| // Copyright 2010 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. |
| |
| package regexp |
| |
| import ( |
| "bufio" |
| "compress/bzip2" |
| "fmt" |
| "io" |
| "os" |
| "path/filepath" |
| "regexp/syntax" |
| "strconv" |
| "strings" |
| "testing" |
| "unicode/utf8" |
| ) |
| |
| // TestRE2 tests this package's regexp API against test cases |
| // considered during RE2's exhaustive tests, which run all possible |
| // regexps over a given set of atoms and operators, up to a given |
| // complexity, over all possible strings over a given alphabet, |
| // up to a given size. Rather than try to link with RE2, we read a |
| // log file containing the test cases and the expected matches. |
| // The log file, re2.txt, is generated by running 'make exhaustive-log' |
| // in the open source RE2 distribution. http://code.google.com/p/re2/ |
| // |
| // The test file format is a sequence of stanzas like: |
| // |
| // strings |
| // "abc" |
| // "123x" |
| // regexps |
| // "[a-z]+" |
| // 0-3;0-3 |
| // -;- |
| // "([0-9])([0-9])([0-9])" |
| // -;- |
| // -;0-3 0-1 1-2 2-3 |
| // |
| // The stanza begins by defining a set of strings, quoted |
| // using Go double-quote syntax, one per line. Then the |
| // regexps section gives a sequence of regexps to run on |
| // the strings. In the block that follows a regexp, each line |
| // gives the semicolon-separated match results of running |
| // the regexp on the corresponding string. |
| // Each match result is either a single -, meaning no match, or a |
| // space-separated sequence of pairs giving the match and |
| // submatch indices. An unmatched subexpression formats |
| // its pair as a single - (not illustrated above). For now |
| // each regexp run produces two match results, one for a |
| // ``full match'' that restricts the regexp to matching the entire |
| // string or nothing, and one for a ``partial match'' that gives |
| // the leftmost first match found in the string. |
| // |
| // Lines beginning with # are comments. Lines beginning with |
| // a capital letter are test names printed during RE2's test suite |
| // and are echoed into t but otherwise ignored. |
| // |
| // At time of writing, re2.txt is 32 MB but compresses to 760 kB, |
| // so we store re2.txt.gz in the repository and decompress it on the fly. |
| // |
| func TestRE2Search(t *testing.T) { |
| testRE2(t, "testdata/re2-search.txt") |
| } |
| |
| func testRE2(t *testing.T, file string) { |
| f, err := os.Open(file) |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer f.Close() |
| var txt io.Reader |
| if strings.HasSuffix(file, ".bz2") { |
| z := bzip2.NewReader(f) |
| txt = z |
| file = file[:len(file)-len(".bz2")] // for error messages |
| } else { |
| txt = f |
| } |
| lineno := 0 |
| scanner := bufio.NewScanner(txt) |
| var ( |
| str []string |
| input []string |
| inStrings bool |
| re *Regexp |
| refull *Regexp |
| nfail int |
| ncase int |
| ) |
| for lineno := 1; scanner.Scan(); lineno++ { |
| line := scanner.Text() |
| switch { |
| case line == "": |
| t.Fatalf("%s:%d: unexpected blank line", file, lineno) |
| case line[0] == '#': |
| continue |
| case 'A' <= line[0] && line[0] <= 'Z': |
| // Test name. |
| t.Logf("%s\n", line) |
| continue |
| case line == "strings": |
| str = str[:0] |
| inStrings = true |
| case line == "regexps": |
| inStrings = false |
| case line[0] == '"': |
| q, err := strconv.Unquote(line) |
| if err != nil { |
| // Fatal because we'll get out of sync. |
| t.Fatalf("%s:%d: unquote %s: %v", file, lineno, line, err) |
| } |
| if inStrings { |
