From: Dave Cantrell <ruby-talk@...>
Date: 2006-02-16T04:03:43+09:00
Subject: Re: Rescuing blocks?

On a lark, I did this, and was shocked at the result. Why the massive 
difference in performance between "begin; end" within a block, and "{ }" 
within a block?

I may do some more tinkering with this later on.

require 'benchmark'

N = 10_000_000

Benchmark.bmbm do |b|
   b.report 'begin' do
     N.times { begin; rescue; end }
   end

   b.report 'begin no rescue' do
     N.times { begin; end }
   end

   b.report 'no begin nested' do
     N.times { { } }
   end

   b.report 'plain' do
     N.times { }
   end
end

Rehearsal ---------------------------------------------------
begin             3.547000   0.000000   3.547000 (  3.656000)
begin no rescue   2.797000   0.000000   2.797000 (  2.860000)
no begin nested  38.062000   0.453000  38.515000 ( 40.593000)
plain             1.735000   0.000000   1.735000 (  1.782000)
----------------------------------------- total: 46.594000sec

                       user     system      total        real
begin             3.516000   0.000000   3.516000 (  3.594000)
begin no rescue   2.750000   0.000000   2.750000 (  2.828000)
no begin nested  36.422000   0.297000  36.719000 ( 38.797000)
plain             1.750000   0.000000   1.750000 (  1.781000)