[DISCUSS] Issues with heterogeneity of the code

[Stephan Ewen]

Hi everyone!

I would like to start an open discussion about some issue with the
heterogeneity of the Flink code base.

We have, since the beginning in Apache (and even since we started the
predecessor project, Stratosphere) refrained from strictly enforcing
conventions like formatting, style, or libraries. I like the idea behind
it, that committers and contributors are not forced into a corset of
hundreds of rules before they can contribute something.

As the project is growing, more and more people with different backgrounds
have joined, and the project has grown a bit heterogeneous in several
parts. In many cases, not necessarily due to need for different
functionality, but simply due to "roll your own style". I think this is
starting to become a bit of an issue.

Here are a few examples:

 - Parameter checking is sometimes done with commons-lang3, commons-lang,
or guava

 - Command line parsing is sometimes done with commons-cli, sometimes with
scopt.

 - Code styles are quite different from commit to commit. Spaces,
indentations, braces. Not a critical thing, but seems to encourage people
to reformat other people's code, whenever the pass over it, which should be
avoided (cluttered diffs, may introduce new bugs actually)

 - Some projects are mixed Java/Scala, which is not perfectly supported by
the tools so far. It also needs many "fromJava / toJava" conversions and
makes the entry hurdle into the project higher.

 - Tests are sometimes written as Java Unit tests, sometimes as Scala Unit
tests (method style), sometimes as Scala Unit Tests (grammar style).

Not all things need to be unified across the entire Flink code base. But it
becomes harder to switch between projects, even for seasoned Flinksters.
And it becomes a hurdle for new contributors, which is very critical.

I, personally, would like to encourage people to keep this in mind. Easier
understanding of the code and easier entry for newcomers (for which a
certain homogeneity helps quite a bit) should have a higher priority than
the desire to stick to the personal favorite code style or library. This is
a big community effort, after all.

That said, we should not, of course, block of the use of new
libraries/languages/features when they have significant benefit over the
existing state.

I am eager to hear opinions!

Stephan

[Szabó Péter]

I agree. A unified rule-set for code style & formatting would make new
contributions easier. There should be also a configuration guide for
different IDEs.

Peter

2015-03-08 23:17 GMT+01:00 Stephan Ewen <[hidden email]>:

> Hi everyone!
>
> I would like to start an open discussion about some issue with the
> heterogeneity of the Flink code base.
>
> We have, since the beginning in Apache (and even since we started the
> predecessor project, Stratosphere) refrained from strictly enforcing
> conventions like formatting, style, or libraries. I like the idea behind
> it, that committers and contributors are not forced into a corset of
> hundreds of rules before they can contribute something.
>
> As the project is growing, more and more people with different backgrounds
> have joined, and the project has grown a bit heterogeneous in several
> parts. In many cases, not necessarily due to need for different
> functionality, but simply due to "roll your own style". I think this is
> starting to become a bit of an issue.
>
> Here are a few examples:
>
>  - Parameter checking is sometimes done with commons-lang3, commons-lang,
> or guava
>
>  - Command line parsing is sometimes done with commons-cli, sometimes with
> scopt.
>
>  - Code styles are quite different from commit to commit. Spaces,
> indentations, braces. Not a critical thing, but seems to encourage people
> to reformat other people's code, whenever the pass over it, which should be
> avoided (cluttered diffs, may introduce new bugs actually)
>
>  - Some projects are mixed Java/Scala, which is not perfectly supported by
> the tools so far. It also needs many "fromJava / toJava" conversions and
> makes the entry hurdle into the project higher.
>
>  - Tests are sometimes written as Java Unit tests, sometimes as Scala Unit
> tests (method style), sometimes as Scala Unit Tests (grammar style).
>
> Not all things need to be unified across the entire Flink code base. But it
> becomes harder to switch between projects, even for seasoned Flinksters.
> And it becomes a hurdle for new contributors, which is very critical.
>
> I, personally, would like to encourage people to keep this in mind. Easier
> understanding of the code and easier entry for newcomers (for which a
> certain homogeneity helps quite a bit) should have a higher priority than
> the desire to stick to the personal favorite code style or library. This is
> a big community effort, after all.
>
> That said, we should not, of course, block of the use of new
> libraries/languages/features when they have significant benefit over the
> existing state.
>
> I am eager to hear opinions!
>
> Stephan
>

[Ufuk Celebi-2]

Hey Stephan,

On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:

> Hi everyone!
>
> I would like to start an open discussion about some issue with the
> heterogeneity of the Flink code base.

