github.com/shijuvar/go@v0.0.0-20141209052335-e8f13700b70c/src/regexp/all_test.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package regexp
     6  
     7  import (
     8  	"reflect"
     9  	"regexp/syntax"
    10  	"strings"
    11  	"testing"
    12  )
    13  
    14  var good_re = []string{
    15  	``,
    16  	`.`,
    17  	`^.$`,
    18  	`a`,
    19  	`a*`,
    20  	`a+`,
    21  	`a?`,
    22  	`a|b`,
    23  	`a*|b*`,
    24  	`(a*|b)(c*|d)`,
    25  	`[a-z]`,
    26  	`[a-abc-c\-\]\[]`,
    27  	`[a-z]+`,
    28  	`[abc]`,
    29  	`[^1234]`,
    30  	`[^\n]`,
    31  	`\!\\`,
    32  }
    33  
    34  type stringError struct {
    35  	re  string
    36  	err string
    37  }
    38  
    39  var bad_re = []stringError{
    40  	{`*`, "missing argument to repetition operator: `*`"},
    41  	{`+`, "missing argument to repetition operator: `+`"},
    42  	{`?`, "missing argument to repetition operator: `?`"},
    43  	{`(abc`, "missing closing ): `(abc`"},
    44  	{`abc)`, "unexpected ): `abc)`"},
    45  	{`x[a-z`, "missing closing ]: `[a-z`"},
    46  	{`[z-a]`, "invalid character class range: `z-a`"},
    47  	{`abc\`, "trailing backslash at end of expression"},
    48  	{`a**`, "invalid nested repetition operator: `**`"},
    49  	{`a*+`, "invalid nested repetition operator: `*+`"},
    50  	{`\x`, "invalid escape sequence: `\\x`"},
    51  }
    52  
    53  func compileTest(t *testing.T, expr string, error string) *Regexp {
    54  	re, err := Compile(expr)
    55  	if error == "" && err != nil {
    56  		t.Error("compiling `", expr, "`; unexpected error: ", err.Error())
    57  	}
    58  	if error != "" && err == nil {
    59  		t.Error("compiling `", expr, "`; missing error")
    60  	} else if error != "" && !strings.Contains(err.Error(), error) {
    61  		t.Error("compiling `", expr, "`; wrong error: ", err.Error(), "; want ", error)
    62  	}
    63  	return re
    64  }
    65  
    66  func TestGoodCompile(t *testing.T) {
    67  	for i := 0; i < len(good_re); i++ {
    68  		compileTest(t, good_re[i], "")
    69  	}
    70  }
    71  
    72  func TestBadCompile(t *testing.T) {
    73  	for i := 0; i < len(bad_re); i++ {
    74  		compileTest(t, bad_re[i].re, bad_re[i].err)
    75  	}
    76  }
    77  
    78  func matchTest(t *testing.T, test *FindTest) {
    79  	re := compileTest(t, test.pat, "")
    80  	if re == nil {
    81  		return
    82  	}
    83  	m := re.MatchString(test.text)
    84  	if m != (len(test.matches) > 0) {
    85  		t.Errorf("MatchString failure on %s: %t should be %t", test, m, len(test.matches) > 0)
    86  	}
    87  	// now try bytes
    88  	m = re.Match([]byte(test.text))
    89  	if m != (len(test.matches) > 0) {
    90  		t.Errorf("Match failure on %s: %t should be %t", test, m, len(test.matches) > 0)
    91  	}
    92  }
    93  
    94  func TestMatch(t *testing.T) {
    95  	for _, test := range findTests {
    96  		matchTest(t, &test)
    97  	}
    98  }
    99  
   100  func matchFunctionTest(t *testing.T, test *FindTest) {
   101  	m, err := MatchString(test.pat, test.text)
   102  	if err == nil {
   103  		return
   104  	}
   105  	if m != (len(test.matches) > 0) {
   106  		t.Errorf("Match failure on %s: %t should be %t", test, m, len(test.matches) > 0)
   107  	}
   108  }
   109  
   110  func TestMatchFunction(t *testing.T) {
   111  	for _, test := range findTests {
   112  		matchFunctionTest(t, &test)
   113  	}
   114  }
   115  
   116  type ReplaceTest struct {
   117  	pattern, replacement, input, output string
   118  }
   119  
   120  var replaceTests = []ReplaceTest{
   121  	// Test empty input and/or replacement, with pattern that matches the empty string.
