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  • // Copyright 2009 The Go Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style
    // license that can be found in the LICENSE file.
    
    
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    package regexp
    
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    	"reflect"
    
    var good_re = []string{
    
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    	``,
    	`.`,
    	`^.$`,
    	`a`,
    	`a*`,
    	`a+`,
    	`a?`,
    	`a|b`,
    	`a*|b*`,
    	`(a*|b)(c*|d)`,
    	`[a-z]`,
    	`[a-abc-c\-\]\[]`,
    	`[a-z]+`,
    	`[abc]`,
    	`[^1234]`,
    
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    type stringError struct {
    
    	err string
    
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    }
    
    var bad_re = []stringError{
    
    	{`*`, "missing argument to repetition operator: `*`"},
    	{`+`, "missing argument to repetition operator: `+`"},
    	{`?`, "missing argument to repetition operator: `?`"},
    	{`(abc`, "missing closing ): `(abc`"},
    	{`abc)`, "unexpected ): `abc)`"},
    	{`x[a-z`, "missing closing ]: `[a-z`"},
    	{`[z-a]`, "invalid character class range: `z-a`"},
    	{`abc\`, "trailing backslash at end of expression"},
    	{`a**`, "invalid nested repetition operator: `**`"},
    	{`a*+`, "invalid nested repetition operator: `*+`"},
    	{`\x`, "invalid escape sequence: `\\x`"},
    
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    func compileTest(t *testing.T, expr string, error string) *Regexp {
    
    	re, err := Compile(expr)
    
    	if error == "" && err != nil {
    
    		t.Error("compiling `", expr, "`; unexpected error: ", err.Error())
    
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    	}
    
    	if error != "" && err == nil {
    		t.Error("compiling `", expr, "`; missing error")
    	} else if error != "" && !strings.Contains(err.Error(), error) {
    		t.Error("compiling `", expr, "`; wrong error: ", err.Error(), "; want ", error)
    	}
    
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    }
    
    
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    func TestGoodCompile(t *testing.T) {
    
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    	for i := 0; i < len(good_re); i++ {
    
    		compileTest(t, good_re[i], "")
    
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    	}
    
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    }
    
    
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    func TestBadCompile(t *testing.T) {
    
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    	for i := 0; i < len(bad_re); i++ {
    
    		compileTest(t, bad_re[i].re, bad_re[i].err)
    
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    	}
    
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    }
    
    
    func matchTest(t *testing.T, test *FindTest) {
    
    	re := compileTest(t, test.pat, "")
    
    	m := re.MatchString(test.text)
    	if m != (len(test.matches) > 0) {
    		t.Errorf("MatchString failure on %s: %t should be %t", test, m, len(test.matches) > 0)
    
    	m = re.Match([]byte(test.text))
    	if m != (len(test.matches) > 0) {
    		t.Errorf("Match failure on %s: %t should be %t", test, m, len(test.matches) > 0)
    
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    func TestMatch(t *testing.T) {
    
    	for _, test := range findTests {
    		matchTest(t, &test)
    
    func matchFunctionTest(t *testing.T, test *FindTest) {
    	m, err := MatchString(test.pat, test.text)
    
    	if m != (len(test.matches) > 0) {
    		t.Errorf("Match failure on %s: %t should be %t", test, m, len(test.matches) > 0)
    
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    func TestMatchFunction(t *testing.T) {
    
    	for _, test := range findTests {
    		matchFunctionTest(t, &test)
    
    
    type ReplaceTest struct {
    
    	pattern, replacement, input, output string
    
    var replaceTests = []ReplaceTest{
    
    	// Test empty input and/or replacement, with pattern that matches the empty string.
    
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    	{"", "", "", ""},
    	{"", "x", "", "x"},
    	{"", "", "abc", "abc"},
    	{"", "x", "abc", "xaxbxcx"},
    
    
    	// Test empty input and/or replacement, with pattern that does not match the empty string.
    