| str = append(str, q) |
| continue |
| } |
| // Is a regexp. |
| if len(input) != 0 { |
| t.Fatalf("%s:%d: out of sync: have %d strings left before %#q", file, lineno, len(input), q) |
| } |
| re, err = tryCompile(q) |
| if err != nil { |
| if err.Error() == "error parsing regexp: invalid escape sequence: `\\C`" { |
| // We don't and likely never will support \C; keep going. |
| continue |
| } |
| t.Errorf("%s:%d: compile %#q: %v", file, lineno, q, err) |
| if nfail++; nfail >= 100 { |
| t.Fatalf("stopping after %d errors", nfail) |
| } |
| continue |
| } |
| full := `\A(?:` + q + `)\z` |
| refull, err = tryCompile(full) |
| if err != nil { |
| // Fatal because q worked, so this should always work. |
| t.Fatalf("%s:%d: compile full %#q: %v", file, lineno, full, err) |
| } |
| input = str |
| case line[0] == '-' || '0' <= line[0] && line[0] <= '9': |
| // A sequence of match results. |
| ncase++ |
| if re == nil { |
| // Failed to compile: skip results. |
| continue |
| } |
| if len(input) == 0 { |
| t.Fatalf("%s:%d: out of sync: no input remaining", file, lineno) |
| } |
| var text string |
| text, input = input[0], input[1:] |
| if !isSingleBytes(text) && strings.Contains(re.String(), `\B`) { |
| // RE2's \B considers every byte position, |
| // so it sees 'not word boundary' in the |
| // middle of UTF-8 sequences. This package |
| // only considers the positions between runes, |
| // so it disagrees. Skip those cases. |
| continue |
| } |
| res := strings.Split(line, ";") |
| if len(res) != len(run) { |
| t.Fatalf("%s:%d: have %d test results, want %d", file, lineno, len(res), len(run)) |
| } |
| for i := range res { |
| have, suffix := run[i](re, refull, text) |
| want := parseResult(t, file, lineno, res[i]) |
| if !same(have, want) { |
| t.Errorf("%s:%d: %#q%s.FindSubmatchIndex(%#q) = %v, want %v", file, lineno, re, suffix, text, have, want) |
| if nfail++; nfail >= 100 { |
| t.Fatalf("stopping after %d errors", nfail) |
| } |
| continue |
| } |
| b, suffix := match[i](re, refull, text) |
| if b != (want != nil) { |
| t.Errorf("%s:%d: %#q%s.MatchString(%#q) = %v, want %v", file, lineno, re, suffix, text, b, !b) |
| if nfail++; nfail >= 100 { |
| t.Fatalf("stopping after %d errors", nfail) |
| } |
| continue |
| } |
| } |
| |
| default: |
| t.Fatalf("%s:%d: out of sync: %s\n", file, lineno, line) |
| } |
| } |
| if err := scanner.Err(); err != nil { |
| t.Fatalf("%s:%d: %v", file, lineno, err) |
| } |
| if len(input) != 0 { |
| t.Fatalf("%s:%d: out of sync: have %d strings left at EOF", file, lineno, len(input)) |
| } |
| t.Logf("%d cases tested", ncase) |
| } |
| |
| var run = []func(*Regexp, *Regexp, string) ([]int, string){ |
| runFull, |
| runPartial, |
| runFullLongest, |
| runPartialLongest, |
| } |
| |
| func runFull(re, refull *Regexp, text string) ([]int, string) { |
| refull.longest = false |
| return refull.FindStringSubmatchIndex(text), "[full]" |
| } |
| |
| func runPartial(re, refull *Regexp, text string) ([]int, string) { |
| re.longest = false |
| return re.FindStringSubmatchIndex(text), "" |
| } |
| |
| func runFullLongest(re, refull *Regexp, text string) ([]int, string) { |
| refull.longest = true |
| return refull.FindStringSubmatchIndex(text), "[full,longest]" |
| } |
| |
| func runPartialLongest(re, refull *Regexp, text string) ([]int, string) { |
| re.longest = true |
| return re.FindStringSubmatchIndex(text), "[longest]" |
| } |
| |
| var match = []func(*Regexp, *Regexp, string) (bool, string){ |
| matchFull, |
| matchPartial, |
| matchFullLongest, |
| matchPartialLongest, |
