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Diffstat (limited to 'gcc-4.8.1/libgo/go/regexp/regexp.go')
| -rw-r--r-- | gcc-4.8.1/libgo/go/regexp/regexp.go | 1099 |
1 files changed, 0 insertions, 1099 deletions
diff --git a/gcc-4.8.1/libgo/go/regexp/regexp.go b/gcc-4.8.1/libgo/go/regexp/regexp.go deleted file mode 100644 index c516a1566..000000000 --- a/gcc-4.8.1/libgo/go/regexp/regexp.go +++ /dev/null @@ -1,1099 +0,0 @@ -// 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. - -// Package regexp implements regular expression search. -// -// The syntax of the regular expressions accepted is the same -// general syntax used by Perl, Python, and other languages. -// More precisely, it is the syntax accepted by RE2 and described at -// http://code.google.com/p/re2/wiki/Syntax, except for \C. -// -// All characters are UTF-8-encoded code points. -// -// There are 16 methods of Regexp that match a regular expression and identify -// the matched text. Their names are matched by this regular expression: -// -// Find(All)?(String)?(Submatch)?(Index)? -// -// If 'All' is present, the routine matches successive non-overlapping -// matches of the entire expression. Empty matches abutting a preceding -// match are ignored. The return value is a slice containing the successive -// return values of the corresponding non-'All' routine. These routines take -// an extra integer argument, n; if n >= 0, the function returns at most n -// matches/submatches. -// -// If 'String' is present, the argument is a string; otherwise it is a slice -// of bytes; return values are adjusted as appropriate. -// -// If 'Submatch' is present, the return value is a slice identifying the -// successive submatches of the expression. Submatches are matches of -// parenthesized subexpressions within the regular expression, numbered from -// left to right in order of opening parenthesis. Submatch 0 is the match of -// the entire expression, submatch 1 the match of the first parenthesized -// subexpression, and so on. -// -// If 'Index' is present, matches and submatches are identified by byte index -// pairs within the input string: result[2*n:2*n+1] identifies the indexes of -// the nth submatch. The pair for n==0 identifies the match of the entire -// expression. If 'Index' is not present, the match is identified by the -// text of the match/submatch. If an index is negative, it means that -// subexpression did not match any string in the input. -// -// There is also a subset of the methods that can be applied to text read -// from a RuneReader: -// -// MatchReader, FindReaderIndex, FindReaderSubmatchIndex -// -// This set may grow. Note that regular expression matches may need to -// examine text beyond the text returned by a match, so the methods that -// match text from a RuneReader may read arbitrarily far into the input -// before returning. -// -// (There are a few other methods that do not match this pattern.) -// -package regexp - -import ( - "bytes" - "io" - "regexp/syntax" - "strconv" - "strings" - "sync" - "unicode" - "unicode/utf8" -) - -var debug = false - -// Regexp is the representation of a compiled regular expression. -// The public interface is entirely through methods. -// A Regexp is safe for concurrent use by multiple goroutines. -type Regexp struct { - // read-only after Compile - expr string // as passed to Compile - prog *syntax.Prog // compiled program - prefix string // required prefix in unanchored matches - prefixBytes []byte // prefix, as a []byte - prefixComplete bool // prefix is the entire regexp - prefixRune rune // first rune in prefix - cond syntax.EmptyOp // empty-width conditions required at start of match - numSubexp int - subexpNames []string - longest bool - - // cache of machines for running regexp - mu sync.Mutex - machine []*machine -} - -// String returns the source text used to compile the regular expression. -func (re *Regexp) String() string { - return re.expr -} - -// Compile parses a regular expression and returns, if successful, -// a Regexp object that can be used to match against text. -// -// When matching against text, the regexp returns a match that -// begins as early as possible in the input (leftmost), and among those -// it chooses the one that a backtracking search would have found first. -// This so-called leftmost-first matching is the same semantics -// that Perl, Python, and other implementations use, although this -// package implements it without the expense of backtracking. -// For POSIX leftmost-longest matching, see CompilePOSIX. -func Compile(expr string) (*Regexp, error) { - return compile(expr, syntax.Perl, false) -} - -// CompilePOSIX is like Compile but restricts the regular expression -// to POSIX ERE (egrep) syntax and changes the match semantics to -// leftmost-longest. -// -// That is, when matching against text, the regexp returns a match that -// begins as early as possible in the input (leftmost), and among those -// it chooses a match that is as long as possible. -// This so-called leftmost-longest matching is the same semantics -// that early regular expression implementations used and that POSIX -// specifies. -// -// However, there can be multiple leftmost-longest matches, with different -// submatch choices, and here this package diverges from POSIX. -// Among the possible leftmost-longest matches, this package chooses -// the one that a backtracking search would have found first, while POSIX -// specifies that the match be chosen to maximize the length of the first -// subexpression, then the second, and so on from left to right. -// The POSIX rule is computationally prohibitive and not even well-defined. -// See http://swtch.com/~rsc/regexp/regexp2.html#posix for details. -func CompilePOSIX(expr string) (*Regexp, error) { - return compile(expr, syntax.POSIX, true) -} - -func compile(expr string, mode syntax.Flags, longest bool) (*Regexp, error) { - re, err := syntax.Parse(expr, mode) - if err != nil { - return nil, err - } - maxCap := re.MaxCap() - capNames := re.CapNames() - - re = re.Simplify() - prog, err := syntax.Compile(re) - if err != nil { - return nil, err - } - regexp := &Regexp{ - expr: expr, - prog: prog, - numSubexp: maxCap, - subexpNames: capNames, - cond: prog.StartCond(), - longest: longest, - } - regexp.prefix, regexp.prefixComplete = prog.Prefix() - if regexp.prefix != "" { - // TODO(rsc): Remove this allocation by adding - // IndexString to package bytes. - regexp.prefixBytes = []byte(regexp.prefix) - regexp.prefixRune, _ = utf8.DecodeRuneInString(regexp.prefix) - } - return regexp, nil -} - -// get returns a machine to use for matching re. -// It uses the re's machine cache if possible, to avoid -// unnecessary allocation. -func (re *Regexp) get() *machine { - re.mu.Lock() - if n := len(re.machine); n > 0 { - z := re.machine[n-1] - re.machine = re.machine[:n-1] - re.mu.Unlock() - return z - } - re.mu.Unlock() - z := progMachine(re.prog) - z.re = re - return z -} - -// put returns a machine to the re's machine cache. -// There is no attempt to limit the size of the cache, so it will -// grow to the maximum number of simultaneous matches -// run using re. (The cache empties when re gets garbage collected.) -func (re *Regexp) put(z *machine) { - re.mu.Lock() - re.machine = append(re.machine, z) - re.mu.Unlock() -} - -// MustCompile is like Compile but panics if the expression cannot be parsed. -// It simplifies safe initialization of global variables holding compiled regular -// expressions. -func MustCompile(str string) *Regexp { - regexp, error := Compile(str) - if error != nil { - panic(`regexp: Compile(` + quote(str) + `): ` + error.Error()) - } - return regexp -} - -// MustCompilePOSIX is like CompilePOSIX but panics if the expression cannot be parsed. -// It simplifies safe initialization of global variables holding compiled regular -// expressions. -func MustCompilePOSIX(str string) *Regexp { - regexp, error := CompilePOSIX(str) - if error != nil { - panic(`regexp: CompilePOSIX(` + quote(str) + `): ` + error.Error()) - } - return regexp -} - -func quote(s string) string { - if strconv.CanBackquote(s) { - return "`" + s + "`" - } - return strconv.Quote(s) -} - -// NumSubexp returns the number of parenthesized subexpressions in this Regexp. -func (re *Regexp) NumSubexp() int { - return re.numSubexp -} - -// SubexpNames returns the names of the parenthesized subexpressions -// in this Regexp. The name for the first sub-expression is names[1], -// so that if m is a match slice, the name for m[i] is SubexpNames()[i]. -// Since the Regexp as a whole cannot be named, names[0] is always -// the empty string. The slice should not be modified. -func (re *Regexp) SubexpNames() []string { - return re.subexpNames -} - -const endOfText rune = -1 - -// input abstracts different representations of the input text. It provides -// one-character lookahead. -type input interface { - step(pos int) (r rune, width int) // advance one rune - canCheckPrefix() bool // can we look ahead without losing info? - hasPrefix(re *Regexp) bool - index(re *Regexp, pos int) int - context(pos int) syntax.EmptyOp -} - -// inputString scans a string. -type inputString struct { - str string -} - -func (i *inputString) step(pos int) (rune, int) { - if pos < len(i.str) { - c := i.str[pos] - if c < utf8.RuneSelf { - return rune(c), 1 - } - return utf8.DecodeRuneInString(i.str[pos:]) - } - return endOfText, 0 -} - -func (i *inputString) canCheckPrefix() bool { - return true -} - -func (i *inputString) hasPrefix(re *Regexp) bool { - return strings.HasPrefix(i.str, re.prefix) -} - -func (i *inputString) index(re *Regexp, pos int) int { - return strings.Index(i.str[pos:], re.prefix) -} - -func (i *inputString) context(pos int) syntax.EmptyOp { - r1, r2 := endOfText, endOfText - if pos > 0 && pos <= len(i.str) { - r1, _ = utf8.DecodeLastRuneInString(i.str[:pos]) - } - if pos < len(i.str) { - r2, _ = utf8.DecodeRuneInString(i.str[pos:]) - } - return syntax.EmptyOpContext(r1, r2) -} - -// inputBytes scans a byte slice. -type inputBytes struct { - str []byte -} - -func (i *inputBytes) step(pos int) (rune, int) { - if pos < len(i.str) { - c := i.str[pos] - if c < utf8.RuneSelf { - return rune(c), 1 - } - return utf8.DecodeRune(i.str[pos:]) - } - return endOfText, 0 -} - -func (i *inputBytes) canCheckPrefix() bool { - return true -} - -func (i *inputBytes) hasPrefix(re *Regexp) bool { - return bytes.HasPrefix(i.str, re.prefixBytes) -} - -func (i *inputBytes) index(re *Regexp, pos int) int { - return bytes.Index(i.str[pos:], re.prefixBytes) -} - -func (i *inputBytes) context(pos int) syntax.EmptyOp { - r1, r2 := endOfText, endOfText - if pos > 0 && pos <= len(i.str) { - r1, _ = utf8.DecodeLastRune(i.str[:pos]) - } - if pos < len(i.str) { - r2, _ = utf8.DecodeRune(i.str[pos:]) - } - return syntax.EmptyOpContext(r1, r2) -} - -// inputReader scans a RuneReader. -type inputReader struct { - r io.RuneReader - atEOT bool - pos int -} - -func (i *inputReader) step(pos int) (rune, int) { - if !i.atEOT && pos != i.pos { - return endOfText, 0 - - } - r, w, err := i.r.ReadRune() - if err != nil { - i.atEOT = true - return endOfText, 0 - } - i.pos += w - return r, w -} - -func (i *inputReader) canCheckPrefix() bool { - return false -} - -func (i *inputReader) hasPrefix(re *Regexp) bool { - return false -} - -func (i *inputReader) index(re *Regexp, pos int) int { - return -1 -} - -func (i *inputReader) context(pos int) syntax.EmptyOp { - return 0 -} - -// LiteralPrefix returns a literal string that must begin any match -// of the regular expression re. It returns the boolean true if the -// literal string comprises the entire regular expression. -func (re *Regexp) LiteralPrefix() (prefix string, complete bool) { - return re.prefix, re.prefixComplete -} - -// MatchReader returns whether the Regexp matches the text read by the -// RuneReader. The return value is a boolean: true for match, false for no -// match. -func (re *Regexp) MatchReader(r io.RuneReader) bool { - return re.doExecute(r, nil, "", 0, 0) != nil -} - -// MatchString returns whether the Regexp matches the string s. -// The return value is a boolean: true for match, false for no match. -func (re *Regexp) MatchString(s string) bool { - return re.doExecute(nil, nil, s, 0, 0) != nil -} - -// Match returns whether the Regexp matches the byte slice b. -// The return value is a boolean: true for match, false for no match. -func (re *Regexp) Match(b []byte) bool { - return re.doExecute(nil, b, "", 0, 0) != nil -} - -// MatchReader checks whether a textual regular expression matches the text -// read