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    	{"b", "", "", ""},
    	{"b", "x", "", ""},
    	{"b", "", "abc", "ac"},
    	{"b", "x", "abc", "axc"},
    	{"y", "", "", ""},
    	{"y", "x", "", ""},
    	{"y", "", "abc", "abc"},
    	{"y", "x", "abc", "abc"},
    
    
    	// Multibyte characters -- verify that we don't try to match in the middle
    	// of a character.
    
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    	{"[a-c]*", "x", "\u65e5", "x\u65e5x"},
    	{"[^\u65e5]", "x", "abc\u65e5def", "xxx\u65e5xxx"},
    
    
    	// Start and end of a string.
    
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    	{"^[a-c]*", "x", "abcdabc", "xdabc"},
    	{"[a-c]*$", "x", "abcdabc", "abcdx"},
    	{"^[a-c]*$", "x", "abcdabc", "abcdabc"},
    	{"^[a-c]*", "x", "abc", "x"},
    	{"[a-c]*$", "x", "abc", "x"},
    	{"^[a-c]*$", "x", "abc", "x"},
    	{"^[a-c]*", "x", "dabce", "xdabce"},
    	{"[a-c]*$", "x", "dabce", "dabcex"},
    	{"^[a-c]*$", "x", "dabce", "dabce"},
    	{"^[a-c]*", "x", "", "x"},
    	{"[a-c]*$", "x", "", "x"},
    	{"^[a-c]*$", "x", "", "x"},
    
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    	{"^[a-c]+", "x", "abcdabc", "xdabc"},
    	{"[a-c]+$", "x", "abcdabc", "abcdx"},
    	{"^[a-c]+$", "x", "abcdabc", "abcdabc"},
    	{"^[a-c]+", "x", "abc", "x"},
    	{"[a-c]+$", "x", "abc", "x"},
    	{"^[a-c]+$", "x", "abc", "x"},
    	{"^[a-c]+", "x", "dabce", "dabce"},
    	{"[a-c]+$", "x", "dabce", "dabce"},
    	{"^[a-c]+$", "x", "dabce", "dabce"},
    	{"^[a-c]+", "x", "", ""},
    	{"[a-c]+$", "x", "", ""},
    	{"^[a-c]+$", "x", "", ""},
    
    
    	// Other cases.
    
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    	{"abc", "def", "abcdefg", "defdefg"},
    	{"bc", "BC", "abcbcdcdedef", "aBCBCdcdedef"},
    	{"abc", "", "abcdabc", "d"},
    	{"x", "xXx", "xxxXxxx", "xXxxXxxXxXxXxxXxxXx"},
    	{"abc", "d", "", ""},
    	{"abc", "d", "abc", "d"},
    	{".+", "x", "abc", "x"},
    	{"[a-c]*", "x", "def", "xdxexfx"},
    	{"[a-c]+", "x", "abcbcdcdedef", "xdxdedef"},
    	{"[a-c]*", "x", "abcbcdcdedef", "xdxdxexdxexfx"},
    
    
    	// Substitutions
    	{"a+", "($0)", "banana", "b(a)n(a)n(a)"},
    	{"a+", "(${0})", "banana", "b(a)n(a)n(a)"},
    	{"a+", "(${0})$0", "banana", "b(a)an(a)an(a)a"},
    	{"a+", "(${0})$0", "banana", "b(a)an(a)an(a)a"},
    	{"hello, (.+)", "goodbye, ${1}", "hello, world", "goodbye, world"},
    	{"hello, (.+)", "goodbye, $1x", "hello, world", "goodbye, "},
    	{"hello, (.+)", "goodbye, ${1}x", "hello, world", "goodbye, worldx"},
    	{"hello, (.+)", "<$0><$1><$2><$3>", "hello, world", "<hello, world><world><><>"},
    	{"hello, (?P<noun>.+)", "goodbye, $noun!", "hello, world", "goodbye, world!"},
    	{"hello, (?P<noun>.+)", "goodbye, ${noun}", "hello, world", "goodbye, world"},
    	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "hi", "hihihi"},
    	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "bye", "byebyebye"},
    	{"(?P<x>hi)|(?P<x>bye)", "$xyz", "hi", ""},
    	{"(?P<x>hi)|(?P<x>bye)", "${x}yz", "hi", "hiyz"},
    	{"(?P<x>hi)|(?P<x>bye)", "hello $$x", "hi", "hello $x"},
    	{"a+", "${oops", "aaa", "${oops"},
    	{"a+", "$$", "aaa", "$"},
    	{"a+", "$", "aaa", "$"},
    