| } |
| |
| func matchFull(re, refull *Regexp, text string) (bool, string) { |
| refull.longest = false |
| return refull.MatchString(text), "[full]" |
| } |
| |
| func matchPartial(re, refull *Regexp, text string) (bool, string) { |
| re.longest = false |
| return re.MatchString(text), "" |
| } |
| |
| func matchFullLongest(re, refull *Regexp, text string) (bool, string) { |
| refull.longest = true |
| return refull.MatchString(text), "[full,longest]" |
| } |
| |
| func matchPartialLongest(re, refull *Regexp, text string) (bool, string) { |
| re.longest = true |
| return re.MatchString(text), "[longest]" |
| } |
| |
| func isSingleBytes(s string) bool { |
| for _, c := range s { |
| if c >= utf8.RuneSelf { |
| return false |
| } |
| } |
| return true |
| } |
| |
| func tryCompile(s string) (re *Regexp, err error) { |
| // Protect against panic during Compile. |
| defer func() { |
| if r := recover(); r != nil { |
| err = fmt.Errorf("panic: %v", r) |
| } |
| }() |
| return Compile(s) |
| } |
| |
| func parseResult(t *testing.T, file string, lineno int, res string) []int { |
| // A single - indicates no match. |
| if res == "-" { |
| return nil |
| } |
| // Otherwise, a space-separated list of pairs. |
| n := 1 |
| for j := 0; j < len(res); j++ { |
| if res[j] == ' ' { |
| n++ |
| } |
| } |
| out := make([]int, 2*n) |
| i := 0 |
| n = 0 |
| for j := 0; j <= len(res); j++ { |
| if j == len(res) || res[j] == ' ' { |
| // Process a single pair. - means no submatch. |
| pair := res[i:j] |
| if pair == "-" { |
| out[n] = -1 |
| out[n+1] = -1 |
| } else { |
| k := strings.Index(pair, "-") |
| if k < 0 { |
| t.Fatalf("%s:%d: invalid pair %s", file, lineno, pair) |
| } |
| lo, err1 := strconv.Atoi(pair[:k]) |
| hi, err2 := strconv.Atoi(pair[k+1:]) |
| if err1 != nil || err2 != nil || lo > hi { |
| t.Fatalf("%s:%d: invalid pair %s", file, lineno, pair) |
| } |
| out[n] = lo |
| out[n+1] = hi |
| } |
| n += 2 |
| i = j + 1 |
| } |
| } |
| return out |
| } |
| |
| func same(x, y []int) bool { |
| if len(x) != len(y) { |
| return false |
| } |
| for i, xi := range x { |
| if xi != y[i] { |
| return false |
| } |
| } |
| return true |
| } |
| |
| // TestFowler runs this package's regexp API against the |
| // POSIX regular expression tests collected by Glenn Fowler |
| // at http://www2.research.att.com/~gsf/testregex/. |
| func TestFowler(t *testing.T) { |
| files, err := filepath.Glob("testdata/*.dat") |
| if err != nil { |
| t.Fatal(err) |
| } |
| for _, file := range files { |
| t.Log(file) |
| testFowler(t, file) |
| } |
| } |
| |
| var notab = MustCompilePOSIX(`[^\t]+`) |
| |
| func testFowler(t *testing.T, file string) { |
| f, err := os.Open(file) |
| if err != nil { |
| t.Error(err) |
| return |
| } |
| defer f.Close() |
| b := bufio.NewReader(f) |
| lineno := 0 |
| lastRegexp := "" |
| Reading: |
| for { |
| lineno++ |
| line, err := b.ReadString('\n') |
| if err != nil { |
| if err != io.EOF { |
| t.Errorf("%s:%d: %v", file, lineno, err) |
| } |
| break Reading |
| } |
| |
| // http://www2.research.att.com/~gsf/man/man1/testregex.html |
| // |
| // INPUT FORMAT |
| // Input lines may be blank, a comment beginning with #, or a test |
| // specification. A specification is five fields separated by one |
| // or more tabs. NULL denotes the empty string and NIL denotes the |
| // 0 pointer. |
| if line[0] == '#' || line[0] == '\n' { |
| continue Reading |
| } |
| line = line[:len(line)-1] |
| field := notab.FindAllString(line, -1) |
| for i, f := range field { |
| if f == "NULL" { |
| field[i] = "" |
| } |