   122  	{"", "", "", ""},
   123  	{"", "x", "", "x"},
   124  	{"", "", "abc", "abc"},
   125  	{"", "x", "abc", "xaxbxcx"},
   126  
   127  	// Test empty input and/or replacement, with pattern that does not match the empty string.
   128  	{"b", "", "", ""},
   129  	{"b", "x", "", ""},
   130  	{"b", "", "abc", "ac"},
   131  	{"b", "x", "abc", "axc"},
   132  	{"y", "", "", ""},
   133  	{"y", "x", "", ""},
   134  	{"y", "", "abc", "abc"},
   135  	{"y", "x", "abc", "abc"},
   136  
   137  	// Multibyte characters -- verify that we don't try to match in the middle
   138  	// of a character.
   139  	{"[a-c]*", "x", "\u65e5", "x\u65e5x"},
   140  	{"[^\u65e5]", "x", "abc\u65e5def", "xxx\u65e5xxx"},
   141  
   142  	// Start and end of a string.
   143  	{"^[a-c]*", "x", "abcdabc", "xdabc"},
   144  	{"[a-c]*$", "x", "abcdabc", "abcdx"},
   145  	{"^[a-c]*$", "x", "abcdabc", "abcdabc"},
   146  	{"^[a-c]*", "x", "abc", "x"},
   147  	{"[a-c]*$", "x", "abc", "x"},
   148  	{"^[a-c]*$", "x", "abc", "x"},
   149  	{"^[a-c]*", "x", "dabce", "xdabce"},
   150  	{"[a-c]*$", "x", "dabce", "dabcex"},
   151  	{"^[a-c]*$", "x", "dabce", "dabce"},
   152  	{"^[a-c]*", "x", "", "x"},
   153  	{"[a-c]*$", "x", "", "x"},
   154  	{"^[a-c]*$", "x", "", "x"},
   155  
   156  	{"^[a-c]+", "x", "abcdabc", "xdabc"},
   157  	{"[a-c]+$", "x", "abcdabc", "abcdx"},
   158  	{"^[a-c]+$", "x", "abcdabc", "abcdabc"},
   159  	{"^[a-c]+", "x", "abc", "x"},
   160  	{"[a-c]+$", "x", "abc", "x"},
   161  	{"^[a-c]+$", "x", "abc", "x"},
   162  	{"^[a-c]+", "x", "dabce", "dabce"},
   163  	{"[a-c]+$", "x", "dabce", "dabce"},
   164  	{"^[a-c]+$", "x", "dabce", "dabce"},
   165  	{"^[a-c]+", "x", "", ""},
   166  	{"[a-c]+$", "x", "", ""},
   167  	{"^[a-c]+$", "x", "", ""},
   168  
   169  	// Other cases.
   170  	{"abc", "def", "abcdefg", "defdefg"},
   171  	{"bc", "BC", "abcbcdcdedef", "aBCBCdcdedef"},
   172  	{"abc", "", "abcdabc", "d"},
   173  	{"x", "xXx", "xxxXxxx", "xXxxXxxXxXxXxxXxxXx"},
   174  	{"abc", "d", "", ""},
   175  	{"abc", "d", "abc", "d"},
   176  	{".+", "x", "abc", "x"},
   177  	{"[a-c]*", "x", "def", "xdxexfx"},
   178  	{"[a-c]+", "x", "abcbcdcdedef", "xdxdedef"},
   179  	{"[a-c]*", "x", "abcbcdcdedef", "xdxdxexdxexfx"},
   180  
   181  	// Substitutions
   182  	{"a+", "($0)", "banana", "b(a)n(a)n(a)"},
   183  	{"a+", "(${0})", "banana", "b(a)n(a)n(a)"},
   184  	{"a+", "(${0})$0", "banana", "b(a)an(a)an(a)a"},
   185  	{"a+", "(${0})$0", "banana", "b(a)an(a)an(a)a"},
   186  	{"hello, (.+)", "goodbye, ${1}", "hello, world", "goodbye, world"},
   187  	{"hello, (.+)", "goodbye, $1x", "hello, world", "goodbye, "},
   188  	{"hello, (.+)", "goodbye, ${1}x", "hello, world", "goodbye, worldx"},
   189  	{"hello, (.+)", "<$0><$1><$2><$3>", "hello, world", "<hello, world><world><><>"},
   190  	{"hello, (?P<noun>.+)", "goodbye, $noun!", "hello, world", "goodbye, world!"},
   191  	{"hello, (?P<noun>.+)", "goodbye, ${noun}", "hello, world", "goodbye, world"},