by the RuneReader. More complicated queries need to use Compile and -// the full Regexp interface. -func MatchReader(pattern string, r io.RuneReader) (matched bool, error error) { - re, err := Compile(pattern) - if err != nil { - return false, err - } - return re.MatchReader(r), nil -} - -// MatchString checks whether a textual regular expression -// matches a string. More complicated queries need -// to use Compile and the full Regexp interface. -func MatchString(pattern string, s string) (matched bool, error error) { - re, err := Compile(pattern) - if err != nil { - return false, err - } - return re.MatchString(s), nil -} - -// Match checks whether a textual regular expression -// matches a byte slice. More complicated queries need -// to use Compile and the full Regexp interface. -func Match(pattern string, b []byte) (matched bool, error error) { - re, err := Compile(pattern) - if err != nil { - return false, err - } - return re.Match(b), nil -} - -// ReplaceAllString returns a copy of src, replacing matches of the Regexp -// with the replacement string repl. Inside repl, $ signs are interpreted as -// in Expand, so for instance $1 represents the text of the first submatch. -func (re *Regexp) ReplaceAllString(src, repl string) string { - n := 2 - if strings.Index(repl, "$") >= 0 { - n = 2 * (re.numSubexp + 1) - } - b := re.replaceAll(nil, src, n, func(dst []byte, match []int) []byte { - return re.expand(dst, repl, nil, src, match) - }) - return string(b) -} - -// ReplaceAllStringLiteral returns a copy of src, replacing matches of the Regexp -// with the replacement string repl. The replacement repl is substituted directly, -// without using Expand. -func (re *Regexp) ReplaceAllLiteralString(src, repl string) string { - return string(re.replaceAll(nil, src, 2, func(dst []byte, match []int) []byte { - return append(dst, repl...) - })) -} - -// ReplaceAllStringFunc returns a copy of src in which all matches of the -// Regexp have been replaced by the return value of function repl applied -// to the matched substring. The replacement returned by repl is substituted -// directly, without using Expand. -func (re *Regexp) ReplaceAllStringFunc(src string, repl func(string) string) string { - b := re.replaceAll(nil, src, 2, func(dst []byte, match []int) []byte { - return append(dst, repl(src[match[0]:match[1]])...) - }) - return string(b) -} - -func (re *Regexp) replaceAll(bsrc []byte, src string, nmatch int, repl func(dst []byte, m []int) []byte) []byte { - lastMatchEnd := 0 // end position of the most recent match - searchPos := 0 // position where we next look for a match - var buf []byte - var endPos int - if bsrc != nil { - endPos = len(bsrc) - } else { - endPos = len(src) - } - for searchPos <= endPos { - a := re.doExecute(nil, bsrc, src, searchPos, nmatch) - if len(a) == 0 { - break // no more matches - } - - // Copy the unmatched characters before this match. - if bsrc != nil { - buf = append(buf, bsrc[lastMatchEnd:a[0]]...) - } else { - buf = append(buf, src[lastMatchEnd:a[0]]...) - } - - // Now insert a copy of the replacement string, but not for a - // match of the empty string immediately after another match. - // (Otherwise, we get double replacement for patterns that - // match both empty and nonempty strings.) - if a[1] > lastMatchEnd || a[0] == 0 { - buf = repl(buf, a) - } - lastMatchEnd = a[1] - - // Advance past this match; always advance at least one character. - var width int - if bsrc != nil { - _, width = utf8.DecodeRune(bsrc[searchPos:]) - } else { - _, width = utf8.DecodeRuneInString(src[searchPos:]) - } - if searchPos+width > a[1] { - searchPos += width - } else if searchPos+1 > a[1] { - // This clause is only needed at the end of the input - // string. In that case, DecodeRuneInString returns width=0. - searchPos++ - } else { - searchPos = a[1] - } - } - - // Copy the unmatched characters after the last match. - if bsrc != nil { - buf = append(buf, bsrc[lastMatchEnd:]...) - } else { - buf = append(buf, src[lastMatchEnd:]...) - } - - return buf -} - -// ReplaceAll returns a copy of src, replacing matches of the Regexp -// with the replacement text repl. Inside repl, $ signs are interpreted as -// in Expand, so