| if f == "NIL" { |
| t.Logf("%s:%d: skip: %s", file, lineno, line) |
| continue Reading |
| } |
| } |
| if len(field) == 0 { |
| continue Reading |
| } |
| |
| // Field 1: the regex(3) flags to apply, one character per REG_feature |
| // flag. The test is skipped if REG_feature is not supported by the |
| // implementation. If the first character is not [BEASKLP] then the |
| // specification is a global control line. One or more of [BEASKLP] may be |
| // specified; the test will be repeated for each mode. |
| // |
| // B basic BRE (grep, ed, sed) |
| // E REG_EXTENDED ERE (egrep) |
| // A REG_AUGMENTED ARE (egrep with negation) |
| // S REG_SHELL SRE (sh glob) |
| // K REG_SHELL|REG_AUGMENTED KRE (ksh glob) |
| // L REG_LITERAL LRE (fgrep) |
| // |
| // a REG_LEFT|REG_RIGHT implicit ^...$ |
| // b REG_NOTBOL lhs does not match ^ |
| // c REG_COMMENT ignore space and #...\n |
| // d REG_SHELL_DOT explicit leading . match |
| // e REG_NOTEOL rhs does not match $ |
| // f REG_MULTIPLE multiple \n separated patterns |
| // g FNM_LEADING_DIR testfnmatch only -- match until / |
| // h REG_MULTIREF multiple digit backref |
| // i REG_ICASE ignore case |
| // j REG_SPAN . matches \n |
| // k REG_ESCAPE \ to ecape [...] delimiter |
| // l REG_LEFT implicit ^... |
| // m REG_MINIMAL minimal match |
| // n REG_NEWLINE explicit \n match |
| // o REG_ENCLOSED (|&) magic inside [@|&](...) |
| // p REG_SHELL_PATH explicit / match |
| // q REG_DELIMITED delimited pattern |
| // r REG_RIGHT implicit ...$ |
| // s REG_SHELL_ESCAPED \ not special |
| // t REG_MUSTDELIM all delimiters must be specified |
| // u standard unspecified behavior -- errors not counted |
| // v REG_CLASS_ESCAPE \ special inside [...] |
| // w REG_NOSUB no subexpression match array |
| // x REG_LENIENT let some errors slide |
| // y REG_LEFT regexec() implicit ^... |
| // z REG_NULL NULL subexpressions ok |
| // $ expand C \c escapes in fields 2 and 3 |
| // / field 2 is a regsubcomp() expression |
| // = field 3 is a regdecomp() expression |
| // |
| // Field 1 control lines: |
| // |
| // C set LC_COLLATE and LC_CTYPE to locale in field 2 |
| // |
| // ?test ... output field 5 if passed and != EXPECTED, silent otherwise |
| // &test ... output field 5 if current and previous passed |
| // |test ... output field 5 if current passed and previous failed |
| // ; ... output field 2 if previous failed |
| // {test ... skip if failed until } |
| // } end of skip |
| // |
| // : comment comment copied as output NOTE |
| // :comment:test :comment: ignored |
| // N[OTE] comment comment copied as output NOTE |
| // T[EST] comment comment |
| // |
| // number use number for nmatch (20 by default) |
| flag := field[0] |
| switch flag[0] { |
| case '?', '&', '|', ';', '{', '}': |
| // Ignore all the control operators. |
| // Just run everything. |
| flag = flag[1:] |
| if flag == "" { |
| continue Reading |
| } |
| case ':': |
| i := strings.Index(flag[1:], ":") |
| if i < 0 { |
| t.Logf("skip: %s", line) |
| continue Reading |
| } |
| flag = flag[1+i+1:] |
| case 'C', 'N', 'T', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': |
| t.Logf("skip: %s", line) |
| continue Reading |
| } |
| |
| // Can check field count now that we've handled the myriad comment formats. |
| if len(field) < 4 { |
| t.Errorf("%s:%d: too few fields: %s", file, lineno, line) |
| continue Reading |
| } |
| |
| // Expand C escapes (a.k.a. Go escapes). |
| if strings.Contains(flag, "$") { |
| f := `"` + field[1] + `"` |
| if field[1], err = strconv.Unquote(f); err != nil { |
