Returns the offset (in bytes) of the beginning of the specified match.
When non-negative integer argument n is given, returns the offset of the beginning of the nth match:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.bytebegin(0) # => 1 m[3] # => "113" m.bytebegin(3) # => 3 m = /(т)(е)(с)/.match('тест') # => #<MatchData "тес" 1:"т" 2:"е" 3:"с"> m[0] # => "тес" m.bytebegin(0) # => 0 m[3] # => "с" m.bytebegin(3) # => 4
When string or symbol argument name is given, returns the offset of the beginning for the named match:
m = /(?<foo>.)(.)(?<bar>.)/.match("hoge") # => #<MatchData "hog" foo:"h" bar:"g"> m[:foo] # => "h" m.bytebegin('foo') # => 0 m[:bar] # => "g" m.bytebegin(:bar) # => 2
Related: MatchData#byteend, MatchData#byteoffset.
Returns the offset (in characters) of the beginning of the specified match.
When non-negative integer argument n is given, returns the offset of the beginning of the nth match:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.begin(0) # => 1 m[3] # => "113" m.begin(3) # => 3 m = /(т)(е)(с)/.match('тест') # => #<MatchData "тес" 1:"т" 2:"е" 3:"с"> m[0] # => "тес" m.begin(0) # => 0 m[3] # => "с" m.begin(3) # => 2
When string or symbol argument name is given, returns the offset of the beginning for the named match:
m = /(?<foo>.)(.)(?<bar>.)/.match("hoge") # => #<MatchData "hog" foo:"h" bar:"g"> m[:foo] # => "h" m.begin('foo') # => 0 m[:bar] # => "g" m.begin(:bar) # => 2
Related: MatchData#end, MatchData#offset, MatchData#byteoffset.
Returns a string representation of self:
m = /.$/.match("foo") # => #<MatchData "o"> m.inspect # => "#<MatchData \"o\">" m = /(.)(.)(.)/.match("foo") # => #<MatchData "foo" 1:"f" 2:"o" 3:"o"> m.inspect # => "#<MatchData \"foo\" 1:\"f\" 2:\"o\ m = /(.)(.)?(.)/.match("fo") # => #<MatchData "fo" 1:"f" 2:nil 3:"o"> m.inspect # => "#<MatchData \"fo\" 1:\"f\" 2:nil 3:\"o\">"
Related: MatchData#to_s.
Increases left margin after newline with indent for line breaks added in the block.
Opens a transaction block for the store. See Transactions.
With argument read_only as false, the block may both read from and write to the store.
With argument read_only as true, the block may not include calls to transaction, []=, or delete.
Raises an exception if called within a transaction block.
Unlinks (deletes) the file from the filesystem. One should always unlink the file after using it, as is explained in the “Explicit close” good practice section in the Tempfile overview:
file = Tempfile.new('foo') begin # ...do something with file... ensure file.close file.unlink # deletes the temp file end
On POSIX systems it’s possible to unlink a file before closing it. This practice is explained in detail in the Tempfile overview (section “Unlink after creation”); please refer there for more information.
However, unlink-before-close may not be supported on non-POSIX operating systems. Microsoft Windows is the most notable case: unlinking a non-closed file will result in an error, which this method will silently ignore. If you want to practice unlink-before-close whenever possible, then you should write code like this:
file = Tempfile.new('foo') file.unlink # On Windows this silently fails. begin # ... do something with file ... ensure file.close! # Closes the file handle. If the file wasn't unlinked # because #unlink failed, then this method will attempt # to do so again. end
The string representation of false is “false”.
Returns the number of mandatory arguments. If the block is declared to take no arguments, returns 0. If the block is known to take exactly n arguments, returns n. If the block has optional arguments, returns -n-1, where n is the number of mandatory arguments, with the exception for blocks that are not lambdas and have only a finite number of optional arguments; in this latter case, returns n. Keyword arguments will be considered as a single additional argument, that argument being mandatory if any keyword argument is mandatory. A proc with no argument declarations is the same as a block declaring || as its arguments.
proc {}.arity #=> 0 proc { || }.arity #=> 0 proc { |a| }.arity #=> 1 proc { |a, b| }.arity #=> 2 proc { |a, b, c| }.arity #=> 3 proc { |*a| }.arity #=> -1 proc { |a, *b| }.arity #=> -2 proc { |a, *b, c| }.arity #=> -3 proc { |x:, y:, z:0| }.arity #=> 1 proc { |*a, x:, y:0| }.arity #=> -2 proc { |a=0| }.arity #=> 0 lambda { |a=0| }.arity #=> -1 proc { |a=0, b| }.arity #=> 1 lambda { |a=0, b| }.arity #=> -2 proc { |a=0, b=0| }.arity #=> 0 lambda { |a=0, b=0| }.arity #=> -1 proc { |a, b=0| }.arity #=> 1 lambda { |a, b=0| }.arity #=> -2 proc { |(a, b), c=0| }.arity #=> 1 lambda { |(a, b), c=0| }.arity #=> -2 proc { |a, x:0, y:0| }.arity #=> 1 lambda { |a, x:0, y:0| }.arity #=> -2
Returns the unique identifier for this proc, along with an indication of where the proc was defined.
