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class Regexp
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Parent:
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Object
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Version:
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1.6
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Index:
compile
escape
last_match
new
quote
==
===
=~
~
casefold?
kcode
match
source
A
Regexp holds a regular expression, used to match a pattern against
strings. Regexps are created using the
/.../ and
%r{...}
literals, and by the
Regexp.new
constructor.
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EXTENDED
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Ignore spaces and newlines in regexp. |
IGNORECASE
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Matches are case insensitive. |
MULTILINE
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Newlines treated as any other character. |
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class methods
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compile
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Regexp.compile( pattern
[, options [
lang
]
] )
-> aRegexp
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Synonym for Regexp.new.
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escape
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Regexp.escape( aString )
-> aNewString
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Escapes any characters that would have special meaning in a
regular expression. For any string,
Regexp.escape(str)=~str
will be true.
Regexp.escape('\\*?{}.')
|
» |
\\\\\*\?\{\}\.
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last_match
|
Regexp.last_match
-> aMatchData
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Returns the MatchData object generated by the last
successful pattern match. Equivalent to reading the global
variable $~. MatchData is described
on page 336.
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new
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Regexp.new( pattern
[, options [
lang
]
] )
-> aRegexp
|
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Constructs a new regular expression from pattern, which can
be either a String or a Regexp (in which case that
regexp's options are not propagated). If options is
a Fixnum, it should be one or more of the constants
Regexp::EXTENDED, Regexp::IGNORECASE, and
Regexp::POSIXLINE, or-ed together.
Otherwise, if options is not
nil, the regexp will be case insensitive. The lang
parameter enables multibyte support for the regexp: `n', `N' = none,
`e', `E' = EUC, `s', `S' = SJIS, `u',
`U' = UTF-8.
r1 = Regexp.new('^a-z+:\\s+\w+')
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» |
/^a-z+:\s+\w+/
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r2 = Regexp.new(r1, true)
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» |
/^a-z+:\s+\w+/i
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r3 = Regexp.new(r2, Regexp::EXTENDED)
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» |
/^a-z+:\s+\w+/x
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|
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quote
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Regexp.quote( aString )
-> aNewString
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Synonym for Regexp.escape.
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instance methods
|
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==
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rxp == aRegexp
-> true or false
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Equality---Two regexps are equal if their patterns are identical, they have
the same character set code, and their casefold? values are
the same.
/abc/ == /abc/x
|
» |
false
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/abc/ == /abc/i
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» |
false
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/abc/u == /abc/n
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» |
false
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===
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rxp === aString -> true or false
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Case Equality---Synonym for
Regexp#=~
used in case statements.
a = "HELLO"
case a
when /^a-z*$/; print "Lower case\n"
when /^A-Z*$/; print "Upper case\n"
else; print "Mixed case\n"
end
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produces:
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=~
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rxp =~ aString
-> anInteger or nil
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Match---Matches rxp against aString, returning the offset
of the start of the match or nil if the match failed.
/SIT/ =~ "insensitive"
|
» |
nil
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/SIT/i =~ "insensitive"
|
» |
5
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~
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~ rxp
-> anInteger or nil
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Match---Matches rxp against the contents of $_. Equivalent to
rxp =~ $_.
$_ = "input data"
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~ /at/
|
» |
7
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casefold?
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rxp.casefold? -> true or false
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Returns the value of the case-insensitive flag.
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|
kcode
|
rxp.kcode -> aString
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Returns the character set code for the regexp.
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match
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rxp.match(aString)
-> aMatchData or nil
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Returns a MatchData object (see page 336)
describing the match, or nil if there was no match. This
is equivalent to retrieving the value of the special variable
$~ following a normal match.
/(.)(.)(.)/.match("abc")[2]
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» |
"b"
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source
|
rxp.source -> aString
|
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Returns the original string of the pattern.
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Extracted from the book "Programming Ruby -
The Pragmatic Programmer's Guide"
Copyright
©
2001 by Addison Wesley Longman, Inc. This material may
be distributed only subject to the terms and conditions set forth in
the Open Publication License, v1.0 or later (the latest version is
presently available at
http://www.opencontent.org/openpub/)).
Distribution of substantively modified versions of this document is
prohibited without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard
(paper) book form is prohibited unless prior permission is obtained
from the copyright holder.