| t.Errorf("%s:%d: cannot unquote %s", file, lineno, f) |
| } |
| f = `"` + field[2] + `"` |
| if field[2], err = strconv.Unquote(f); err != nil { |
| t.Errorf("%s:%d: cannot unquote %s", file, lineno, f) |
| } |
| } |
| |
| // Field 2: the regular expression pattern; SAME uses the pattern from |
| // the previous specification. |
| // |
| if field[1] == "SAME" { |
| field[1] = lastRegexp |
| } |
| lastRegexp = field[1] |
| |
| // Field 3: the string to match. |
| text := field[2] |
| |
| // Field 4: the test outcome... |
| ok, shouldCompile, shouldMatch, pos := parseFowlerResult(field[3]) |
| if !ok { |
| t.Errorf("%s:%d: cannot parse result %#q", file, lineno, field[3]) |
| continue Reading |
| } |
| |
| // Field 5: optional comment appended to the report. |
| |
| Testing: |
| // Run test once for each specified capital letter mode that we support. |
| for _, c := range flag { |
| pattern := field[1] |
| syn := syntax.POSIX | syntax.ClassNL |
| switch c { |
| default: |
| continue Testing |
| case 'E': |
| // extended regexp (what we support) |
| case 'L': |
| // literal |
| pattern = QuoteMeta(pattern) |
| } |
| |
| for _, c := range flag { |
| switch c { |
| case 'i': |
| syn |= syntax.FoldCase |
| } |
| } |
| |
| re, err := compile(pattern, syn, true) |
| if err != nil { |
| if shouldCompile { |
| t.Errorf("%s:%d: %#q did not compile", file, lineno, pattern) |
| } |
| continue Testing |
| } |
| if !shouldCompile { |
| t.Errorf("%s:%d: %#q should not compile", file, lineno, pattern) |
| continue Testing |
| } |
| match := re.MatchString(text) |
| if match != shouldMatch { |
| t.Errorf("%s:%d: %#q.Match(%#q) = %v, want %v", file, lineno, pattern, text, match, shouldMatch) |
| continue Testing |
| } |
| have := re.FindStringSubmatchIndex(text) |
| if (len(have) > 0) != match { |
| t.Errorf("%s:%d: %#q.Match(%#q) = %v, but %#q.FindSubmatchIndex(%#q) = %v", file, lineno, pattern, text, match, pattern, text, have) |
| continue Testing |
| } |
| if len(have) > len(pos) { |
| have = have[:len(pos)] |
| } |
| if !same(have, pos) { |
| t.Errorf("%s:%d: %#q.FindSubmatchIndex(%#q) = %v, want %v", file, lineno, pattern, text, have, pos) |
| } |
| } |
| } |
| } |
| |
| func parseFowlerResult(s string) (ok, compiled, matched bool, pos []int) { |
| // Field 4: the test outcome. This is either one of the posix error |
| // codes (with REG_ omitted) or the match array, a list of (m,n) |
| // entries with m and n being first and last+1 positions in the |
| // field 3 string, or NULL if REG_NOSUB is in effect and success |
| // is expected. BADPAT is acceptable in place of any regcomp(3) |
| // error code. The match[] array is initialized to (-2,-2) before |
| // each test. All array elements from 0 to nmatch-1 must be specified |
| // in the outcome. Unspecified endpoints (offset -1) are denoted by ?. |
| // Unset endpoints (offset -2) are denoted by X. {x}(o:n) denotes a |
| // matched (?{...}) expression, where x is the text enclosed by {...}, |
| // o is the expression ordinal counting from 1, and n is the length of |
| // the unmatched portion of the subject string. If x starts with a |
| // number then that is the return value of re_execf(), otherwise 0 is |
| // returned. |
| switch { |
| case s == "": |
| // Match with no position information. |
| ok = true |
| compiled = true |
| matched = true |
| return |
| case s == "NOMATCH": |
| // Match failure. |
| ok = true |
| compiled = true |
| matched = false |
| return |
| case 'A' <= s[0] && s[0] <= 'Z': |
| // All the other error codes are compile errors. |
| ok = true |
