CODEWITHSUNDEEP
rubylambda
Derick Bailey
Derick Bailey

Reputation: 72868

Ruby: yield block from a block?

Is it possible for a lambda, proc, method or other type of block in ruby, to yield to another block?
something like...

a = lambda {
  puts 'in a'
  yield if block_given?
}

a.call { puts "in a's block" }

this doesn't work... it just produces

in a
=> nil

Is there way to get the block to call a block?

Upvotes: 11

Views: 3970

Answers (2)

jrhicks
jrhicks

Reputation: 14997

You can call the block, which is similar to yielding.

a = lambda {|&block| block.call if block}
a.call {print "hello"}

Note that

a.call

Will not return an error.

Upvotes: 8

ottobar
ottobar

Reputation: 4361

I'm not sure if you can you can do that, but something similar would be:

In Ruby 1.8.6:

a = lambda { |my_proc|
  puts 'in a'
  my_proc.call
}

a.call(lambda { puts "in a's block" })

In Ruby 1.9.1, you can have block parameters

a = lambda { |&block|
  puts 'in a'
  block.call
}

a.call { puts "in a's block" }

Upvotes: 9

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