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using object(s) do ... (See related posts)

A little meta-hack that allows one to temporarily assign one or more objects into the scope of a block. My thanks to vinterbleg for optimizing it.

def using (*args)
  yield *args
end


For (a rather half-assed) example:

>> using [10,20,30], 40 do |x,y|
>>   x << y if y.is_a? Fixnum
>>   puts x.to_s
>> end
10203040
=> nil
to ruby metaprogramming by bleeder on Fri Apr 11 10:31:22 -0400 2008

Comments on this post

vinterbleg posts on Apr 13, 2008 at 08:45
Can be rewritten as:

def using(*args)
    yield *args
end


The error checking is done automatically, and the &block argument is unnecessary when using yield.
bleeder posts on Apr 14, 2008 at 10:01
True, error checking is done automatically, but the errors produced are not always very descriptive to the actual problem - that's why I decided to add my own error check.

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