)?d", "abd", []MatchIndex{{0, 3}}},
-	{".+", "hello world", []MatchIndex{{0, 11}}},
-	{"a.b", "aXb", []MatchIndex{{0, 3}}},
-	{"a.*b", "aXb", []MatchIndex{{0, 3}}},
-	{"a.{2,3}b", "aXXb", []MatchIndex{{0, 4}}},
-	{"a.{2,}b", "aXXXb", []MatchIndex{{0, 5}}},
-	{"a.{0,3}b", "ab", []MatchIndex{{0, 2}}},
-	{"[abc]+", "abcabc", []MatchIndex{{0, 6}}},
-	{"[a-zA-Z]+", "HelloWorld", []MatchIndex{{0, 10}}},
-	{"[^abc]+", "defghi", []MatchIndex{{0, 6}}},
-	{"^hello", "hello world", []MatchIndex{{0, 5}}},
-	{"world$", "hello world", []MatchIndex{{6, 11}}},
-	{`\bhello\b`, "hello world", []MatchIndex{{0, 5}}},
-	{`\Bhello\B`, "hello world", []MatchIndex{}},
-	{"(hello|world)", "hello world", []MatchIndex{{0, 5}, {6, 11}}},
-	{"(hello|world)+", "hello world", []MatchIndex{{0, 5}, {6, 11}}},
-	{"(hello|world)*", "hello world", []MatchIndex{{0, 5}, {5, 5}, {6, 11}, {11, 11}}},
-	{"(hello|world)?", "hello world", []MatchIndex{{0, 5}, {5, 5}, {6, 11}, {11, 11}}},
-	{"ú.+ï", "úïäö´«åæïëòöê»éãçâï«úïòíñ", []MatchIndex{{0, 22}}},
-	{"(?=hello)", "hello world", []MatchIndex{{0, 0}}},
-	{"(?!hello)", "hello world", []MatchIndex{{1, 1}, {2, 2}, {3, 3}, {4, 4}, {5, 5}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}}},
-	{"(?<=hello)", "hello world", []MatchIndex{{5, 5}}},
-	{"(?<!hello)", "hello world", []MatchIndex{{0, 0}, {1, 1}, {2, 2}, {3, 3}, {4, 4}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}}},
-	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "40", []MatchIndex{{0, 2}}},
-	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "040", []MatchIndex{}},
-	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "400", []MatchIndex{{0, 3}}},
-	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "4000", []MatchIndex{}},
+	{"(abc|def|ghi)", "abcdefg", []Group{{0, 3}, {3, 6}}},
+	{"a(b|c)d", "abcd", []Group{}},
+	{"a(b|c)*d", "abcbcd", []Group{{0, 6}}},
+	{"a(b|c)+d", "abcbcd", []Group{{0, 6}}},
+	{"a(b|c)?d", "abd", []Group{{0, 3}}},
+	{".+", "hello world", []Group{{0, 11}}},
+	{"a.b", "aXb", []Group{{0, 3}}},
+	{"a.*b", "aXb", []Group{{0, 3}}},
+	{"a.{2,3}b", "aXXb", []Group{{0, 4}}},
+	{"a.{2,}b", "aXXXb", []Group{{0, 5}}},
+	{"a.{0,3}b", "ab", []Group{{0, 2}}},
+	{"[abc]+", "abcabc", []Group{{0, 6}}},
+	{"[a-zA-Z]+", "HelloWorld", []Group{{0, 10}}},
+	{"[^abc]+", "defghi", []Group{{0, 6}}},
+	{"^hello", "hello world", []Group{{0, 5}}},
+	{"world$", "hello world", []Group{{6, 11}}},
+	{`\bhello\b`, "hello world", []Group{{0, 5}}},
+	{`\Bhello\B`, "hello world", []Group{}},
+	{"(hello|world)", "hello world", []Group{{0, 5}, {6, 11}}},
+	{"(hello|world)+", "hello world", []Group{{0, 5}, {6, 11}}},
+	{"(hello|world)*", "hello world", []Group{{0, 5}, {5, 5}, {6, 11}, {11, 11}}},
+	{"(hello|world)?", "hello world", []Group{{0, 5}, {5, 5}, {6, 11}, {11, 11}}},
+	{"ú.+ï", "úïäö´«åæïëòöê»éãçâï«úïòíñ", []Group{{0, 22}}},
+	{"(?=hello)", "hello world", []Group{{0, 0}}},
+	{"(?!hello)", "hello world", []Group{{1, 1}, {2, 2}, {3, 3}, {4, 4}, {5, 5}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}}},
+	{"(?<=hello)", "hello world", []Group{{5, 5}}},
+	{"(?<!hello)", "hello world", []Group{{0, 0}, {1, 1}, {2, 2}, {3, 3}, {4, 4}, {6, 6}, {7, 7}, {8, 8}, {9, 9}, {10, 10}, {11, 11}}},
+	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "40", []Group{{0, 2}}},
+	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "040", []Group{}},
+	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "400", []Group{{0, 3}}},
+	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "4000", []Group{}},
 
 	// Todo - add lookaround tests
-	{"(?<=f)f+(?=f)", "fffff", []MatchIndex{{1, 4}}},
-	{"(?<=f)f+(?=f)", "fffffa", []MatchIndex{{1, 4}}},
+	// Todo - add numeric range tests
+	// Todo - add capturing group tests
+	{"(?<=f)f+(?=f)", "fffff", []Group{{1, 4}}},
+	{"(?<=f)f+(?=f)", "fffffa", []Group{{1, 4}}},
 }
 
 func TestFindAllMatches(t *testing.T) {
 	for _, test := range reTests {
 		t.Run(test.re+"	"+test.str, func(t *testing.T) {
 			re_postfix := shuntingYard(test.re)
-			startState := thompson(re_postfix)
-			matchIndices := findAllMatches(startState, []rune(test.str))
-			if !slices.Equal(test.result, matchIndices) {
-				t.Errorf("Wanted %v	Got %v\n", test.result, matchIndices)
+			startState, numGroups := thompson(re_postfix)
+			matchIndices := findAllMatches(startState, []rune(test.str), numGroups)
+			zeroGroups := make([]Group, len(matchIndices))
+			for i, m := range matchIndices {
+				zeroGroups[i] = m[0]
+			}
+			if !slices.Equal(test.result, zeroGroups) {
+				t.Errorf("Wanted %v	Got %v\n", test.result, zeroGroups)
 			}
 		})
 	}