   192  	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "hi", "hihihi"},
   193  	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "bye", "byebyebye"},
   194  	{"(?P<x>hi)|(?P<x>bye)", "$xyz", "hi", ""},
   195  	{"(?P<x>hi)|(?P<x>bye)", "${x}yz", "hi", "hiyz"},
   196  	{"(?P<x>hi)|(?P<x>bye)", "hello $$x", "hi", "hello $x"},
   197  	{"a+", "${oops", "aaa", "${oops"},
   198  	{"a+", "$$", "aaa", "$"},
   199  	{"a+", "$", "aaa", "$"},
   200  
   201  	// Substitution when subexpression isn't found
   202  	{"(x)?", "$1", "123", "123"},
   203  	{"abc", "$1", "123", "123"},
   204  }
   205  
   206  var replaceLiteralTests = []ReplaceTest{
   207  	// Substitutions
   208  	{"a+", "($0)", "banana", "b($0)n($0)n($0)"},
   209  	{"a+", "(${0})", "banana", "b(${0})n(${0})n(${0})"},
   210  	{"a+", "(${0})$0", "banana", "b(${0})$0n(${0})$0n(${0})$0"},
   211  	{"a+", "(${0})$0", "banana", "b(${0})$0n(${0})$0n(${0})$0"},
   212  	{"hello, (.+)", "goodbye, ${1}", "hello, world", "goodbye, ${1}"},
   213  	{"hello, (?P<noun>.+)", "goodbye, $noun!", "hello, world", "goodbye, $noun!"},
   214  	{"hello, (?P<noun>.+)", "goodbye, ${noun}", "hello, world", "goodbye, ${noun}"},
   215  	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "hi", "$x$x$x"},
   216  	{"(?P<x>hi)|(?P<x>bye)", "$x$x$x", "bye", "$x$x$x"},
   217  	{"(?P<x>hi)|(?P<x>bye)", "$xyz", "hi", "$xyz"},
   218  	{"(?P<x>hi)|(?P<x>bye)", "${x}yz", "hi", "${x}yz"},
   219  	{"(?P<x>hi)|(?P<x>bye)", "hello $$x", "hi", "hello $$x"},
   220  	{"a+", "${oops", "aaa", "${oops"},
   221  	{"a+", "$$", "aaa", "$$"},
   222  	{"a+", "$", "aaa", "$"},
   223  }
   224  
   225  type ReplaceFuncTest struct {
   226  	pattern       string
   227  	replacement   func(string) string
   228  	input, output string
   229  }
   230  
   231  var replaceFuncTests = []ReplaceFuncTest{
   232  	{"[a-c]", func(s string) string { return "x" + s + "y" }, "defabcdef", "defxayxbyxcydef"},
   233  	{"[a-c]+", func(s string) string { return "x" + s + "y" }, "defabcdef", "defxabcydef"},
   234  	{"[a-c]*", func(s string) string { return "x" + s + "y" }, "defabcdef", "xydxyexyfxabcydxyexyfxy"},
   235  }
   236  
   237  func TestReplaceAll(t *testing.T) {
   238  	for _, tc := range replaceTests {
   239  		re, err := Compile(tc.pattern)
   240  		if err != nil {
   241  			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
   242  			continue
   243  		}
   244  		actual := re.ReplaceAllString(tc.input, tc.replacement)
   245  		if actual != tc.output {
   246  			t.Errorf("%q.ReplaceAllString(%q,%q) = %q; want %q",
   247  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   248  		}
   249  		// now try bytes
   250  		actual = string(re.ReplaceAll([]byte(tc.input), []byte(tc.replacement)))
   251  		if actual != tc.output {
   252  			t.Errorf("%q.ReplaceAll(%q,%q) = %q; want %q",
   253  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   254  		}
   255  	}
   256  }
   257  
   258  func TestReplaceAllLiteral(t *testing.T) {
   259  	// Run ReplaceAll tests that do not have $ expansions.
