I actually find my version of 3 more readable than the one with the `_`, which looks too much like a partially applied function. It's a minor issue, though.
On Sat, Apr 16, 2016 at 11:56 PM, Hyukjin Kwon <gurwls...@gmail.com> wrote: > Hi Mark, > > I know but that could harm readability. AFAIK, for this reason, that is > not (or rarely) used in Spark. > > 2016-04-17 15:54 GMT+09:00 Mark Hamstra <m...@clearstorydata.com>: > >> FWIW, 3 should work as just `.map(function)`. >> >> On Sat, Apr 16, 2016 at 11:48 PM, Reynold Xin <r...@databricks.com> >> wrote: >> >>> Hi Hyukjin, >>> >>> Thanks for asking. >>> >>> For 1 the change is almost always better. >>> >>> For 2 it depends on the context. In general if the type is not obvious, >>> it helps readability to explicitly declare them. >>> >>> For 3 again it depends on context. >>> >>> >>> So while it is a good idea to change 1 to reflect a more consistent code >>> base (and maybe we should codify it), it is almost always a bad idea to >>> change 2 and 3 just for the sake of changing them. >>> >>> >>> >>> On Sat, Apr 16, 2016 at 11:06 PM, Hyukjin Kwon <gurwls...@gmail.com> >>> wrote: >>> >>>> Hi all, >>>> >>>> First of all, I am sorry that this is relatively trivial and too minor >>>> but I just want to be clear on this and careful for the more PRs in the >>>> future. >>>> >>>> Recently, I have submitted a PR ( >>>> https://github.com/apache/spark/pull/12413) about Scala style and this >>>> was merged. In this PR, I changed >>>> >>>> 1. >>>> >>>> from >>>> >>>> .map(item => { >>>> ... >>>> }) >>>> >>>> to >>>> >>>> .map { item => >>>> ... >>>> } >>>> >>>> >>>> >>>> 2. >>>> from >>>> >>>> words.foreachRDD { (rdd: RDD[String], time: Time) => ... >>>> >>>> to >>>> >>>> words.foreachRDD { (rdd, time) => ... >>>> >>>> >>>> >>>> 3. >>>> >>>> from >>>> >>>> .map { x => >>>> function(x) >>>> } >>>> >>>> to >>>> >>>> .map(function(_)) >>>> >>>> >>>> My question is, I think it looks 2. and 3. are arguable (please see the >>>> discussion in the PR). >>>> I agree that I might not have to change those in the future but I just >>>> wonder if I should revert 2. and 3.. >>>> >>>> FYI, >>>> - The usage of 2. is pretty rare. >>>> - 3. is pretty a lot. but the PR corrects ones like above only when the >>>> val within closure looks obviously meaningless (such as x or a) and with >>>> only single line. >>>> >>>> I would appreciate that if you add some comments and opinions on this. >>>> >>>> Thanks! >>>> >>> >>> >> >
