Hi, Till, Bruno Thank for your reply.
Twitter’s scala programming suggestion is useful. I prefer the alexandru/scala-best-practices. Like this rule `2.16. Public functions SHOULD have an explicit return type`, the class field type explicitly declaring is better for developer to read. [1] https://github.com/alexandru/scala-best-practices/blob/master/sections/2-language-rules.md#216-public-functions-should-have-an-explicit-return-type <https://github.com/alexandru/scala-best-practices/blob/master/sections/2-language-rules.md#216-public-functions-should-have-an-explicit-return-type> Thanks Jinkui Shi > On Jan 27, 2017, at 02:33, Bruno Aranda <brunoara...@gmail.com> wrote: > > Hi, > > Twitter's Effective Scala contains very well-known and accepted conventions > for Scala: > > http://twitter.github.io/effectivescala/ > > Cheers, > > Bruno > > On Thu, 26 Jan 2017 at 14:16 Till Rohrmann <trohrm...@apache.org> wrote: > >> Agreed. I think it's a good idea to annotate the code with as much >> information as possible to help other people to understand it. I think it's >> a good idea to include this information in the coding guidelines. But I'm >> not sure whether we have a dedicated Scala coding guideline. >> >> Cheers, >> Till >> >> On Thu, Jan 26, 2017 at 10:27 AM, Jinkui Shi <shijinkui...@163.com> wrote: >> >>> hi, all >>> >>> Scala can infer the actual type if we didn’t declare its type. There also >>> nothing different in the byte code of java class format. >>> It’s convenient for write the code, but hard to read. Maybe it’s time to >>> face such bad smell code. >>> Scala check style plugin also have such rule. We can add this to the code >>> guidelines. >>> >>> So I have a proposal: Declare all the class field with its type as far as >>> possible in Scala code. The variate in the function can be ignore if >>> necessary. >>> >>> What do you think about this? >>> >>> The test below to show that declare type and type inference are the same >>> after compiling. >>> >>> Thanks >>> Jinkui Shi >>> >>> ------------------------------------------------------------ >>> -------------------------------------- >>> >>> object DeclareTypeTest { >>> >>> def main(args: Array[String]): Unit = { >>> // 1 >>> declareTypeFunction >>> // 2 >>> undeclareTypeFunction >>> } >>> >>> def declareTypeFunction: Int = { >>> 1 >>> } >>> >>> def undeclareTypeFunction: Int = { >>> 1 >>> } >>> } >>> >>> >>> java -c DeclareTypeTest$.class : >>> >>> public void main(java.lang.String[]); >>> Code: >>> 0: aload_0 >>> 1: invokevirtual #18 // Method >>> declareTypeFunction:()I >>> 4: pop >>> 5: aload_0 >>> 6: invokevirtual #21 // Method >>> undeclareTypeFunction:()I >>> 9: pop >>> 10: return >>> >>> public int declareTypeFunction(); >>> Code: >>> 0: iconst_1 >>> 1: ireturn >>> >>> public int undeclareTypeFunction(); >>> Code: >>> 0: iconst_1 >>> 1: ireturn >>> >>> >>> >>