   260  	for _, tc := range replaceTests {
   261  		if strings.Contains(tc.replacement, "$") {
   262  			continue
   263  		}
   264  		re, err := Compile(tc.pattern)
   265  		if err != nil {
   266  			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
   267  			continue
   268  		}
   269  		actual := re.ReplaceAllLiteralString(tc.input, tc.replacement)
   270  		if actual != tc.output {
   271  			t.Errorf("%q.ReplaceAllLiteralString(%q,%q) = %q; want %q",
   272  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   273  		}
   274  		// now try bytes
   275  		actual = string(re.ReplaceAllLiteral([]byte(tc.input), []byte(tc.replacement)))
   276  		if actual != tc.output {
   277  			t.Errorf("%q.ReplaceAllLiteral(%q,%q) = %q; want %q",
   278  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   279  		}
   280  	}
   281  
   282  	// Run literal-specific tests.
   283  	for _, tc := range replaceLiteralTests {
   284  		re, err := Compile(tc.pattern)
   285  		if err != nil {
   286  			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
   287  			continue
   288  		}
   289  		actual := re.ReplaceAllLiteralString(tc.input, tc.replacement)
   290  		if actual != tc.output {
   291  			t.Errorf("%q.ReplaceAllLiteralString(%q,%q) = %q; want %q",
   292  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   293  		}
   294  		// now try bytes
   295  		actual = string(re.ReplaceAllLiteral([]byte(tc.input), []byte(tc.replacement)))
   296  		if actual != tc.output {
   297  			t.Errorf("%q.ReplaceAllLiteral(%q,%q) = %q; want %q",
   298  				tc.pattern, tc.input, tc.replacement, actual, tc.output)
   299  		}
   300  	}
   301  }
   302  
   303  func TestReplaceAllFunc(t *testing.T) {
   304  	for _, tc := range replaceFuncTests {
   305  		re, err := Compile(tc.pattern)
   306  		if err != nil {
   307  			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err)
   308  			continue
   309  		}
   310  		actual := re.ReplaceAllStringFunc(tc.input, tc.replacement)
   311  		if actual != tc.output {
   312  			t.Errorf("%q.ReplaceFunc(%q,fn) = %q; want %q",
   313  				tc.pattern, tc.input, actual, tc.output)
   314  		}
   315  		// now try bytes
   316  		actual = string(re.ReplaceAllFunc([]byte(tc.input), func(s []byte) []byte { return []byte(tc.replacement(string(s))) }))
   317  		if actual != tc.output {
   318  			t.Errorf("%q.ReplaceFunc(%q,fn) = %q; want %q",
   319  				tc.pattern, tc.input, actual, tc.output)
   320  		}
   321  	}
   322  }
   323  
   324  type MetaTest struct {
   325  	pattern, output, literal string
   326  	isLiteral                bool
   327  }
   328  
   329  var metaTests = []MetaTest{
   330  	{``, ``, ``, true},
   331  	{`foo`, `foo`, `foo`, true},
   332  	{`foo\.\$`, `foo\\\.\\\$`, `foo.$`, true}, // has meta but no operator
   333  	{`foo.\$`, `foo\.\\\$`, `foo`, false},     // has escaped operators and real operators
   334  	{`!@#$%^&*()_+-=[{]}\|,<.>/?~`, `!@#\$%\^&\*\(\)_\+-=\[\{\]\}\\\|,<\.>/\?~`, `!@#`, false},
   335  }
   336  
   337  func TestQuoteMeta(t *testing.T) {
   338  	for _, tc := range metaTests {
   339  		// Verify that QuoteMeta returns the expected string.
   340  		quoted := QuoteMeta(tc.pattern)
   341  		if quoted != tc.output {
   342  			t.Errorf("QuoteMeta(`%s`) = `%s`; want `%s`",
   343  				tc.pattern, quoted, tc.output)
   344  			continue
   345  		}
   346  
   347  		// Verify that the quoted string is in fact treated as expected
   348  		// by Compile -- i.e. that it matches the original, unquoted string.
