Package regexp
import "regexp"
Package regexp implements a simple regular expression library.
The syntax of the regular expressions accepted is:
regexp:
concatenation { '|' concatenation }
concatenation:
{ closure }
closure:
term [ '*' | '+' | '?' ]
term:
'^'
'$'
'.'
character
'[' [ '^' ] character-ranges ']'
'(' regexp ')'
Package files
regexp.goVariables
Error codes returned by failures to parse an expression.
var (
ErrInternal = os.NewError("internal error")
ErrUnmatchedLpar = os.NewError("unmatched '('")
ErrUnmatchedRpar = os.NewError("unmatched ')'")
ErrUnmatchedLbkt = os.NewError("unmatched '['")
ErrUnmatchedRbkt = os.NewError("unmatched ']'")
ErrBadRange = os.NewError("bad range in character class")
ErrExtraneousBackslash = os.NewError("extraneous backslash")
ErrBadClosure = os.NewError("repeated closure (**, ++, etc.)")
ErrBareClosure = os.NewError("closure applies to nothing")
ErrBadBackslash = os.NewError("illegal backslash escape")
)
func Match
func Match(pattern string, b []byte) (matched bool, error os.Error)
Match checks whether a textual regular expression matches a byte slice. More complicated queries need to use Compile and the full Regexp interface.
func MatchString
func MatchString(pattern string, s string) (matched bool, error os.Error)
MatchString checks whether a textual regular expression matches a string. More complicated queries need to use Compile and the full Regexp interface.
func QuoteMeta
func QuoteMeta(s string) string
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 `\[foo\]`.
type Regexp
Regexp is the representation of a compiled regular expression. The public interface is entirely through methods.
type Regexp struct {
// contains unexported fields
}
func Compile
func Compile(str string) (regexp *Regexp, error os.Error)
Compile parses a regular expression and returns, if successful, a Regexp object that can be used to match against text.
func MustCompile
func MustCompile(str string) *Regexp
MustCompile is like Compile but panics if the expression cannot be parsed. It simplifies safe initialization of global variables holding compiled regular expressions.
func (*Regexp) AllMatches
func (re *Regexp) AllMatches(b []byte, n int) [][]byte
AllMatches slices the byte slice b into substrings that are successive matches of the Regexp within b. If n > 0, the function returns at most n matches. Text that does not match the expression will be skipped. Empty matches abutting a preceding match are ignored. The function returns a slice containing the matching substrings.
func (*Regexp) AllMatchesIter
func (re *Regexp) AllMatchesIter(b []byte, n int) <-chan []byte
AllMatchesIter slices the byte slice b into substrings that are successive matches of the Regexp within b. If n > 0, the function returns at most n matches. Text that does not match the expression will be skipped. Empty matches abutting a preceding match are ignored. The function returns a channel that iterates over the matching substrings.
func (*Regexp) AllMatchesString
func (re *Regexp) AllMatchesString(s string, n int) []string
AllMatchesString slices the string s into substrings that are successive matches of the Regexp within s. If n > 0, the function returns at most n matches. Text that does not match the expression will be skipped. Empty matches abutting a preceding match are ignored. The function returns a slice containing the matching substrings.
func (*Regexp) AllMatchesStringIter
func (re *Regexp) AllMatchesStringIter(s string, n int) <-chan string
AllMatchesStringIter slices the string s into substrings that are successive matches of the Regexp within s. If n > 0, the function returns at most n matches. Text that does not match the expression will be skipped. Empty matches abutting a preceding match are ignored. The function returns a channel that iterates over the matching substrings.
func (*Regexp) Execute
func (re *Regexp) Execute(b []byte) (a []int)
Execute matches the Regexp against the byte slice b. The return value is an array of integers, in pairs, identifying the positions of subslices matched by the expression.
b[a[0]:a[1]] is the subslice matched by the entire expression. b[a[2*i]:a[2*i+1]] for i > 0 is the subslice matched by the ith parenthesized subexpression.
A negative value means the subexpression did not match any element of the slice. An empty array means "no match".
func (*Regexp) ExecuteString
func (re *Regexp) ExecuteString(s string) (a []int)
ExecuteString matches the Regexp against the string s. The return value is an array of integers, in pairs, identifying the positions of substrings matched by the expression.
s[a[0]:a[1]] is the substring matched by the entire expression. s[a[2*i]:a[2*i+1]] for i > 0 is the substring matched by the ith parenthesized subexpression.
A negative value means the subexpression did not match any element of the string. An empty array means "no match".
func (*Regexp) Match
func (re *Regexp) Match(b []byte) bool
Match returns whether the Regexp matches the byte slice b. The return value is a boolean: true for match, false for no match.
func (*Regexp) MatchSlices
func (re *Regexp) MatchSlices(b []byte) (a [][]byte)
MatchSlices matches the Regexp against the byte slice b. The return value is an array of subslices matched by the expression.
a[0] is the subslice matched by the entire expression. a[i] for i > 0 is the subslice matched by the ith parenthesized subexpression.
An empty array means “no match”.
func (*Regexp) MatchString
func (re *Regexp) MatchString(s string) bool
MatchString returns whether the Regexp matches the string s. The return value is a boolean: true for match, false for no match.
func (*Regexp) MatchStrings
func (re *Regexp) MatchStrings(s string) (a []string)
MatchStrings matches the Regexp against the string s. The return value is an array of strings matched by the expression.
a[0] is the substring matched by the entire expression. a[i] for i > 0 is the substring matched by the ith parenthesized subexpression.
An empty array means “no match”.
func (*Regexp) NumSubexp
func (re *Regexp) NumSubexp() int
NumSubexp returns the number of parenthesized subexpressions in this Regexp.
func (*Regexp) ReplaceAll
func (re *Regexp) ReplaceAll(src, repl []byte) []byte
ReplaceAll returns a copy of src in which all matches for the Regexp have been replaced by repl. No support is provided for expressions (e.g. \1 or $1) in the replacement text.
func (*Regexp) ReplaceAllString
func (re *Regexp) ReplaceAllString(src, repl string) string
ReplaceAllString returns a copy of src in which all matches for the Regexp have been replaced by repl. No support is provided for expressions (e.g. \1 or $1) in the replacement string.