Why can't I do something like this:
do_once = Proc.new { yield } do_once.call { puts 1 }
irb throws LocalJumpError: no block given (yield)
yield
applies to the block passed to the wrapping method context. In your case, I presume it is whichever method irb
relies upon ( lib/ruby/2.0.0/irb/workspace.rb:86 evaluate
, if caller
is anything to go by).
If you wrap it in a function it'll work, because you change the method context:
def do_stuff
do_once = Proc.new { yield }
do_once.call
end
do_stuff { puts 1 }
Note the absence of block for do_once.call
in the above: yield
applies to the block passed to do_stuff
, rather than to the block passed to do_once
.
Alternatively, declare the block explicitly to avoid the use of yield altogether:
do_once = Proc.new { |&block| block.call }
do_once.call { puts 1 }
You can do:
do_once = Proc.new { |&block| block.call }
do_once.call { puts 1 }
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