I'm not sure using or not using def would cause performance differences. It just affects variable scope.
http://mrhaki.blogspot.com/2009/11/groovy-goodness-variable-scope-in.html Erick Nelson Senior Developer HD Supply, FM Cell 858-740-6523 Home 760-930-0461 CONFIDENTIALITY NOTICE: This message is for intended addressee(s) only and may contain information that is confidential, proprietary or exempt from disclosure, and subject to terms at: http://www.hdsupply.com/email. On 3/29/17, 1:19 AM, "Paul Moore" <p.f.mo...@gmail.com> wrote: >On 28 March 2017 at 22:08, Nelson, Erick <erick.nel...@hdsupply.com> >wrote: >> Try this... > >Thanks for the suggestion - there were some nice improvements in here. > >> def rng = new MersenneTwister() >> >> def roll = { >> rng.nextInt(6) + rng.nextInt(6) + rng.nextInt(6) + 3 >> } > >You changed my definitions to use "def" here. This seems to be the >thing that makes the most difference in performance. I'm really >struggling to find a good explanation as to the effect of using or not >using "def". I had imagined that using "int roll() {..." would be >better, as it explicitly states the types which would help the >compiler avoid the need for generic code. Obviously I was wrong, but >I'm not at all clear why. > >Also, if I use "def rng" but keep "int roll()", I get an error "No >such property: rng". I'm not clear why that is. > >Do you know of a good resource that explains the difference between >using def and not doing so? I'm currently working my way through >"Groovy in Action" and while the subject has been discussed, I didn't >really follow it. I've also looked at the online docs and they haven't >helped a lot. It's quite possible that my confusion comes from the >fact that I only really have a casual knowledge of Java, so the >precise way classes reference properties and variables isn't clear to >me - if there's some background reading in Java that would help >clarify, that would be useful too. > >> int N = 1000000 >> def results = [:].withDefault{0} > >I never knew about withDefault - that's a really nice feature, thanks! > >Thanks for your help, >Paul
