The cost of explicit returns in ruby

Yesterday Pratik Naik wrote a post on one of his pet hates - explicit returns in ruby. I agree 100% with Pratik, I can’t stand them either.

In one of the comments, Chris Wanstrath posted this microbenchmark showing that using explicit returns incurs a surprising performance hit. It seemed crazy to me, so I thought I’d investigate further, running the benchmark on jruby and ruby 1.9 for comparison.

ruby 1.8.7 (2008-08-11 patchlevel 72)

user     system      total        real
explicit   3.420000   0.020000   3.440000 (  3.478501)
implicit   2.220000   0.000000   2.220000 (  2.236413)

jruby 1.1.6 (ruby 1.8.6 patchlevel 114)

user     system      total        real
explicit   2.611000   0.000000   2.611000 (  2.611001)
implicit   2.541000   0.000000   2.541000 (  2.541385)

ruby 1.9.1p0 (2009-01-30 revision 21907)

user     system      total        real
explicit   1.580000   0.010000   1.590000 (  1.614273)
implicit   1.520000   0.000000   1.520000 (  1.537492)

So neither jruby nor ruby 1.9 incur this penalty.

Is this good news or not? If, like me, you consider explicit returns a code smell, I guess it doesn’t matter either way.