    
    	// Substitution when subexpression isn't found
    	{"(x)?", "$1", "123", "123"},
    	{"abc", "$1", "123", "123"},
    
    }
    
    var replaceLiteralTests = []ReplaceTest{
    	// Substitutions
    	{"a+", "($0)", "banana", "b($0)n($0)n($0)"},
    	{"a+", "(${0})", "banana", "b(${0})n(${0})n(${0})"},
    	{"a+", "(${0})$0", "banana", "b(${0})$0n(${0})$0n(${0})$0"},
    	{"a+", "(${0})$0", "banana", "b(${0})$0n(${0})$0n(${0})$0"},
    	{"hello, (.+)", "goodbye, ${1}", "hello, world", "goodbye, ${1}"},
    	{"hello, (?P<noun>.+)", "goodbye, $noun!", "hello, world", "goodbye, $noun!"},
    	{"hello, (?P<noun>.+)", "goodbye, ${noun}", "hello, world", "goodbye, ${noun}"},
    	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "hi", "$x$x$x"},
    	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "bye", "$x$x$x"},
    	{"(?P<x>hi)|(?P<x>bye)", "$xyz", "hi", "$xyz"},
    	{"(?P<x>hi)|(?P<x>bye)", "${x}yz", "hi", "${x}yz"},
    	{"(?P<x>hi)|(?P<x>bye)", "hello $$x", "hi", "hello $$x"},
    	{"a+", "${oops", "aaa", "${oops"},
    	{"a+", "$$", "aaa", "$$"},
    	{"a+", "$", "aaa", "$"},
    
    type ReplaceFuncTest struct {
    	pattern       string
    	replacement   func(string) string
    	input, output string
    }
    
    var replaceFuncTests = []ReplaceFuncTest{
    
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    	{"[a-c]", func(s string) string { return "x" + s + "y" }, "defabcdef", "defxayxbyxcydef"},
    	{"[a-c]+", func(s string) string { return "x" + s + "y" }, "defabcdef", "defxabcydef"},
    	{"[a-c]*", func(s string) string { return "x" + s + "y" }, "defabcdef", "xydxyexyfxabcydxyexyfxy"},
    
    func TestReplaceAll(t *testing.T) {
    
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    	for _, tc := range replaceTests {
    
    		re, err := Compile(tc.pattern)
    
    		if err != nil {
    
    			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
    			continue
    
    		actual := re.ReplaceAllString(tc.input, tc.replacement)
    
    			t.Errorf("%q.ReplaceAllString(%q,%q) = %q; want %q",
    
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    
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    		actual = string(re.ReplaceAll([]byte(tc.input), []byte(tc.replacement)))
    
    		if actual != tc.output {
    
    			t.Errorf("%q.ReplaceAll(%q,%q) = %q; want %q",
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    		}
    	}
    }
    
    func TestReplaceAllLiteral(t *testing.T) {
    	// Run ReplaceAll tests that do not have $ expansions.
    	for _, tc := range replaceTests {
    		if strings.Contains(tc.replacement, "$") {
    			continue
    		}
    		re, err := Compile(tc.pattern)
    		if err != nil {
    			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
    			continue
    		}
    		actual := re.ReplaceAllLiteralString(tc.input, tc.replacement)
    		if actual != tc.output {
    			t.Errorf("%q.ReplaceAllLiteralString(%q,%q) = %q; want %q",
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    		}
    		// now try bytes
    		actual = string(re.ReplaceAllLiteral([]byte(tc.input), []byte(tc.replacement)))
    		if actual != tc.output {
    			t.Errorf("%q.ReplaceAllLiteral(%q,%q) = %q; want %q",
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    		}
    	}
    