for instance $1 represents the text of the first submatch. -func (re *Regexp) ReplaceAll(src, repl []byte) []byte { - n := 2 - if bytes.IndexByte(repl, '$') >= 0 { - n = 2 * (re.numSubexp + 1) - } - srepl := "" - b := re.replaceAll(src, "", n, func(dst []byte, match []int) []byte { - if len(srepl) != len(repl) { - srepl = string(repl) - } - return re.expand(dst, srepl, src, "", match) - }) - return b -} - -// ReplaceAllLiteral returns a copy of src, replacing matches of the Regexp -// with the replacement bytes repl. The replacement repl is substituted directly, -// without using Expand. -func (re *Regexp) ReplaceAllLiteral(src, repl []byte) []byte { - return re.replaceAll(src, "", 2, func(dst []byte, match []int) []byte { - return append(dst, repl...) - }) -} - -// ReplaceAllFunc returns a copy of src in which all matches of the -// Regexp have been replaced by the return value of function repl applied -// to the matched byte slice. The replacement returned by repl is substituted -// directly, without using Expand. -func (re *Regexp) ReplaceAllFunc(src []byte, repl func([]byte) []byte) []byte { - return re.replaceAll(src, "", 2, func(dst []byte, match []int) []byte { - return append(dst, repl(src[match[0]:match[1]])...) - }) -} - -var specialBytes = []byte(`\.+*?()|[]{}^$`) - -func special(b byte) bool { - return bytes.IndexByte(specialBytes, b) >= 0 -} - -// QuoteMeta returns a string that quotes all regular expression metacharacters -// inside the argument text; the returned string is a regular expression matching -// the literal text. For example, QuoteMeta(`[foo]`) returns `\[foo\]`. -func QuoteMeta(s string) string { - b := make([]byte, 2*len(s)) - - // A byte loop is correct because all metacharacters are ASCII. - j := 0 - for i := 0; i < len(s); i++ { - if special(s[i]) { - b[j] = '\\' - j++ - } - b[j] = s[i] - j++ - } - return string(b[0:j]) -} - -// The number of capture values in the program may correspond -// to fewer capturing expressions than are in the regexp. -// For example, "(a){0}" turns into an empty program, so the -// maximum capture in the program is 0 but we need to return -// an expression for \1. Pad appends -1s to the slice a as needed. -func (re *Regexp) pad(a []int) []int { - if a == nil { - // No match. - return nil - } - n := (1 + re.numSubexp) * 2 - for len(a) < n { - a = append(a, -1) - } - return a -} - -// Find matches in slice b if b is non-nil, otherwise find matches in string s. -func (re *Regexp) allMatches(s string, b []byte, n int, deliver func([]int)) { - var end int - if b == nil { - end = len(s) - } else { - end = len(b) - } - - for pos, i, prevMatchEnd := 0, 0, -1; i < n && pos <= end; { - matches := re.doExecute(nil, b, s, pos, re.prog.NumCap) - if len(matches) == 0 { - break - } - - accept := true - if matches[1] == pos { - // We've found an empty match. - if matches[0] == prevMatchEnd { - // We don't allow an empty match right - // after a previous match, so ignore it. - accept = false - } - var width int - // TODO: use step() - if b == nil { - _, width = utf8.DecodeRuneInString(s[pos:end]) - } else { - _, width = utf8.DecodeRune(b[pos:end]) - } - if width > 0 { - pos += width - } else { - pos = end + 1 - } - } else { - pos = matches[1] - } - prevMatchEnd = matches[1] - - if accept { - deliver(re.pad(matches)) - i++ - } - } -} - -// Find returns a slice holding the text of the leftmost match in b of the regular expression. -// A return value of nil indicates no match. -func (re *Regexp) Find(b []byte) []byte { - a := re.doExecute(nil, b, "", 0, 2) - if a == nil { - return nil - } - return b[a[0]:a[1]] -} - -// FindIndex returns a two-element slice of integers defining the location of -// the leftmost match in b of the regular expression. The match itself is at -// b[loc[0]:loc[1]]. -// A return value of nil indicates no match. -func (re *Regexp) FindIndex(b []byte) (loc []int) { - a := re.doExecute(nil, b, "", 0, 2) - if a == nil { - return nil - } - return a[0:2] -} - -// FindString returns a string holding the text of the leftmost match in s of the regular -// expression. If there is no match, the return value is an empty string, -// but it will also be empty if the regular