Returns a clone of this method.
class A def foo return "bar" end end m = A.new.method(:foo) m.call # => "bar" n = m.clone.call # => "bar"
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 the bound receiver of the method object.
(1..3).method(:map).receiver # => 1..3
Returns the class or module on which this method is defined. In other words,
meth.owner.instance_methods(false).include?(meth.name) # => true
holds as long as the method is not removed/undefined/replaced, (with private_instance_methods instead of instance_methods if the method is private).
See also Method#receiver.
(1..3).method(:map).owner #=> Enumerable
Returns a clone of this method.
class A def foo return "bar" end end m = A.new.method(:foo) m.call # => "bar" n = m.clone.call # => "bar"
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 the class or module on which this method is defined. In other words,
meth.owner.instance_methods(false).include?(meth.name) # => true
holds as long as the method is not removed/undefined/replaced, (with private_instance_methods instead of instance_methods if the method is private).
See also Method#receiver.
(1..3).method(:map).owner #=> Enumerable
Wait for any ractor to have something in its outgoing port, read from this ractor, and then return that ractor and the object received.
r1 = Ractor.new {Ractor.yield 'from 1'} r2 = Ractor.new {Ractor.yield 'from 2'} r, obj = Ractor.select(r1, r2) puts "received #{obj.inspect} from #{r.inspect}" # Prints: received "from 1" from #<Ractor:#2 test.rb:1 running> # But could just as well print "from r2" here, either prints could be first.
If one of the given ractors is the current ractor, and it is selected, r will contain the :receive symbol instead of the ractor object.
r1 = Ractor.new(Ractor.current) do |main| main.send 'to main' Ractor.yield 'from 1' end r2 = Ractor.new do Ractor.yield 'from 2' end r, obj = Ractor.select(r1, r2, Ractor.current) puts "received #{obj.inspect} from #{r.inspect}" # Could print: received "to main" from :receive
If yield_value is provided, that value may be yielded if another ractor is calling take. In this case, the pair [:yield, nil] is returned:
r1 = Ractor.new(Ractor.current) do |main| puts "Received from main: #{main.take}" end puts "Trying to select" r, obj = Ractor.select(r1, Ractor.current, yield_value: 123) wait puts "Received #{obj.inspect} from #{r.inspect}"
This will print:
Trying to select Received from main: 123 Received nil from :yield
move boolean flag defines whether yielded value will be copied (default) or moved.
Send a message to a Ractor’s incoming queue to be accepted by Ractor.receive.
r = Ractor.new do value = Ractor.receive puts "Received #{value}" end r.send 'message' # Prints: "Received: message"
The method is non-blocking (will return immediately even if the ractor is not ready to receive anything):
r = Ractor.new {sleep(5)} r.send('test') puts "Sent successfully" # Prints: "Sent successfully" immediately
An attempt to send to a ractor which already finished its execution will raise Ractor::ClosedError.
r = Ractor.new {} r.take p r # "#<Ractor:#6 (irb):23 terminated>" r.send('test') # Ractor::ClosedError (The incoming-port is already closed)
If close_incoming was called on the ractor, the method also raises Ractor::ClosedError.
r = Ractor.new do sleep(500) receive end r.close_incoming r.send('test') # Ractor::ClosedError (The incoming-port is already closed) # The error is raised immediately, not when the ractor tries to receive
If the obj is unshareable, by default it will be copied into the receiving ractor by deep cloning. If move: true is passed, the object is moved into the receiving ractor and becomes inaccessible to the sender.
r = Ractor.new {puts "Received: #{receive}"} msg = 'message' r.send(msg, move: true) r.take p msg
This prints:
Received: message in `p': undefined method `inspect' for #<Ractor::MovedObject:0x000055c99b9b69b8>
All references to the object and its parts will become invalid to the sender.
r = Ractor.new {puts "Received: #{receive}"} s = 'message' ary = [s] copy = ary.dup r.send(ary, move: true) s.inspect # Ractor::MovedError (can not send any methods to a moved object) ary.class # Ractor::MovedError (can not send any methods to a moved object) copy.class # => Array, it is different object copy[0].inspect # Ractor::MovedError (can not send any methods to a moved object) # ...but its item was still a reference to `s`, which was moved
If the object is shareable, move: true has no effect on it:
r = Ractor.new {puts "Received: #{receive}"} s = 'message'.freeze r.send(s, move: true) s.inspect #=> "message", still available
Checks if the object is shareable by ractors.
Ractor.shareable?(1) #=> true -- numbers and other immutable basic values are frozen Ractor.shareable?('foo') #=> false, unless the string is frozen due to # frozen_string_literal: true Ractor.shareable?('foo'.freeze) #=> true
See also the “Shareable and unshareable objects” section in the Ractor class docs.