Returns an indication of the number of arguments accepted by a method. Returns a nonnegative integer for methods that take a fixed number of arguments. For Ruby methods that take a variable number of arguments, returns -n-1, where n is the number of required arguments. Keyword arguments will be considered as a single additional argument, that argument being mandatory if any keyword argument is mandatory. For methods written in C, returns -1 if the call takes a variable number of arguments.
class C def one; end def two(a); end def three(*a); end def four(a, b); end def five(a, b, *c); end def six(a, b, *c, &d); end def seven(a, b, x:0); end def eight(x:, y:); end def nine(x:, y:, **z); end def ten(*a, x:, y:); end end c = C.new c.method(:one).arity #=> 0 c.method(:two).arity #=> 1 c.method(:three).arity #=> -1 c.method(:four).arity #=> 2 c.method(:five).arity #=> -3 c.method(:six).arity #=> -3 c.method(:seven).arity #=> -3 c.method(:eight).arity #=> 1 c.method(:nine).arity #=> 1 c.method(:ten).arity #=> -2 "cat".method(:size).arity #=> 0 "cat".method(:replace).arity #=> 1 "cat".method(:squeeze).arity #=> -1 "cat".method(:count).arity #=> -1
Returns a human-readable description of the underlying method.
"cat".method(:count).inspect #=> "#<Method: String#count(*)>" (1..3).method(:map).inspect #=> "#<Method: Range(Enumerable)#map()>"
In the latter case, the method description includes the “owner” of the original method (Enumerable module, which is included into Range).
inspect also provides, when possible, method argument names (call sequence) and source location.
require 'net/http' Net::HTTP.method(:get).inspect #=> "#<Method: Net::HTTP.get(uri_or_host, path=..., port=...) <skip>/lib/ruby/2.7.0/net/http.rb:457>"
... in argument definition means argument is optional (has some default value).
For methods defined in C (language core and extensions), location and argument names can’t be extracted, and only generic information is provided in form of * (any number of arguments) or _ (some positional argument).
"cat".method(:count).inspect #=> "#<Method: String#count(*)>" "cat".method(:+).inspect #=> "#<Method: String#+(_)>""
Dissociates meth from its current receiver. The resulting UnboundMethod can subsequently be bound to a new object of the same class (see UnboundMethod).
Returns an indication of the number of arguments accepted by a method. Returns a nonnegative integer for methods that take a fixed number of arguments. For Ruby methods that take a variable number of arguments, returns -n-1, where n is the number of required arguments. Keyword arguments will be considered as a single additional argument, that argument being mandatory if any keyword argument is mandatory. For methods written in C, returns -1 if the call takes a variable number of arguments.
class C def one; end def two(a); end def three(*a); end def four(a, b); end def five(a, b, *c); end def six(a, b, *c, &d); end def seven(a, b, x:0); end def eight(x:, y:); end def nine(x:, y:, **z); end def ten(*a, x:, y:); end end c = C.new c.method(:one).arity #=> 0 c.method(:two).arity #=> 1 c.method(:three).arity #=> -1 c.method(:four).arity #=> 2 c.method(:five).arity #=> -3 c.method(:six).arity #=> -3 c.method(:seven).arity #=> -3 c.method(:eight).arity #=> 1 c.method(:nine).arity #=> 1 c.method(:ten).arity #=> -2 "cat".method(:size).arity #=> 0 "cat".method(:replace).arity #=> 1 "cat".method(:squeeze).arity #=> -1 "cat".method(:count).arity #=> -1
Returns a human-readable description of the underlying method.
"cat".method(:count).inspect #=> "#<Method: String#count(*)>" (1..3).method(:map).inspect #=> "#<Method: Range(Enumerable)#map()>"
In the latter case, the method description includes the “owner” of the original method (Enumerable module, which is included into Range).
inspect also provides, when possible, method argument names (call sequence) and source location.
require 'net/http' Net::HTTP.method(:get).inspect #=> "#<Method: Net::HTTP.get(uri_or_host, path=..., port=...) <skip>/lib/ruby/2.7.0/net/http.rb:457>"
... in argument definition means argument is optional (has some default value).
For methods defined in C (language core and extensions), location and argument names can’t be extracted, and only generic information is provided in form of * (any number of arguments) or _ (some positional argument).
"cat".method(:count).inspect #=> "#<Method: String#count(*)>" "cat".method(:+).inspect #=> "#<Method: String#+(_)>""
Bind umeth to obj. If Klass was the class from which umeth was obtained, obj.kind_of?(Klass) must be true.
class A def test puts "In test, class = #{self.class}" end end class B < A end class C < B end um = B.instance_method(:test) bm = um.bind(C.new) bm.call bm = um.bind(B.new) bm.call bm = um.bind(A.new) bm.call
produces:
In test, class = C In test, class = B prog.rb:16:in `bind': bind argument must be an instance of B (TypeError) from prog.rb:16
returns main ractor
return true if the current ractor is main ractor
Returns an array of all existing Thread objects that belong to this group.
ThreadGroup::Default.list #=> [#<Thread:0x401bdf4c run>]
Basically the same as ::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass’s initialize method.
Returns the main thread.
Stops execution of the current thread, putting it into a “sleep” state, and schedules execution of another thread.
a = Thread.new { print "a"; Thread.stop; print "c" } sleep 0.1 while a.status!='sleep' print "b" a.run a.join #=> "abc"
Returns an array of Thread objects for all threads that are either runnable or stopped.
Thread.new { sleep(200) } Thread.new { 1000000.times {|i| i*i } } Thread.new { Thread.stop } Thread.list.each {|t| p t}
This will produce:
#<Thread:0x401b3e84 sleep> #<Thread:0x401b3f38 run> #<Thread:0x401b3fb0 sleep> #<Thread:0x401bdf4c run>