From: Joel VanderWerf <vjoel@...>
Date: 2007-01-15T05:16:02+09:00
Subject: Re: return_on

Devin Mullins wrote:
> Joel VanderWerf wrote:
>> Gavin Sinclair wrote:
>>> def x
>>>   @cache[:x] ||= begin
>>>     # do stuff
>>>   end
>>> end
>>
>> Or (saving an exception handler setup):
> 
> Does begin...end really have some sort of overhead? I've found that one 
> the nicest looking yet, and I'd hate to dismiss it based on a false 
> perception.

The overhead is smaller than I remembered, pretty negligible apparently:

require 'benchmark'

def meth_with_begin_end
   x = begin 3 end
end

def meth_without_begin_end
   x = 3
end

N = 10000000

Benchmark.bmbm do |b|
   b.report("meth_with_begin_end") do
     N.times {meth_with_begin_end}
   end
   b.report("meth_without_begin_end") do
     N.times {meth_without_begin_end}
   end
end

__END__

Rehearsal ----------------------------------------------------------
meth_with_begin_end      5.648000   0.000000   5.648000 (  5.729000)
meth_without_begin_end   5.458000   0.000000   5.458000 (  5.458000)
------------------------------------------------ total: 11.106000sec

                              user     system      total        real
meth_with_begin_end      5.708000   0.000000   5.708000 (  5.718000)
meth_without_begin_end   5.608000   0.000000   5.608000 (  5.608000)


-- 
        vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407