Returns a MatchData
object (or nil
) based on self
and the given pattern
.
Note: also updates Global Variables at Regexp
.
Computes regexp
by converting pattern
(if not already a Regexp
).
regexp = Regexp.new(pattern)
Computes matchdata
, which will be either a MatchData
object or nil
(see Regexp#match
):
matchdata = <tt>regexp.match(self)
With no block given, returns the computed matchdata
:
'foo'.match('f') # => #<MatchData "f"> 'foo'.match('o') # => #<MatchData "o"> 'foo'.match('x') # => nil
If Integer
argument offset
is given, the search begins at index offset
:
'foo'.match('f', 1) # => nil 'foo'.match('o', 1) # => #<MatchData "o">
With a block given, calls the block with the computed matchdata
and returns the block’s return value:
'foo'.match(/o/) {|matchdata| matchdata } # => #<MatchData "o"> 'foo'.match(/x/) {|matchdata| matchdata } # => nil 'foo'.match(/f/, 1) {|matchdata| matchdata } # => nil
With no block given, returns the MatchData
object that describes the match, if any, or nil
if none; the search begins at the given character offset
in string
:
/abra/.match('abracadabra') # => #<MatchData "abra"> /abra/.match('abracadabra', 4) # => #<MatchData "abra"> /abra/.match('abracadabra', 8) # => nil /abra/.match('abracadabra', 800) # => nil string = "\u{5d0 5d1 5e8 5d0}cadabra" /abra/.match(string, 7) #=> #<MatchData "abra"> /abra/.match(string, 8) #=> nil /abra/.match(string.b, 8) #=> #<MatchData "abra">
With a block given, calls the block if and only if a match is found; returns the block’s value:
/abra/.match('abracadabra') {|matchdata| p matchdata } # => #<MatchData "abra"> /abra/.match('abracadabra', 4) {|matchdata| p matchdata } # => #<MatchData "abra"> /abra/.match('abracadabra', 8) {|matchdata| p matchdata } # => nil /abra/.match('abracadabra', 8) {|marchdata| fail 'Cannot happen' } # => nil
Output (from the first two blocks above):
#<MatchData "abra"> #<MatchData "abra"> /(.)(.)(.)/.match("abc")[2] # => "b" /(.)(.)/.match("abc", 1)[2] # => "c"
Equivalent to self.to_s.match
, including possible updates to global variables; see String#match
.
Returns the matched substring corresponding to the given argument.
When non-negative argument n
is given, returns the matched substring for the n
th match:
m = /(.)(.)(\d+)(\d)(\w)?/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8" 5:nil> m.match(0) # => "HX1138" m.match(4) # => "8" m.match(5) # => nil
When string or symbol argument name
is given, returns the matched substring for the given name:
m = /(?<foo>.)(.)(?<bar>.+)/.match("hoge") # => #<MatchData "hoge" foo:"h" bar:"ge"> m.match('foo') # => "h" m.match(:bar) # => "ge"
With no argument, returns the value of $!
, which is the result of the most recent pattern match (see Regexp global variables):
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match # => #<MatchData "cat" 1:"a"> /a/ =~ 'foo' # => nil Regexp.last_match # => nil
With non-negative integer argument n
, returns the _n_th field in the matchdata, if any, or nil if none:
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match(0) # => "cat" Regexp.last_match(1) # => "a" Regexp.last_match(2) # => nil
With negative integer argument n
, counts backwards from the last field:
Regexp.last_match(-1) # => "a"
With string or symbol argument name
, returns the string value for the named capture, if any:
/(?<lhs>\w+)\s*=\s*(?<rhs>\w+)/ =~ 'var = val' Regexp.last_match # => #<MatchData "var = val" lhs:"var"rhs:"val"> Regexp.last_match(:lhs) # => "var" Regexp.last_match('rhs') # => "val" Regexp.last_match('foo') # Raises IndexError.
Returns the pre-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the post-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the length (in characters) of the matched substring corresponding to the given argument.
When non-negative argument n
is given, returns the length of the matched substring for the n
th match:
m = /(.)(.)(\d+)(\d)(\w)?/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8" 5:nil> m.match_length(0) # => 6 m.match_length(4) # => 1 m.match_length(5) # => nil
When string or symbol argument name
is given, returns the length of the matched substring for the named match:
m = /(?<foo>.)(.)(?<bar>.+)/.match("hoge") # => #<MatchData "hoge" foo:"h" bar:"ge"> m.match_length('foo') # => 1 m.match_length(:bar) # => 2
Returns the substring of the target string from its beginning up to the first match in self
(that is, self[0]
); equivalent to regexp global variable $`
:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.pre_match # => "T"
Related: MatchData#post_match
.
Returns the substring of the target string from the end of the first match in self
(that is, self[0]
) to the end of the string; equivalent to regexp global variable $'
:
m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.post_match # => ": The Movie"\
Related: MatchData.pre_match
.
Completion
for hash key.
Indicate if this NameTuple
matches the current platform.
Compile a MatchPredicateNode
node
Dispatch enter and leave events for MatchPredicateNode
nodes and continue walking the tree.
Inspect a MatchPredicateNode
node.
@return [Array] specs of default gems that are ‘==` to the given `spec`.
Compile a CaseMatchNode
node
Compile a MatchRequiredNode
node