   349  		if tc.pattern != "" {
   350  			re, err := Compile(quoted)
   351  			if err != nil {
   352  				t.Errorf("Unexpected error compiling QuoteMeta(`%s`): %v", tc.pattern, err)
   353  				continue
   354  			}
   355  			src := "abc" + tc.pattern + "def"
   356  			repl := "xyz"
   357  			replaced := re.ReplaceAllString(src, repl)
   358  			expected := "abcxyzdef"
   359  			if replaced != expected {
   360  				t.Errorf("QuoteMeta(`%s`).Replace(`%s`,`%s`) = `%s`; want `%s`",
   361  					tc.pattern, src, repl, replaced, expected)
   362  			}
   363  		}
   364  	}
   365  }
   366  
   367  func TestLiteralPrefix(t *testing.T) {
   368  	for _, tc := range metaTests {
   369  		// Literal method needs to scan the pattern.
   370  		re := MustCompile(tc.pattern)
   371  		str, complete := re.LiteralPrefix()
   372  		if complete != tc.isLiteral {
   373  			t.Errorf("LiteralPrefix(`%s`) = %t; want %t", tc.pattern, complete, tc.isLiteral)
   374  		}
   375  		if str != tc.literal {
   376  			t.Errorf("LiteralPrefix(`%s`) = `%s`; want `%s`", tc.pattern, str, tc.literal)
   377  		}
   378  	}
   379  }
   380  
   381  type subexpCase struct {
   382  	input string
   383  	num   int
   384  	names []string
   385  }
   386  
   387  var subexpCases = []subexpCase{
   388  	{``, 0, nil},
   389  	{`.*`, 0, nil},
   390  	{`abba`, 0, nil},
   391  	{`ab(b)a`, 1, []string{"", ""}},
   392  	{`ab(.*)a`, 1, []string{"", ""}},
   393  	{`(.*)ab(.*)a`, 2, []string{"", "", ""}},
   394  	{`(.*)(ab)(.*)a`, 3, []string{"", "", "", ""}},
   395  	{`(.*)((a)b)(.*)a`, 4, []string{"", "", "", "", ""}},
   396  	{`(.*)(\(ab)(.*)a`, 3, []string{"", "", "", ""}},
   397  	{`(.*)(\(a\)b)(.*)a`, 3, []string{"", "", "", ""}},
   398  	{`(?P<foo>.*)(?P<bar>(a)b)(?P<foo>.*)a`, 4, []string{"", "foo", "bar", "", "foo"}},
   399  }
   400  
   401  func TestSubexp(t *testing.T) {
   402  	for _, c := range subexpCases {
   403  		re := MustCompile(c.input)
   404  		n := re.NumSubexp()
   405  		if n != c.num {
   406  			t.Errorf("%q: NumSubexp = %d, want %d", c.input, n, c.num)
   407  			continue
   408  		}
   409  		names := re.SubexpNames()
   410  		if len(names) != 1+n {
   411  			t.Errorf("%q: len(SubexpNames) = %d, want %d", c.input, len(names), n)
   412  			continue
   413  		}
   414  		if c.names != nil {
   415  			for i := 0; i < 1+n; i++ {
   416  				if names[i] != c.names[i] {
   417  					t.Errorf("%q: SubexpNames[%d] = %q, want %q", c.input, i, names[i], c.names[i])
   418  				}
   419  			}
   420  		}
   421  	}
   422  }
   423  
   424  var splitTests = []struct {
   425  	s   string
   426  	r   string
   427  	n   int
   428  	out []string
   429  }{
   430  	{"foo:and:bar", ":", -1, []string{"foo", "and", "bar"}},
   431  	{"foo:and:bar", ":", 1, []string{"foo:and:bar"}},
   432  	{"foo:and:bar", ":", 2, []string{"foo", "and:bar"}},
   433  	{"foo:and:bar", "foo", -1, []string{"", ":and:bar"}},
   434  	{"foo:and:bar", "bar", -1, []string{"foo:and:", ""}},
   435  	{"foo:and:bar", "baz", -1, []string{"foo:and:bar"}},
   436  	{"baabaab", "a", -1, []string{"b", "", "b", "", "b"}},
   437  	{"baabaab", "a*", -1, []string{"b", "b", "b"}},
   438  	{"baabaab", "ba*", -1, []string{"", "", "", ""}},
   439  	{"foobar", "f*b*", -1, []string{"", "o", "o", "a", "r"}},