| compiled = false |
| return |
| } |
| compiled = true |
| |
| var x []int |
| for s != "" { |
| var end byte = ')' |
| if len(x)%2 == 0 { |
| if s[0] != '(' { |
| ok = false |
| return |
| } |
| s = s[1:] |
| end = ',' |
| } |
| i := 0 |
| for i < len(s) && s[i] != end { |
| i++ |
| } |
| if i == 0 || i == len(s) { |
| ok = false |
| return |
| } |
| var v = -1 |
| var err error |
| if s[:i] != "?" { |
| v, err = strconv.Atoi(s[:i]) |
| if err != nil { |
| ok = false |
| return |
| } |
| } |
| x = append(x, v) |
| s = s[i+1:] |
| } |
| if len(x)%2 != 0 { |
| ok = false |
| return |
| } |
| ok = true |
| matched = true |
| pos = x |
| return |
| } |
| |
| var text []byte |
| |
| func makeText(n int) []byte { |
| if len(text) >= n { |
| return text[:n] |
| } |
| text = make([]byte, n) |
| x := ^uint32(0) |
| for i := range text { |
| x += x |
| x ^= 1 |
| if int32(x) < 0 { |
| x ^= 0x88888eef |
| } |
| if x%31 == 0 { |
| text[i] = '\n' |
| } else { |
| text[i] = byte(x%(0x7E+1-0x20) + 0x20) |
| } |
| } |
| return text |
| } |
| |
| func benchmark(b *testing.B, re string, n int) { |
| r := MustCompile(re) |
| t := makeText(n) |
| b.ResetTimer() |
| b.SetBytes(int64(n)) |
| for i := 0; i < b.N; i++ { |
| if r.Match(t) { |
| b.Fatal("match!") |
| } |
| } |
| } |
| |
| const ( |
| easy0 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ$" |
| easy1 = "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$" |
| medium = "[XYZ]ABCDEFGHIJKLMNOPQRSTUVWXYZ$" |
| hard = "[ -~]*ABCDEFGHIJKLMNOPQRSTUVWXYZ$" |
| parens = "([ -~])*(A)(B)(C)(D)(E)(F)(G)(H)(I)(J)(K)(L)(M)" + |
| "(N)(O)(P)(Q)(R)(S)(T)(U)(V)(W)(X)(Y)(Z)$" |
| ) |
| |
| func BenchmarkMatchEasy0_32(b *testing.B) { benchmark(b, easy0, 32<<0) } |
| func BenchmarkMatchEasy0_1K(b *testing.B) { benchmark(b, easy0, 1<<10) } |
| func BenchmarkMatchEasy0_32K(b *testing.B) { benchmark(b, easy0, 32<<10) } |
| func BenchmarkMatchEasy0_1M(b *testing.B) { benchmark(b, easy0, 1<<20) } |
| func BenchmarkMatchEasy0_32M(b *testing.B) { benchmark(b, easy0, 32<<20) } |
| func BenchmarkMatchEasy1_32(b *testing.B) { benchmark(b, easy1, 32<<0) } |
| func BenchmarkMatchEasy1_1K(b *testing.B) { benchmark(b, easy1, 1<<10) } |
| func BenchmarkMatchEasy1_32K(b *testing.B) { benchmark(b, easy1, 32<<10) } |
| func BenchmarkMatchEasy1_1M(b *testing.B) { benchmark(b, easy1, 1<<20) } |
| func BenchmarkMatchEasy1_32M(b *testing.B) { benchmark(b, easy1, 32<<20) } |
| func BenchmarkMatchMedium_32(b *testing.B) { benchmark(b, medium, 32<<0) } |
| func BenchmarkMatchMedium_1K(b *testing.B) { benchmark(b, medium, 1<<10) } |
| func BenchmarkMatchMedium_32K(b *testing.B) { benchmark(b, medium, 32<<10) } |
| func BenchmarkMatchMedium_1M(b *testing.B) { benchmark(b, medium, 1<<20) } |
| func BenchmarkMatchMedium_32M(b *testing.B) { benchmark(b, medium, 32<<20) } |
| func BenchmarkMatchHard_32(b *testing.B) { benchmark(b, hard, 32<<0) } |
| func BenchmarkMatchHard_1K(b *testing.B) { benchmark(b, hard, 1<<10) } |
| func BenchmarkMatchHard_32K(b *testing.B) { benchmark(b, hard, 32<<10) } |
| func BenchmarkMatchHard_1M(b *testing.B) { benchmark(b, hard, 1<<20) } |
| func BenchmarkMatchHard_32M(b *testing.B) { benchmark(b, hard, 32<<20) } |
| |
| func TestLongest(t *testing.T) { |
| re, err := Compile(`a(|b)`) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if g, w := re.FindString("ab"), "a"; g != w { |
| t.Errorf("first match was %q, want %q", g, w) |
| } |
| re.Longest() |
| if g, w := re.FindString("ab"), "ab"; g != w { |
| t.Errorf("longest match was %q, want %q", g, w) |
| } |
| } |