Returns the seed value used to initialize the generator. This may be used to initialize another generator with the same state at a later time, causing it to produce the same sequence of numbers.
prng1 = Random.new(1234) prng1.seed #=> 1234 prng1.rand(100) #=> 47 prng2 = Random.new(prng1.seed) prng2.rand(100) #=> 47
Returns the seed value used to initialize the Ruby system PRNG. This may be used to initialize another generator with the same state at a later time, causing it to produce the same sequence of numbers.
Random.seed #=> 1234 prng1 = Random.new(Random.seed) prng1.seed #=> 1234 prng1.rand(100) #=> 47 Random.seed #=> 1234 Random.rand(100) #=> 47
Prevents threads from being added to or removed from the receiving ThreadGroup.
New threads can still be started in an enclosed ThreadGroup.
ThreadGroup::Default.enclose #=> #<ThreadGroup:0x4029d914> thr = Thread.new { Thread.stop } #=> #<Thread:0x402a7210 sleep> tg = ThreadGroup.new #=> #<ThreadGroup:0x402752d4> tg.add thr #=> ThreadError: can't move from the enclosed thread group
Returns true if the thgrp is enclosed. See also ThreadGroup#enclose.
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.
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"
Give the thread scheduler a hint to pass execution to another thread. A running thread may or may not switch, it depends on OS and processor.
Raises an exception from the given thread. The caller does not have to be thr. See Kernel#raise for more information.
Thread.abort_on_exception = true a = Thread.new { sleep(200) } a.raise("Gotcha")
This will produce:
prog.rb:3: Gotcha (RuntimeError) from prog.rb:2:in `initialize' from prog.rb:2:in `new' from prog.rb:2
Terminates thr and schedules another thread to be run, returning the terminated Thread. If this is the main thread, or the last thread, exits the process.
Returns the priority of thr. Default is inherited from the current thread which creating the new thread, or zero for the initial main thread; higher-priority thread will run more frequently than lower-priority threads (but lower-priority threads can also run).
This is just hint for Ruby thread scheduler. It may be ignored on some platform.
Thread.current.priority #=> 0
Sets the priority of thr to integer. Higher-priority threads will run more frequently than lower-priority threads (but lower-priority threads can also run).
This is just hint for Ruby thread scheduler. It may be ignored on some platform.
count1 = count2 = 0 a = Thread.new do loop { count1 += 1 } end a.priority = -1 b = Thread.new do loop { count2 += 1 } end b.priority = -2 sleep 1 #=> 1 count1 #=> 622504 count2 #=> 5832
Returns true if thr is dead or sleeping.
a = Thread.new { Thread.stop } b = Thread.current a.stop? #=> true b.stop? #=> false
Returns the path of the file being executed.
Returns the trace object during the event.
Similar to the following, but it returns the correct object (the method receiver) for :c_call and :c_return events:
trace.binding.eval('self')
Raises an exception; see Exceptions.
Argument exception sets the class of the new exception; it should be class Exception or one of its subclasses (most commonly, RuntimeError or StandardError), or an instance of one of those classes:
begin raise(StandardError) rescue => x p x.class end # => StandardError
Argument message sets the stored message in the new exception, which may be retrieved by method Exception#message; the message must be a string-convertible object or nil:
begin raise(StandardError, 'Boom') rescue => x p x.message end # => "Boom"
If argument message is not given, the message is the exception class name.
See Exceptions.
Argument backtrace might be used to modify the backtrace of the new exception, as reported by Exception#backtrace and Exception#backtrace_locations; the backtrace must be an array of Thread::Backtrace::Location, an array of strings, a single string, or nil.
Using the array of Thread::Backtrace::Location instances is the most consistent option and should be preferred when possible. The necessary value might be obtained from caller_locations, or copied from Exception#backtrace_locations of another error:
begin do_some_work() rescue ZeroDivisionError => ex raise(LogicalError, "You have an error in your math", ex.backtrace_locations) end
The ways, both Exception#backtrace and Exception#backtrace_locations of the raised error are set to the same backtrace.
When the desired stack of locations is not available and should be constructed from scratch, an array of strings or a singular string can be used. In this case, only Exception#backtrace is set:
begin raise(StandardError, 'Boom', %w[dsl.rb:3 framework.rb:1]) rescue => ex p ex.backtrace # => ["dsl.rb:3", "framework.rb:1"] p ex.backtrace_locations # => nil end
If argument backtrace is not given, the backtrace is set according to an array of Thread::Backtrace::Location objects, as derived from the call stack.
See Exceptions.
Keyword argument cause sets the stored cause in the new exception, which may be retrieved by method Exception#cause; the cause must be an exception object (Exception or one of its subclasses), or nil:
begin raise(StandardError, cause: RuntimeError.new) rescue => x p x.cause end # => #<RuntimeError: RuntimeError>
If keyword argument cause is not given, the cause is the value of $!.
See Exceptions.
In the alternate calling sequence, where argument exception not given, raises a new exception of the class given by $!, or of class RuntimeError if $! is nil:
begin raise rescue => x p x end # => RuntimeError
With argument exception not given, argument message and keyword argument cause may be given, but argument backtrace may not be given.