    	// Run literal-specific tests.
    	for _, tc := range replaceLiteralTests {
    		re, err := Compile(tc.pattern)
    		if err != nil {
    			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
    			continue
    		}
    		actual := re.ReplaceAllLiteralString(tc.input, tc.replacement)
    		if actual != tc.output {
    			t.Errorf("%q.ReplaceAllLiteralString(%q,%q) = %q; want %q",
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    		}
    		// now try bytes
    		actual = string(re.ReplaceAllLiteral([]byte(tc.input), []byte(tc.replacement)))
    		if actual != tc.output {
    			t.Errorf("%q.ReplaceAllLiteral(%q,%q) = %q; want %q",
    
    				tc.pattern, tc.input, tc.replacement, actual, tc.output)
    
    func TestReplaceAllFunc(t *testing.T) {
    	for _, tc := range replaceFuncTests {
    		re, err := Compile(tc.pattern)
    		if err != nil {
    			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
    			continue
    		}
    		actual := re.ReplaceAllStringFunc(tc.input, tc.replacement)
    		if actual != tc.output {
    
    			t.Errorf("%q.ReplaceFunc(%q,fn) = %q; want %q",
    				tc.pattern, tc.input, actual, tc.output)
    
    		}
    		// now try bytes
    		actual = string(re.ReplaceAllFunc([]byte(tc.input), func(s []byte) []byte { return []byte(tc.replacement(string(s))) }))
    		if actual != tc.output {
    
    			t.Errorf("%q.ReplaceFunc(%q,fn) = %q; want %q",
    				tc.pattern, tc.input, actual, tc.output)
    
    type MetaTest struct {
    	pattern, output, literal string
    	isLiteral                bool
    
    var metaTests = []MetaTest{
    	{``, ``, ``, true},
    	{`foo`, `foo`, `foo`, true},
    	{`foo\.\$`, `foo\\\.\\\$`, `foo.$`, true}, // has meta but no operator
    	{`foo.\$`, `foo\.\\\$`, `foo`, false},     // has escaped operators and real operators
    
    	{`!@#$%^&*()_+-=[{]}\|,<.>/?~`, `!@#\$%\^&\*\(\)_\+-=\[\{\]\}\\\|,<\.>/\?~`, `!@#`, false},
    
    }
    
    func TestQuoteMeta(t *testing.T) {
    
    	for _, tc := range metaTests {
    
    		// Verify that QuoteMeta returns the expected string.
    
    		quoted := QuoteMeta(tc.pattern)
    
    		if quoted != tc.output {
    			t.Errorf("QuoteMeta(`%s`) = `%s`; want `%s`",
    
    				tc.pattern, quoted, tc.output)
    			continue
    
    		}
    
    		// Verify that the quoted string is in fact treated as expected
    		// by Compile -- i.e. that it matches the original, unquoted string.
    		if tc.pattern != "" {
    
    			re, err := Compile(quoted)
    
    			if err != nil {
    
    				t.Errorf("Unexpected error compiling QuoteMeta(`%s`): %v", tc.pattern, err)
    				continue
    
    			src := "abc" + tc.pattern + "def"
    			repl := "xyz"
    			replaced := re.ReplaceAllString(src, repl)
    			expected := "abcxyzdef"
    
    			if replaced != expected {
    				t.Errorf("QuoteMeta(`%s`).Replace(`%s`,`%s`) = `%s`; want `%s`",
    
    					tc.pattern, src, repl, replaced, expected)
    
    func TestLiteralPrefix(t *testing.T) {
    	for _, tc := range metaTests {
    		// Literal method needs to scan the pattern.
    		re := MustCompile(tc.pattern)
    		str, complete := re.LiteralPrefix()
    		if complete != tc.isLiteral {
    			t.Errorf("LiteralPrefix(`%s`) = %t; want %t", tc.pattern, complete, tc.isLiteral)
    		}
    		if str != tc.literal {
    			t.Errorf("LiteralPrefix(`%s`) = `%s`; want `%s`", tc.pattern, str, tc.literal)
    