expression successfully matches -// an empty string. Use FindStringIndex or FindStringSubmatch if it is -// necessary to distinguish these cases. -func (re *Regexp) FindString(s string) string { - a := re.doExecute(nil, nil, s, 0, 2) - if a == nil { - return "" - } - return s[a[0]:a[1]] -} - -// FindStringIndex returns a two-element slice of integers defining the -// location of the leftmost match in s of the regular expression. The match -// itself is at s[loc[0]:loc[1]]. -// A return value of nil indicates no match. -func (re *Regexp) FindStringIndex(s string) (loc []int) { - a := re.doExecute(nil, nil, s, 0, 2) - if a == nil { - return nil - } - return a[0:2] -} - -// FindReaderIndex returns a two-element slice of integers defining the -// location of the leftmost match of the regular expression in text read from -// the RuneReader. The match text was found in the input stream at -// byte offset loc[0] through loc[1]-1. -// A return value of nil indicates no match. -func (re *Regexp) FindReaderIndex(r io.RuneReader) (loc []int) { - a := re.doExecute(r, nil, "", 0, 2) - if a == nil { - return nil - } - return a[0:2] -} - -// FindSubmatch returns a slice of slices holding the text of the leftmost -// match of the regular expression in b and the matches, if any, of its -// subexpressions, as defined by the 'Submatch' descriptions in the package -// comment. -// A return value of nil indicates no match. -func (re *Regexp) FindSubmatch(b []byte) [][]byte { - a := re.doExecute(nil, b, "", 0, re.prog.NumCap) - if a == nil { - return nil - } - ret := make([][]byte, 1+re.numSubexp) - for i := range ret { - if 2*i < len(a) && a[2*i] >= 0 { - ret[i] = b[a[2*i]:a[2*i+1]] - } - } - return ret -} - -// Expand appends template to dst and returns the result; during the -// append, Expand replaces variables in the template with corresponding -// matches drawn from src. The match slice should have been returned by -// FindSubmatchIndex. -// -// In the template, a variable is denoted by a substring of the form -// $name or ${name}, where name is a non-empty sequence of letters, -// digits, and underscores. A purely numeric name like $1 refers to -// the submatch with the corresponding index; other names refer to -// capturing parentheses named with the (?P<name>...) syntax. A -// reference to an out of range or unmatched index or a name that is not -// present in the regular expression is replaced with an empty slice. -// -// In the $name form, name is taken to be as long as possible: $1x is -// equivalent to ${1x}, not ${1}x, and, $10 is equivalent to ${10}, not ${1}0. -// -// To insert a literal $ in the output, use $$ in the template. -func (re *Regexp) Expand(dst []byte, template []byte, src []byte, match []int) []byte { - return re.expand(dst, string(template), src, "", match) -} - -// ExpandString is like Expand but the template and source are strings. -// It appends to and returns a byte slice in order to give the calling -// code control over allocation. -func (re *Regexp) ExpandString(dst []byte, template string, src string, match []int) []byte { - return re.expand(dst, template, nil, src, match) -} - -func (re *Regexp) expand(dst []byte, template string, bsrc []byte, src string, match []int) []byte { - for len(template) > 0 { - i := strings.Index(template, "$") - if i < 0 { - break - } - dst = append(dst, template[:i]...) - template = template[i:] - if len(template) > 1 && template[1] == '$' { - // Treat $$ as $. - dst = append(dst, '$') - template = template[2:] - continue - } - name, num, rest, ok := extract(template) - if !ok { - // Malformed; treat $ as raw text. - dst = append(dst, '$') - template = template[1:] - continue - } - template = rest - if num >= 0 { - if 2*num+1 < len(match) && match[2*num] >= 0 { - if bsrc != nil { - dst = append(dst, bsrc[match[2*num]:match[2*num+1]]...) - } else { - dst = append(dst, src[match[2*num]:match[2*num+1]]...) - } - } - } else { - for i, namei := range re.subexpNames { - if name == namei && 2*i+1 < len(match) && match[2*i] >= 0 { - if bsrc != nil { - dst = append(dst, bsrc[match[2*i]:match[2*i+1]]...) - } else { - dst = append(dst, src[match[2*i]:match[2*i+1]]...) - } - break - } - } - } - } - dst = append(dst, template...) - return dst -} - -// extract returns the name from a leading "$name" or "${name}" in str. -// If it is a number, extract returns num set to that number; otherwise num = -1. -func extract(str string) (name string, num int, rest string, ok bool) { - if len(str) < 2 || str[0] != '$' { - return - } - brace := false - if str[1] == '{' { - brace = true - str = str[2:] - } else { - str = str[1:] - } - i := 0 - for i < len(str) { - rune, size := utf8.DecodeRuneInString(str[i:]) - if !unicode.IsLetter(rune) && !unicode.IsDigit(rune) && rune != '_' { - break - } - i += size - } - if i == 0 { - // empty name is not okay - return - } - name = str[:i] - if brace { - if i >= len(str) || str[i] != '}' { - // missing closing brace - return - } - i++ - } - - // Parse number. - num = 0 - for i := 0; i < len(name); i++ { - if name[i] < '0' || '9' < name[i] || num >= 1e8 { - num = -1 - break - } - num = num*10 + int(name[i]) - '0' - } - // Disallow leading zeros. - if name[0] == '0' && len(name) > 1 { - num = -1 - } - - rest = str[i:] - ok = true - return -} - -// FindSubmatchIndex returns a slice holding the index pairs identifying the -// leftmost match of the regular expression in b and the matches, if any, of -// its subexpressions, as defined by the 'Submatch' and 'Index' descriptions -// in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindSubmatchIndex(b []byte) []int { - return re.pad(re.doExecute(nil, b, "", 0, re.prog.NumCap)) -} - -// FindStringSubmatch returns a slice of strings holding the text of the -// leftmost match of the regular expression in s and the matches, if any, of -// its subexpressions, as defined by the 'Submatch' description in the -// package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindStringSubmatch(s string) []string { - a := re.doExecute(nil, nil, s, 0, re.prog.NumCap) - if a == nil { - return nil - } - ret := make([]string, 1+re.numSubexp) - for i := range ret { - if 2*i < len(a) && a[2*i] >= 0 { - ret[i] = s[a[2*i]:a[2*i+1]] - } - } - return ret -} - -// FindStringSubmatchIndex returns a slice holding the index pairs -// identifying the leftmost match of the regular expression in s and the -// matches, if any, of its subexpressions, as defined by the 'Submatch' and -// 'Index' descriptions in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindStringSubmatchIndex(s string) []int { - return re.pad(re.doExecute(nil, nil, s, 0, re.prog.NumCap)) -} - -// FindReaderSubmatchIndex returns a slice holding the index pairs -// identifying the leftmost match of the regular expression of text read by -// the RuneReader, and the matches, if any, of its subexpressions, as defined -// by the 'Submatch' and 'Index' descriptions in the package comment. A -// return value of nil indicates no match. -func (re *Regexp) FindReaderSubmatchIndex(r io.RuneReader) []int { - return re.pad(re.doExecute(r, nil, "", 0, re.prog.NumCap)) -} - -const startSize = 10 // The size at which to start a slice in the 'All' routines. - -// FindAll is the 'All' version of Find; it returns a slice of all successive -// matches of the expression, as defined by the 'All' description in the -// package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAll(b []byte, n int) [][]byte { - if n < 0 { - n = len(b) + 1 - } - result := make([][]byte, 0, startSize) - re.allMatches("", b, n, func(match []int) { - result = append(result, b[match[0]:match[1]]) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllIndex is the 'All' version of FindIndex; it returns a slice of all -// successive matches of the expression, as defined by the 'All' description -// in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllIndex(b []byte, n int) [][]int { - if n < 0 { - n = len(b) + 1 - } - result := make([][]int, 0, startSize) - re.allMatches("", b, n, func(match []int) { - result = append(result, match[0:2]) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllString is the 'All' version of FindString; it returns a slice of all -// successive matches of the expression, as defined by the 'All' description -// in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllString(s string, n int) []string { - if n < 0 { - n = len(s) + 1 - } - result := make([]string, 0, startSize) - re.allMatches(s, nil, n, func(match []int) { - result = append(result, s[match[0]:match[1]]) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllStringIndex is the 'All' version of FindStringIndex; it returns a -// slice of all successive matches of the expression, as defined by the 'All' -// description in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllStringIndex(s string, n int) [][]int { - if n < 0 { - n = len(s) + 1 - } - result := make([][]int, 0, startSize) - re.allMatches(s, nil, n, func(match []int) { - result = append(result, match[0:2]) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllSubmatch is the 'All' version of FindSubmatch; it returns a slice -// of all successive matches of the expression, as defined by the 'All' -// description in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllSubmatch(b []byte, n int) [][][]byte { - if n < 0 { - n = len(b) + 1 - } - result := make([][][]byte, 0, startSize) - re.allMatches("", b, n, func(match []int) { - slice := make([][]byte, len(match)/2) - for j := range slice { - if match[2*j] >= 0 { - slice[j] = b[match[2*j]:match[2*j+1]] - } - } - result = append(result, slice) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllSubmatchIndex is the 'All' version of FindSubmatchIndex; it returns -// a slice of all successive matches of the expression, as defined by the -// 'All' description in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllSubmatchIndex(b []byte, n int) [][]int { - if n < 0 { - n = len(b) + 1 - } - result := make([][]int, 0, startSize) - re.allMatches("", b, n, func(match []int) { - result = append(result, match) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllStringSubmatch is the 'All' version of FindStringSubmatch; it -// returns a slice of all successive matches of the expression, as defined by -// the 'All' description in the package comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllStringSubmatch(s string, n int) [][]string { - if n < 0 { - n = len(s) + 1 - } - result := make([][]string, 0, startSize) - re.allMatches(s, nil, n, func(match []int) { - slice := make([]string, len(match)/2) - for j := range slice { - if match[2*j] >= 0 { - slice[j] = s[match[2*j]:match[2*j+1]] - } - } - result = append(result, slice) - }) - if len(result) == 0 { - return nil - } - return result -} - -// FindAllStringSubmatchIndex is the 'All' version of -// FindStringSubmatchIndex; it returns a slice of all successive matches of -// the expression, as defined by the 'All' description in the package -// comment. -// A return value of nil indicates no match. -func (re *Regexp) FindAllStringSubmatchIndex(s string, n int) [][]int { - if n < 0 { - n = len(s) + 1 - } - result := make([][]int, 0, startSize) - re.allMatches(s, nil, n, func(match []int) { - result = append(result, match) - }) - if len(result) == 0 { - return nil - } - return result -} - -// Split slices s into substrings separated by the expression and returns a slice of -// the substrings between those expression matches. -// -// The slice returned by this method consists of all the substrings of s -// not contained in the slice returned by FindAllString. When called on an expression -// that contains no metacharacters, it is equivalent to strings.SplitN. -// -// Example: -// s := regexp.MustCompile("a*").Split("abaabaccadaaae", 5) -// // s: ["", "b", "b", "c", "cadaaae"] -// -// The count determines the number of substrings to return: -// n > 0: at most n substrings; the last substring will be the unsplit remainder. -// n == 0: the result is nil (zero substrings) -// n < 0: all substrings -func (re *Regexp) Split(s string, n int) []string { - - if n == 0 { - return nil - } - - if len(re.expr) > 0 && len(s) == 0 { - return []string{""} - } - - matches := re.FindAllStringIndex(s, n) - strings := make([]string, 0, len(matches)) - - beg := 0 - end := 0 - for _, match := range matches { - if n > 0 && len(strings) >= n-1 { - break - } - - end = match[0] - if match[1] != 0 { - strings = append(strings, s[beg:end]) - } - beg = match[1] - } - - if end != len(s) { - strings = append(strings, s[beg:]) - } - - return strings -} |