[Q] is it impossible to pass block into proc object?

Discussion in 'Ruby' started by makoto kuwata, Apr 22, 2012.

  1. Hi,

    I have a question about proc object and block.

    I tried the following code:

    pr = proc do
    yield "hom"

    pr.call do |arg|
    p arg

    What I expected is:

    $ ruby homhom.rb

    But I got:

    $ ruby homhom.rb
    homhom.rb:2:in `block in <main>': no block given (yield)
    from homhom.rb:5:in `call'
    from homhom.rb:5:in `<main>'
    $ ruby -v
    ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-darwin10.8.0]

    Is it impossible to pass block to proc object?
    makoto kuwata, Apr 22, 2012
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  2. The only way I am aware of ATM is explicit:

    irb(main):003:0> pr = lambda {|bl| bl.call "hom" }
    => #<Proc:0x829cd74@(irb):3 (lambda)>
    irb(main):004:0> pr.call lambda {|x| p x}
    => "hom"

    Kind regards

    Robert Klemme, Apr 22, 2012
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