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    type subexpCase struct {
    	input string
    	num   int
    	names []string
    
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    var subexpCases = []subexpCase{
    	{``, 0, nil},
    	{`.*`, 0, nil},
    	{`abba`, 0, nil},
    	{`ab(b)a`, 1, []string{"", ""}},
    	{`ab(.*)a`, 1, []string{"", ""}},
    	{`(.*)ab(.*)a`, 2, []string{"", "", ""}},
    	{`(.*)(ab)(.*)a`, 3, []string{"", "", "", ""}},
    	{`(.*)((a)b)(.*)a`, 4, []string{"", "", "", "", ""}},
    	{`(.*)(\(ab)(.*)a`, 3, []string{"", "", "", ""}},
    	{`(.*)(\(a\)b)(.*)a`, 3, []string{"", "", "", ""}},
    	{`(?P<foo>.*)(?P<bar>(a)b)(?P<foo>.*)a`, 4, []string{"", "foo", "bar", "", "foo"}},
    
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    func TestSubexp(t *testing.T) {
    	for _, c := range subexpCases {
    
    		n := re.NumSubexp()
    
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    		if n != c.num {
    			t.Errorf("%q: NumSubexp = %d, want %d", c.input, n, c.num)
    			continue
    		}
    		names := re.SubexpNames()
    		if len(names) != 1+n {
    			t.Errorf("%q: len(SubexpNames) = %d, want %d", c.input, len(names), n)
    			continue
    		}
    		if c.names != nil {
    			for i := 0; i < 1+n; i++ {
    				if names[i] != c.names[i] {
    					t.Errorf("%q: SubexpNames[%d] = %q, want %q", c.input, i, names[i], c.names[i])
    				}
    			}
    
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    var splitTests = []struct {
    	s   string
    	r   string
    	n   int
    	out []string
    }{
    	{"foo:and:bar", ":", -1, []string{"foo", "and", "bar"}},
    	{"foo:and:bar", ":", 1, []string{"foo:and:bar"}},
    	{"foo:and:bar", ":", 2, []string{"foo", "and:bar"}},
    	{"foo:and:bar", "foo", -1, []string{"", ":and:bar"}},
    	{"foo:and:bar", "bar", -1, []string{"foo:and:", ""}},
    	{"foo:and:bar", "baz", -1, []string{"foo:and:bar"}},
    	{"baabaab", "a", -1, []string{"b", "", "b", "", "b"}},
    	{"baabaab", "a*", -1, []string{"b", "b", "b"}},
    	{"baabaab", "ba*", -1, []string{"", "", "", ""}},
    	{"foobar", "f*b*", -1, []string{"", "o", "o", "a", "r"}},
    	{"foobar", "f+.*b+", -1, []string{"", "ar"}},
    	{"foobooboar", "o{2}", -1, []string{"f", "b", "boar"}},
    	{"a,b,c,d,e,f", ",", 3, []string{"a", "b", "c,d,e,f"}},
    	{"a,b,c,d,e,f", ",", 0, nil},
    	{",", ",", -1, []string{"", ""}},
    	{",,,", ",", -1, []string{"", "", "", ""}},
    	{"", ",", -1, []string{""}},
    	{"", ".*", -1, []string{""}},
    	{"", ".+", -1, []string{""}},
    	{"", "", -1, []string{}},
    	{"foobar", "", -1, []string{"f", "o", "o", "b", "a", "r"}},
    	{"abaabaccadaaae", "a*", 5, []string{"", "b", "b", "c", "cadaaae"}},
    	{":x:y:z:", ":", -1, []string{"", "x", "y", "z", ""}},
    }
    
