instance method

Kernel#loop

() { () -> void } -> bot

() -> ::Enumerator[nil, bot]

loop { block }

loop → an_enumerator

# File tmp/rubies/ruby-4.0.0/kernel.rb, line 161
def loop
  Primitive.attr! :inline_block
  unless defined?(yield)
    return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, rb_f_loop_size)'
  end

  begin
    while true
      yield
    end
  rescue StopIteration => e
    e.result
  end
end

Repeatedly executes the block.

If no block is given, an enumerator is returned instead.

Example

loop do
  print "Input: "
  line = gets
  # break if q, Q is entered or EOF signal (Ctrl-D on Unix, Ctrl-Z on windows) is sent
  break if !line or line =~ /^q/i
  # ...
end

A StopIteration raised in the block breaks the loop. In this case, loop returns the “result” value stored in the exception.

Example

enum = Enumerator.new { |y|
  y << "one"
  y << "two"
  :ok
}

result = loop {
  puts enum.next
} #=> :ok

See also #local_variables #__method__ #load #open also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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