   440  	{"foobar", "f+.*b+", -1, []string{"", "ar"}},
   441  	{"foobooboar", "o{2}", -1, []string{"f", "b", "boar"}},
   442  	{"a,b,c,d,e,f", ",", 3, []string{"a", "b", "c,d,e,f"}},
   443  	{"a,b,c,d,e,f", ",", 0, nil},
   444  	{",", ",", -1, []string{"", ""}},
   445  	{",,,", ",", -1, []string{"", "", "", ""}},
   446  	{"", ",", -1, []string{""}},
   447  	{"", ".*", -1, []string{""}},
   448  	{"", ".+", -1, []string{""}},
   449  	{"", "", -1, []string{}},
   450  	{"foobar", "", -1, []string{"f", "o", "o", "b", "a", "r"}},
   451  	{"abaabaccadaaae", "a*", 5, []string{"", "b", "b", "c", "cadaaae"}},
   452  	{":x:y:z:", ":", -1, []string{"", "x", "y", "z", ""}},
   453  }
   454  
   455  func TestSplit(t *testing.T) {
   456  	for i, test := range splitTests {
   457  		re, err := Compile(test.r)
   458  		if err != nil {
   459  			t.Errorf("#%d: %q: compile error: %s", i, test.r, err.Error())
   460  			continue
   461  		}
   462  
   463  		split := re.Split(test.s, test.n)
   464  		if !reflect.DeepEqual(split, test.out) {
   465  			t.Errorf("#%d: %q: got %q; want %q", i, test.r, split, test.out)
   466  		}
   467  
   468  		if QuoteMeta(test.r) == test.r {
   469  			strsplit := strings.SplitN(test.s, test.r, test.n)
   470  			if !reflect.DeepEqual(split, strsplit) {
   471  				t.Errorf("#%d: Split(%q, %q, %d): regexp vs strings mismatch\nregexp=%q\nstrings=%q", i, test.s, test.r, test.n, split, strsplit)
   472  			}
   473  		}
   474  	}
   475  }
   476  
   477  // Check that one-pass cutoff does trigger.
   478  func TestOnePassCutoff(t *testing.T) {
   479  	re, err := syntax.Parse(`^x{1,1000}y{1,1000}$`, syntax.Perl)
   480  	if err != nil {
   481  		t.Fatalf("parse: %v", err)
   482  	}
   483  	p, err := syntax.Compile(re.Simplify())
   484  	if err != nil {
   485  		t.Fatalf("compile: %v", err)
   486  	}
   487  	if compileOnePass(p) != notOnePass {
   488  		t.Fatalf("makeOnePass succeeded; wanted notOnePass")
   489  	}
   490  }
   491  
   492  func BenchmarkLiteral(b *testing.B) {
   493  	x := strings.Repeat("x", 50) + "y"
   494  	b.StopTimer()
   495  	re := MustCompile("y")
   496  	b.StartTimer()
   497  	for i := 0; i < b.N; i++ {
   498  		if !re.MatchString(x) {
   499  			b.Fatalf("no match!")
   500  		}
   501  	}
   502  }
   503  
   504  func BenchmarkNotLiteral(b *testing.B) {
   505  	x := strings.Repeat("x", 50) + "y"
   506  	b.StopTimer()
   507  	re := MustCompile(".y")
   508  	b.StartTimer()
   509  	for i := 0; i < b.N; i++ {
   510  		if !re.MatchString(x) {
   511  			b.Fatalf("no match!")
   512  		}
   513  	}
   514  }
   515  
   516  func BenchmarkMatchClass(b *testing.B) {
   517  	b.StopTimer()
   518  	x := strings.Repeat("xxxx", 20) + "w"
   519  	re := MustCompile("[abcdw]")
   520  	b.StartTimer()
   521  	for i := 0; i < b.N; i++ {
   522  		if !re.MatchString(x) {
   523  			b.Fatalf("no match!")
   524  		}
   525  	}
   526  }
   527  
   528  func BenchmarkMatchClass_InRange(b *testing.B) {
   529  	b.StopTimer()
   530  	// 'b' is between 'a' and 'c', so the charclass
   531  	// range checking is no help here.
   532  	x := strings.Repeat("bbbb", 20) + "c"
   533  	re := MustCompile("[ac]")
   534  	b.StartTimer()
   535  	for i := 0; i < b.N; i++ {
   536  		if !re.MatchString(x) {
   537  			b.Fatalf("no match!")