Thanks for bringing this up. I agree with your position. The related discussion about using Guava vs. Validate is a good step into the right direction. In general, I think it's super hard to get more homogeneity without enforcing rules (like in the Guava/Validate discussion). I would be OK with trying to settle on rules and then enforcing them. But I'm not sure whether that is what you are asking for? Are you more aiming at a "Let's keep it in mind" kind of thingy?!

> Here are a few examples:
>
> - Parameter checking is sometimes done with commons-lang3, commons-lang,
> or guava
> - Command line parsing is sometimes done with commons-cli, sometimes with
> scopt.

I think these are easily enforceable and could also be changed manually w/o too much hassle.

> - Code styles are quite different from commit to commit. Spaces,
> indentations, braces. Not a critical thing, but seems to encourage people
> to reformat other people's code, whenever the pass over it, which should be
> avoided (cluttered diffs, may introduce new bugs actually)

This is something we could more strictly enforce in pull requests and generally ask people to refrain from.

> - Some projects are mixed Java/Scala, which is not perfectly supported by
> the tools so far. It also needs many "fromJava / toJava" conversions and
> makes the entry hurdle into the project higher.
> - Tests are sometimes written as Java Unit tests, sometimes as Scala Unit
> tests (method style), sometimes as Scala Unit Tests (grammar style).

This is an artifact of the mixed Scala/Java discussion. I agree that this can be problematic, but I'm not sure how to solve this as long as we mix Java/Scala in the same modules?! For new code in the runtime, we could stick to one language. What do you propose here as a solution?

> I am eager to hear opinions!

As I've said, I agree with your points, but I think a big issue for new comers and committers alike is missing documentation in the code. We should try to keep the discussion we had in that regard in mind as well.

– Ufuk

[till.rohrmann]

I also agree that we have too many different ways of doing things. A set of
common rules/ways would definitely be beneficial for the project.

Concerning the command line parsing: I thought that Alexander Alexandrov
wanted to unify the command line parsing by replacing both tools with a
better one. So this should be fixed sooner or later.

The different code styles are just natural if there is no common set of
established rules, which are also enforced. I see two solutions: Either
enforcing common coding rules or refraining from reformatting the code from
other contributors. I don't know whether we can find a common denominator
with which everyone can live and which is yet specific enough to make the
code base more homogenous.

I also agree that the mixed Java/Scala projects make it harder to get
started. I've often seen that people confuse the basic types (Scala tuples
vs. our own tuples, Java list vs. Scala list, etc.). This is probably
something we cannot fix without rewriting parts which are implemented in
the "other" language, though.

Personally I don't see the different testing styles as critical. Whether
one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it should
be pretty obvious for everyone where the testing code is written in case
that they want to change something. Moreover, most of the time you would
not want to change proper defined test cases. In fact, I think that
WordSpecLike and FlatSpec let you write better tests, because it encourages
people to clearly and more naturally write what they want to test. Compared
to some shorter and often not so meaningful junit method names, this is for
me a clear advantage. If a test case fails, I want to directly know without
having to go through the testing code, what was tested and what went
probably wrong. However, this holds only true if we don't use the
JUnitRunner to run these tests. Unfortunately, this is currently the case.
With JUnitRunner, the actual result output of the tests is often hard to
decode. Therefore, we should probably stick to writing testing methods if
we use JUnit to run our Scala tests but use the more expressive FlatSpec
for pure Scala modules.

That said, I would be in favour of some explicitly stated guidelines,
because "Lets' keep it in mind" will be forgotten soon.





On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:

> Hey Stephan,
>
> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
>
> > Hi everyone!
> >
> > I would like to start an open discussion about some issue with the
> > heterogeneity of the Flink code base.
>
> Thanks for bringing this up. I agree with your position. The related
> discussion about using Guava vs. Validate is a good step into the right
> direction. In general, I think it's super hard to get more homogeneity
> without enforcing rules (like in the Guava/Validate discussion). I would be
> OK with trying to settle on rules and then enforcing them. But I'm not sure
> whether that is what you are asking for? Are you more aiming at a "Let's
> keep it in mind" kind of thingy?!
>
> > Here are a few examples:
> >
> > - Parameter checking is sometimes done with commons-lang3, commons-lang,
> > or guava
> > - Command line parsing is sometimes done with commons-cli, sometimes with
> > scopt.
>
> I think these are easily enforceable and could also be changed manually
> w/o too much hassle.
>
> > - Code styles are quite different from commit to commit. Spaces,
> > indentations, braces. Not a critical thing, but seems to encourage people
> > to reformat other people's code, whenever the pass over it, which should
> be
> > avoided (cluttered diffs, may introduce new bugs actually)
>
> This is something we could more strictly enforce in pull requests and
> generally ask people to refrain from.
>
> > - Some projects are mixed Java/Scala, which is not perfectly supported by
> > the tools so far. It also needs many "fromJava / toJava" conversions and
> > makes the entry hurdle into the project higher.
> > - Tests are sometimes written as Java Unit tests, sometimes as Scala Unit
> > tests (method style), sometimes as Scala Unit Tests (grammar style).
>
> This is an artifact of the mixed Scala/Java discussion. I agree that this
> can be problematic, but I'm not sure how to solve this as long as we mix
> Java/Scala in the same modules?! For new code in the runtime, we could
> stick to one language. What do you propose here as a solution?
>
> > I am eager to hear opinions!
>
> As I've said, I agree with your points, but I think a big issue for new
> comers and committers alike is missing documentation in the code. We should
> try to keep the discussion we had in that regard in mind as well.
>
> – Ufuk

[Henry Saputra]

Thanks for bringing up the discussions, Stephan.

Ufuk and Till had brought up some ideas to solve the example of issues
you mentioned in the original thread.
So In the nutshell, we need to have more strick style and rules
checking for the code to help contributors to submit code change and
maintain bit more homogenous in style and code flow.

Some ideas of concrete steps I could think of and have done it in
other projects:
1. Add Google Java code style [1] as the checkstyle rule and document
the differences from the rule (For example, tabs instead of spaces).
Set it as break build if style is violated. We did similar thing in
Tachyon [2] and seemed to help.
2. Declare Scala code style [3] as the main code style for Scala
portion of the code and enforce it. Similar to Java add documentation
for differences or details that is not covered by the rules.
3. Add code guide for stuff which are not covered by the rules, such
as parameter checking to use Guava or common-lang3 and enforce it by
code review. With this do global code change to reflect this.

Just my 2-cents, and as the others had mentioned, we need to make this
as explicit

- Henry

[1] https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
[2] http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
[3] http://docs.scala-lang.org/style/

On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <[hidden email]> wrote:

> I also agree that we have too many different ways of doing things. A set of
> common rules/ways would definitely be beneficial for the project.
>
> Concerning the command line parsing: I thought that Alexander Alexandrov
> wanted to unify the command line parsing by replacing both tools with a
> better one. So this should be fixed sooner or later.
>
> The different code styles are just natural if there is no common set of
> established rules, which are also enforced. I see two solutions: Either
> enforcing common coding rules or refraining from reformatting the code from
> other contributors. I don't know whether we can find a common denominator
> with which everyone can live and which is yet specific enough to make the
> code base more homogenous.
>
> I also agree that the mixed Java/Scala projects make it harder to get
> started. I've often seen that people confuse the basic types (Scala tuples
> vs. our own tuples, Java list vs. Scala list, etc.). This is probably
> something we cannot fix without rewriting parts which are implemented in
> the "other" language, though.
>
> Personally I don't see the different testing styles as critical. Whether
> one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it should
> be pretty obvious for everyone where the testing code is written in case
> that they want to change something. Moreover, most of the time you would
> not want to change proper defined test cases. In fact, I think that
> WordSpecLike and FlatSpec let you write better tests, because it encourages
> people to clearly and more naturally write what they want to test. Compared
> to some shorter and often not so meaningful junit method names, this is for
> me a clear advantage. If a test case fails, I want to directly know without
> having to go through the testing code, what was tested and what went
> probably wrong. However, this holds only true if we don't use the
> JUnitRunner to run these tests. Unfortunately, this is currently the case.
> With JUnitRunner, the actual result output of the tests is often hard to
> decode. Therefore, we should probably stick to writing testing methods if
> we use JUnit to run our Scala tests but use the more expressive FlatSpec
> for pure Scala modules.
>
> That said, I would be in favour of some explicitly stated guidelines,
> because "Lets' keep it in mind" will be forgotten soon.
>
>
>
>
>
> On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:
>
>> Hey Stephan,
>>
>> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
>>
>> > Hi everyone!
>> >
>> > I would like to start an open discussion about some issue with the
>> > heterogeneity of the Flink code base.
>>
>> Thanks for bringing this up. I agree with your position. The related
>> discussion about using Guava vs. Validate is a good step into the right
>> direction. In general, I think it's super hard to get more homogeneity
>> without enforcing rules (like in the Guava/Validate discussion). I would be
>> OK with trying to settle on rules and then enforcing them. But I'm not sure
>> whether that is what you are asking for? Are you more aiming at a "Let's
>> keep it in mind" kind of thingy?!
>>
>> > Here are a few examples:
>> >
>> > - Parameter checking is sometimes done with commons-lang3, commons-lang,
>> > or guava
>> > - Command line parsing is sometimes done with commons-cli, sometimes with
>> > scopt.
>>
>> I think these are easily enforceable and could also be changed manually
>> w/o too much hassle.
>>
>> > - Code styles are quite different from commit to commit. Spaces,
>> > indentations, braces. Not a critical thing, but seems to encourage people
>> > to reformat other people's code, whenever the pass over it, which should
>> be
>> > avoided (cluttered diffs, may introduce new bugs actually)
>>
>> This is something we could more strictly enforce in pull requests and
>> generally ask people to refrain from.
>>
>> > - Some projects are mixed Java/Scala, which is not perfectly supported by
>> > the tools so far. It also needs many "fromJava / toJava" conversions and
>> > makes the entry hurdle into the project higher.
>> > - Tests are sometimes written as Java Unit tests, sometimes as Scala Unit
>> > tests (method style), sometimes as Scala Unit Tests (grammar style).
>>
>> This is an artifact of the mixed Scala/Java discussion. I agree that this
>> can be problematic, but I'm not sure how to solve this as long as we mix
>> Java/Scala in the same modules?! For new code in the runtime, we could
>> stick to one language. What do you propose here as a solution?
>>
>> > I am eager to hear opinions!
>>
>> As I've said, I agree with your points, but I think a big issue for new
>> comers and committers alike is missing documentation in the code. We should
>> try to keep the discussion we had in that regard in mind as well.
>>
>> – Ufuk

[Stephan Ewen]

We already have checkstyle for Java and Scala in place (with marking
violations a breaking the build).

The rules in Java are very loose, though. We may make them stricter. Would
require extensive passes over a lot of code, though, to fix this.

The other things (choice of library) seem to be well addressable and we can
document and enforce them immediately, if we want.

Stephan


On Mon, Mar 9, 2015 at 6:26 PM, Henry Saputra <[hidden email]>
wrote:

> Thanks for bringing up the discussions, Stephan.
>
> Ufuk and Till had brought up some ideas to solve the example of issues
> you mentioned in the original thread.
> So In the nutshell, we need to have more strick style and rules
> checking for the code to help contributors to submit code change and
> maintain bit more homogenous in style and code flow.
>
> Some ideas of concrete steps I could think of and have done it in
> other projects:
> 1. Add Google Java code style [1] as the checkstyle rule and document
> the differences from the rule (For example, tabs instead of spaces).
> Set it as break build if style is violated. We did similar thing in
> Tachyon [2] and seemed to help.
> 2. Declare Scala code style [3] as the main code style for Scala
> portion of the code and enforce it. Similar to Java add documentation
> for differences or details that is not covered by the rules.
> 3. Add code guide for stuff which are not covered by the rules, such
> as parameter checking to use Guava or common-lang3 and enforce it by
> code review. With this do global code change to reflect this.
>
> Just my 2-cents, and as the others had mentioned, we need to make this
> as explicit
>
> - Henry
>
> [1] https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
> [2] http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
> [3] http://docs.scala-lang.org/style/
>
> On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <[hidden email]>
> wrote:
> > I also agree that we have too many different ways of doing things. A set
> of
> > common rules/ways would definitely be beneficial for the project.
> >
> > Concerning the command line parsing: I thought that Alexander Alexandrov
> > wanted to unify the command line parsing by replacing both tools with a
> > better one. So this should be fixed sooner or later.
> >
> > The different code styles are just natural if there is no common set of
> > established rules, which are also enforced. I see two solutions: Either
> > enforcing common coding rules or refraining from reformatting the code
> from
> > other contributors. I don't know whether we can find a common denominator
> > with which everyone can live and which is yet specific enough to make the
> > code base more homogenous.
> >
> > I also agree that the mixed Java/Scala projects make it harder to get
> > started. I've often seen that people confuse the basic types (Scala
> tuples
> > vs. our own tuples, Java list vs. Scala list, etc.). This is probably
> > something we cannot fix without rewriting parts which are implemented in
> > the "other" language, though.
> >
> > Personally I don't see the different testing styles as critical. Whether
> > one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it should
> > be pretty obvious for everyone where the testing code is written in case
> > that they want to change something. Moreover, most of the time you would
> > not want to change proper defined test cases. In fact, I think that
> > WordSpecLike and FlatSpec let you write better tests, because it
> encourages
> > people to clearly and more naturally write what they want to test.
> Compared
> > to some shorter and often not so meaningful junit method names, this is
> for
> > me a clear advantage. If a test case fails, I want to directly know
> without
> > having to go through the testing code, what was tested and what went
> > probably wrong. However, this holds only true if we don't use the
> > JUnitRunner to run these tests. Unfortunately, this is currently the
> case.
> > With JUnitRunner, the actual result output of the tests is often hard to
> > decode. Therefore, we should probably stick to writing testing methods if
> > we use JUnit to run our Scala tests but use the more expressive FlatSpec
> > for pure Scala modules.
> >
> > That said, I would be in favour of some explicitly stated guidelines,
> > because "Lets' keep it in mind" will be forgotten soon.
> >
> >
> >
> >
> >
> > On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:
> >
> >> Hey Stephan,
> >>
> >> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
> >>
> >> > Hi everyone!
> >> >
> >> > I would like to start an open discussion about some issue with the
> >> > heterogeneity of the Flink code base.
> >>
> >> Thanks for bringing this up. I agree with your position. The related
> >> discussion about using Guava vs. Validate is a good step into the right
> >> direction. In general, I think it's super hard to get more homogeneity
> >> without enforcing rules (like in the Guava/Validate discussion). I
> would be
> >> OK with trying to settle on rules and then enforcing them. But I'm not
> sure
> >> whether that is what you are asking for? Are you more aiming at a "Let's
> >> keep it in mind" kind of thingy?!
> >>
> >> > Here are a few examples:
> >> >
> >> > - Parameter checking is sometimes done with commons-lang3,
> commons-lang,
> >> > or guava
> >> > - Command line parsing is sometimes done with commons-cli, sometimes
> with
> >> > scopt.
> >>
> >> I think these are easily enforceable and could also be changed manually
> >> w/o too much hassle.
> >>
> >> > - Code styles are quite different from commit to commit. Spaces,
> >> > indentations, braces. Not a critical thing, but seems to encourage
> people
> >> > to reformat other people's code, whenever the pass over it, which
> should
> >> be
> >> > avoided (cluttered diffs, may introduce new bugs actually)
> >>
> >> This is something we could more strictly enforce in pull requests and
> >> generally ask people to refrain from.
> >>
> >> > - Some projects are mixed Java/Scala, which is not perfectly
> supported by
> >> > the tools so far. It also needs many "fromJava / toJava" conversions
> and
> >> > makes the entry hurdle into the project higher.
> >> > - Tests are sometimes written as Java Unit tests, sometimes as Scala
> Unit
> >> > tests (method style), sometimes as Scala Unit Tests (grammar style).
> >>
> >> This is an artifact of the mixed Scala/Java discussion. I agree that
> this
> >> can be problematic, but I'm not sure how to solve this as long as we mix
> >> Java/Scala in the same modules?! For new code in the runtime, we could
> >> stick to one language. What do you propose here as a solution?
> >>
> >> > I am eager to hear opinions!
> >>
> >> As I've said, I agree with your points, but I think a big issue for new
> >> comers and committers alike is missing documentation in the code. We
> should
> >> try to keep the discussion we had in that regard in mind as well.
> >>
> >> – Ufuk
>

[Henry Saputra]

Regarding style, yes, we already have them in place but they are very
loose, especially in Java.

I guess it is a "no good deed goes unpunished" scenario. To tighten up
the style rules, for example following Google Java style with some
documented exceptions, will require massive code changes.
But we already do large code changes or refactoring in some parts of
the code tree. Some current PRs are already huge in size.