    func TestSplit(t *testing.T) {
    	for i, test := range splitTests {
    		re, err := Compile(test.r)
    		if err != nil {
    			t.Errorf("#%d: %q: compile error: %s", i, test.r, err.Error())
    			continue
    		}
    
    		split := re.Split(test.s, test.n)
    		if !reflect.DeepEqual(split, test.out) {
    			t.Errorf("#%d: %q: got %q; want %q", i, test.r, split, test.out)
    		}
    
    		if QuoteMeta(test.r) == test.r {
    			strsplit := strings.SplitN(test.s, test.r, test.n)
    			if !reflect.DeepEqual(split, strsplit) {
    				t.Errorf("#%d: Split(%q, %q, %d): regexp vs strings mismatch\nregexp=%q\nstrings=%q", i, test.s, test.r, test.n, split, strsplit)
    			}
    		}
    	}
    }
    
    
    func BenchmarkLiteral(b *testing.B) {
    
    	x := strings.Repeat("x", 50) + "y"
    
    	re := MustCompile("y")
    
    	for i := 0; i < b.N; i++ {
    		if !re.MatchString(x) {
    
    			b.Fatalf("no match!")
    
    		}
    	}
    }
    
    func BenchmarkNotLiteral(b *testing.B) {
    
    	x := strings.Repeat("x", 50) + "y"
    
    	re := MustCompile(".y")
    
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		if !re.MatchString(x) {
    
    			b.Fatalf("no match!")
    
    		}
    	}
    }
    
    func BenchmarkMatchClass(b *testing.B) {
    	b.StopTimer()
    	x := strings.Repeat("xxxx", 20) + "w"
    	re := MustCompile("[abcdw]")
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		if !re.MatchString(x) {
    
    			b.Fatalf("no match!")
    
    		}
    	}
    }
    
    func BenchmarkMatchClass_InRange(b *testing.B) {
    	b.StopTimer()
    
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    	// 'b' is between 'a' and 'c', so the charclass
    
    	// range checking is no help here.
    	x := strings.Repeat("bbbb", 20) + "c"
    	re := MustCompile("[ac]")
    
    	for i := 0; i < b.N; i++ {
    		if !re.MatchString(x) {
    
    			b.Fatalf("no match!")
    
    
    func BenchmarkReplaceAll(b *testing.B) {
    	x := "abcdefghijklmnopqrstuvwxyz"
    	b.StopTimer()
    
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		re.ReplaceAllString(x, "")
    	}
    }
    
    
    func BenchmarkAnchoredLiteralShortNonMatch(b *testing.B) {
    	b.StopTimer()
    	x := []byte("abcdefghijklmnopqrstuvwxyz")
    	re := MustCompile("^zbc(d|e)")
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		re.Match(x)
    	}
    }
    
    func BenchmarkAnchoredLiteralLongNonMatch(b *testing.B) {
    	b.StopTimer()
    	x := []byte("abcdefghijklmnopqrstuvwxyz")
    	for i := 0; i < 15; i++ {
    		x = append(x, x...)
    	}
    	re := MustCompile("^zbc(d|e)")
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		re.Match(x)
    	}
    }
    
    func BenchmarkAnchoredShortMatch(b *testing.B) {
    	b.StopTimer()
    	x := []byte("abcdefghijklmnopqrstuvwxyz")
    	re := MustCompile("^.bc(d|e)")
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		re.Match(x)
    	}
    }
    
    func BenchmarkAnchoredLongMatch(b *testing.B) {
    	b.StopTimer()
    	x := []byte("abcdefghijklmnopqrstuvwxyz")
    	for i := 0; i < 15; i++ {
    		x = append(x, x...)
    	}
    	re := MustCompile("^.bc(d|e)")
    	b.StartTimer()
    	for i := 0; i < b.N; i++ {
    		re.Match(x)
    	}
    }