   538  		}
   539  	}
   540  }
   541  
   542  func BenchmarkReplaceAll(b *testing.B) {
   543  	x := "abcdefghijklmnopqrstuvwxyz"
   544  	b.StopTimer()
   545  	re := MustCompile("[cjrw]")
   546  	b.StartTimer()
   547  	for i := 0; i < b.N; i++ {
   548  		re.ReplaceAllString(x, "")
   549  	}
   550  }
   551  
   552  func BenchmarkAnchoredLiteralShortNonMatch(b *testing.B) {
   553  	b.StopTimer()
   554  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   555  	re := MustCompile("^zbc(d|e)")
   556  	b.StartTimer()
   557  	for i := 0; i < b.N; i++ {
   558  		re.Match(x)
   559  	}
   560  }
   561  
   562  func BenchmarkAnchoredLiteralLongNonMatch(b *testing.B) {
   563  	b.StopTimer()
   564  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   565  	for i := 0; i < 15; i++ {
   566  		x = append(x, x...)
   567  	}
   568  	re := MustCompile("^zbc(d|e)")
   569  	b.StartTimer()
   570  	for i := 0; i < b.N; i++ {
   571  		re.Match(x)
   572  	}
   573  }
   574  
   575  func BenchmarkAnchoredShortMatch(b *testing.B) {
   576  	b.StopTimer()
   577  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   578  	re := MustCompile("^.bc(d|e)")
   579  	b.StartTimer()
   580  	for i := 0; i < b.N; i++ {
   581  		re.Match(x)
   582  	}
   583  }
   584  
   585  func BenchmarkAnchoredLongMatch(b *testing.B) {
   586  	b.StopTimer()
   587  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   588  	for i := 0; i < 15; i++ {
   589  		x = append(x, x...)
   590  	}
   591  	re := MustCompile("^.bc(d|e)")
   592  	b.StartTimer()
   593  	for i := 0; i < b.N; i++ {
   594  		re.Match(x)
   595  	}
   596  }
   597  
   598  func BenchmarkOnePassShortA(b *testing.B) {
   599  	b.StopTimer()
   600  	x := []byte("abcddddddeeeededd")
   601  	re := MustCompile("^.bc(d|e)*$")
   602  	b.StartTimer()
   603  	for i := 0; i < b.N; i++ {
   604  		re.Match(x)
   605  	}
   606  }
   607  
   608  func BenchmarkNotOnePassShortA(b *testing.B) {
   609  	b.StopTimer()
   610  	x := []byte("abcddddddeeeededd")
   611  	re := MustCompile(".bc(d|e)*$")
   612  	b.StartTimer()
   613  	for i := 0; i < b.N; i++ {
   614  		re.Match(x)
   615  	}
   616  }
   617  
   618  func BenchmarkOnePassShortB(b *testing.B) {
   619  	b.StopTimer()
   620  	x := []byte("abcddddddeeeededd")
   621  	re := MustCompile("^.bc(?:d|e)*$")
   622  	b.StartTimer()
   623  	for i := 0; i < b.N; i++ {
   624  		re.Match(x)
   625  	}
   626  }
   627  
   628  func BenchmarkNotOnePassShortB(b *testing.B) {
   629  	b.StopTimer()
   630  	x := []byte("abcddddddeeeededd")
   631  	re := MustCompile(".bc(?:d|e)*$")
   632  	b.StartTimer()
   633  	for i := 0; i < b.N; i++ {
   634  		re.Match(x)
   635  	}
   636  }
   637  
   638  func BenchmarkOnePassLongPrefix(b *testing.B) {
   639  	b.StopTimer()
   640  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   641  	re := MustCompile("^abcdefghijklmnopqrstuvwxyz.*$")
   642  	b.StartTimer()
   643  	for i := 0; i < b.N; i++ {
   644  		re.Match(x)
   645  	}
   646  }
   647  
   648  func BenchmarkOnePassLongNotPrefix(b *testing.B) {
   649  	b.StopTimer()
   650  	x := []byte("abcdefghijklmnopqrstuvwxyz")
   651  	re := MustCompile("^.bcdefghijklmnopqrstuvwxyz.*$")
   652  	b.StartTimer()
   653  	for i := 0; i < b.N; i++ {
   654  		re.Match(x)
   655  	}
   656  }