- Henry

On Fri, Mar 13, 2015 at 11:51 AM, Stephan Ewen <[hidden email]> wrote:

> We already have checkstyle for Java and Scala in place (with marking
> violations a breaking the build).
>
> The rules in Java are very loose, though. We may make them stricter. Would
> require extensive passes over a lot of code, though, to fix this.
>
> The other things (choice of library) seem to be well addressable and we can
> document and enforce them immediately, if we want.
>
> Stephan
>
>
> On Mon, Mar 9, 2015 at 6:26 PM, Henry Saputra <[hidden email]>
> wrote:
>
>> Thanks for bringing up the discussions, Stephan.
>>
>> Ufuk and Till had brought up some ideas to solve the example of issues
>> you mentioned in the original thread.
>> So In the nutshell, we need to have more strick style and rules
>> checking for the code to help contributors to submit code change and
>> maintain bit more homogenous in style and code flow.
>>
>> Some ideas of concrete steps I could think of and have done it in
>> other projects:
>> 1. Add Google Java code style [1] as the checkstyle rule and document
>> the differences from the rule (For example, tabs instead of spaces).
>> Set it as break build if style is violated. We did similar thing in
>> Tachyon [2] and seemed to help.
>> 2. Declare Scala code style [3] as the main code style for Scala
>> portion of the code and enforce it. Similar to Java add documentation
>> for differences or details that is not covered by the rules.
>> 3. Add code guide for stuff which are not covered by the rules, such
>> as parameter checking to use Guava or common-lang3 and enforce it by
>> code review. With this do global code change to reflect this.
>>
>> Just my 2-cents, and as the others had mentioned, we need to make this
>> as explicit
>>
>> - Henry
>>
>> [1] https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
>> [2] http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
>> [3] http://docs.scala-lang.org/style/
>>
>> On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <[hidden email]>
>> wrote:
>> > I also agree that we have too many different ways of doing things. A set
>> of
>> > common rules/ways would definitely be beneficial for the project.
>> >
>> > Concerning the command line parsing: I thought that Alexander Alexandrov
>> > wanted to unify the command line parsing by replacing both tools with a
>> > better one. So this should be fixed sooner or later.
>> >
>> > The different code styles are just natural if there is no common set of
>> > established rules, which are also enforced. I see two solutions: Either
>> > enforcing common coding rules or refraining from reformatting the code
>> from
>> > other contributors. I don't know whether we can find a common denominator
>> > with which everyone can live and which is yet specific enough to make the
>> > code base more homogenous.
>> >
>> > I also agree that the mixed Java/Scala projects make it harder to get
>> > started. I've often seen that people confuse the basic types (Scala
>> tuples
>> > vs. our own tuples, Java list vs. Scala list, etc.). This is probably
>> > something we cannot fix without rewriting parts which are implemented in
>> > the "other" language, though.
>> >
>> > Personally I don't see the different testing styles as critical. Whether
>> > one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it should
>> > be pretty obvious for everyone where the testing code is written in case
>> > that they want to change something. Moreover, most of the time you would
>> > not want to change proper defined test cases. In fact, I think that
