Thanks for the tip! 
Still, sprinkling that option around might
cause more confusion than assigning the regexp to a constant and using
that reference instead. Someone reading your code later may overlook
the dangling "o" on a complex regexp and be left wondering why the
interpolation isn't happening like they expect.
I guess it really depends on the scope of your task though.
-Jeremy
···
On 02/02/2012 09:47 PM, Josh Cheek wrote:
On Thu, Feb 2, 2012 at 8:57 PM, Jeremy Bopp <jeremy@bopp.net> wrote:
Try a similar change to the other looping variations that have been
discussed and see if and how much they may improve. For me I didn't
really see any difference between using re as above or using the simple
regexp directly; however, the code was almost an order of magnitude
slower when I replaced the comparison as follows:s =~ / test#{} /
It seems that Ruby is smart enough to see that the simple regexp will
never need to be re-evaluated. The regexp used above must force that
optimization off because #{} while constantly evaluated to the empty
string is technically dynamic, thus the regexp needs to be re-evaluated
in every iteration of the loop.The o flag tells Ruby to only interpolate the first time, and then cache
the regexs =~ / test#{} /o
But I have to confess: I'm REALLY tempted to, in some