>> > WordSpecLike and FlatSpec let you write better tests, because it
>> encourages
>> > people to clearly and more naturally write what they want to test.
>> Compared
>> > to some shorter and often not so meaningful junit method names, this is
>> for
>> > me a clear advantage. If a test case fails, I want to directly know
>> without
>> > having to go through the testing code, what was tested and what went
>> > probably wrong. However, this holds only true if we don't use the
>> > JUnitRunner to run these tests. Unfortunately, this is currently the
>> case.
>> > With JUnitRunner, the actual result output of the tests is often hard to
>> > decode. Therefore, we should probably stick to writing testing methods if
>> > we use JUnit to run our Scala tests but use the more expressive FlatSpec
>> > for pure Scala modules.
>> >
>> > That said, I would be in favour of some explicitly stated guidelines,
>> > because "Lets' keep it in mind" will be forgotten soon.
>> >
>> >
>> >
>> >
>> >
>> > On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:
>> >
>> >> Hey Stephan,
>> >>
>> >> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
>> >>
>> >> > Hi everyone!
>> >> >
>> >> > I would like to start an open discussion about some issue with the
>> >> > heterogeneity of the Flink code base.
>> >>
>> >> Thanks for bringing this up. I agree with your position. The related
>> >> discussion about using Guava vs. Validate is a good step into the right
>> >> direction. In general, I think it's super hard to get more homogeneity
>> >> without enforcing rules (like in the Guava/Validate discussion). I
>> would be
>> >> OK with trying to settle on rules and then enforcing them. But I'm not
>> sure
>> >> whether that is what you are asking for? Are you more aiming at a "Let's
>> >> keep it in mind" kind of thingy?!
>> >>
>> >> > Here are a few examples:
>> >> >
>> >> > - Parameter checking is sometimes done with commons-lang3,
>> commons-lang,
>> >> > or guava
>> >> > - Command line parsing is sometimes done with commons-cli, sometimes
>> with
>> >> > scopt.
>> >>
>> >> I think these are easily enforceable and could also be changed manually
>> >> w/o too much hassle.
>> >>
>> >> > - Code styles are quite different from commit to commit. Spaces,
>> >> > indentations, braces. Not a critical thing, but seems to encourage
>> people
>> >> > to reformat other people's code, whenever the pass over it, which
>> should
>> >> be
>> >> > avoided (cluttered diffs, may introduce new bugs actually)
>> >>
>> >> This is something we could more strictly enforce in pull requests and
>> >> generally ask people to refrain from.
>> >>
>> >> > - Some projects are mixed Java/Scala, which is not perfectly
>> supported by
>> >> > the tools so far. It also needs many "fromJava / toJava" conversions
>> and
>> >> > makes the entry hurdle into the project higher.
>> >> > - Tests are sometimes written as Java Unit tests, sometimes as Scala
>> Unit
>> >> > tests (method style), sometimes as Scala Unit Tests (grammar style).
>> >>
>> >> This is an artifact of the mixed Scala/Java discussion. I agree that
>> this
>> >> can be problematic, but I'm not sure how to solve this as long as we mix
>> >> Java/Scala in the same modules?! For new code in the runtime, we could
>> >> stick to one language. What do you propose here as a solution?
>> >>
>> >> > I am eager to hear opinions!
>> >>
>> >> As I've said, I agree with your points, but I think a big issue for new
>> >> comers and committers alike is missing documentation in the code. We
>> should
>> >> try to keep the discussion we had in that regard in mind as well.
>> >>
>> >> – Ufuk
>>

[Fabian Hueske-2]

I personally find the Google code style to be too strict/detailed.
Loosening it by dropping certain rules makes only sense if the deviation
does not become to large.

My major concern with adding a such strict code style is that all open PRs
would become invalid.
We could try to reduce that effect by adding the code styling module by
module and primarily resolving PRs that address the next module.
However, this would still be a huge effort and I am not sure if it would
pay back.

In any case, it is good to have this discussion now.
Postponing the decision will make it only more costly if we agree on a more
rigid code style.


2015-03-13 20:18 GMT+01:00 Henry Saputra <[hidden email]>:

> Regarding style, yes, we already have them in place but they are very
> loose, especially in Java.
>
> I guess it is a "no good deed goes unpunished" scenario. To tighten up
> the style rules, for example following Google Java style with some
> documented exceptions, will require massive code changes.
> But we already do large code changes or refactoring in some parts of
> the code tree. Some current PRs are already huge in size.
>
>
> - Henry
>
> On Fri, Mar 13, 2015 at 11:51 AM, Stephan Ewen <[hidden email]> wrote:
> > We already have checkstyle for Java and Scala in place (with marking
> > violations a breaking the build).
> >
> > The rules in Java are very loose, though. We may make them stricter.
> Would
> > require extensive passes over a lot of code, though, to fix this.
> >
> > The other things (choice of library) seem to be well addressable and we
> can
> > document and enforce them immediately, if we want.
> >
> > Stephan
> >
> >
> > On Mon, Mar 9, 2015 at 6:26 PM, Henry Saputra <[hidden email]>
> > wrote:
> >
> >> Thanks for bringing up the discussions, Stephan.
> >>
> >> Ufuk and Till had brought up some ideas to solve the example of issues
> >> you mentioned in the original thread.
> >> So In the nutshell, we need to have more strick style and rules
> >> checking for the code to help contributors to submit code change and
> >> maintain bit more homogenous in style and code flow.
> >>
> >> Some ideas of concrete steps I could think of and have done it in
> >> other projects:
> >> 1. Add Google Java code style [1] as the checkstyle rule and document
> >> the differences from the rule (For example, tabs instead of spaces).
> >> Set it as break build if style is violated. We did similar thing in
> >> Tachyon [2] and seemed to help.
> >> 2. Declare Scala code style [3] as the main code style for Scala
> >> portion of the code and enforce it. Similar to Java add documentation
> >> for differences or details that is not covered by the rules.
> >> 3. Add code guide for stuff which are not covered by the rules, such
> >> as parameter checking to use Guava or common-lang3 and enforce it by
> >> code review. With this do global code change to reflect this.
> >>
> >> Just my 2-cents, and as the others had mentioned, we need to make this
> >> as explicit
> >>
> >> - Henry
> >>
> >> [1] https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
> >> [2] http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
> >> [3] http://docs.scala-lang.org/style/
> >>
> >> On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <[hidden email]>
> >> wrote:
> >> > I also agree that we have too many different ways of doing things. A
> set
> >> of
> >> > common rules/ways would definitely be beneficial for the project.
> >> >
> >> > Concerning the command line parsing: I thought that Alexander
> Alexandrov
> >> > wanted to unify the command line parsing by replacing both tools with
> a
> >> > better one. So this should be fixed sooner or later.
> >> >
> >> > The different code styles are just natural if there is no common set
> of
> >> > established rules, which are also enforced. I see two solutions:
> Either
> >> > enforcing common coding rules or refraining from reformatting the code
> >> from
> >> > other contributors. I don't know whether we can find a common
> denominator
> >> > with which everyone can live and which is yet specific enough to make
> the
> >> > code base more homogenous.
> >> >
> >> > I also agree that the mixed Java/Scala projects make it harder to get
> >> > started. I've often seen that people confuse the basic types (Scala
> >> tuples
> >> > vs. our own tuples, Java list vs. Scala list, etc.). This is probably
> >> > something we cannot fix without rewriting parts which are implemented
> in
> >> > the "other" language, though.
> >> >
> >> > Personally I don't see the different testing styles as critical.
> Whether
> >> > one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it
> should
> >> > be pretty obvious for everyone where the testing code is written in
> case
> >> > that they want to change something. Moreover, most of the time you
> would
> >> > not want to change proper defined test cases. In fact, I think that
> >> > WordSpecLike and FlatSpec let you write better tests, because it
> >> encourages
> >> > people to clearly and more naturally write what they want to test.
> >> Compared
> >> > to some shorter and often not so meaningful junit method names, this
> is
> >> for
> >> > me a clear advantage. If a test case fails, I want to directly know
> >> without
> >> > having to go through the testing code, what was tested and what went
> >> > probably wrong. However, this holds only true if we don't use the
> >> > JUnitRunner to run these tests. Unfortunately, this is currently the
> >> case.
> >> > With JUnitRunner, the actual result output of the tests is often hard
> to
> >> > decode. Therefore, we should probably stick to writing testing
> methods if
> >> > we use JUnit to run our Scala tests but use the more expressive
> FlatSpec
> >> > for pure Scala modules.
> >> >
> >> > That said, I would be in favour of some explicitly stated guidelines,
> >> > because "Lets' keep it in mind" will be forgotten soon.
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:
> >> >
> >> >> Hey Stephan,
> >> >>
> >> >> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
> >> >>
> >> >> > Hi everyone!
> >> >> >
> >> >> > I would like to start an open discussion about some issue with the
> >> >> > heterogeneity of the Flink code base.
> >> >>
> >> >> Thanks for bringing this up. I agree with your position. The related
> >> >> discussion about using Guava vs. Validate is a good step into the
> right
> >> >> direction. In general, I think it's super hard to get more
> homogeneity
> >> >> without enforcing rules (like in the Guava/Validate discussion). I
> >> would be
> >> >> OK with trying to settle on rules and then enforcing them. But I'm
> not
> >> sure
> >> >> whether that is what you are asking for? Are you more aiming at a
> "Let's
> >> >> keep it in mind" kind of thingy?!
> >> >>
> >> >> > Here are a few examples:
> >> >> >
> >> >> > - Parameter checking is sometimes done with commons-lang3,
> >> commons-lang,
> >> >> > or guava
> >> >> > - Command line parsing is sometimes done with commons-cli,
> sometimes
> >> with
> >> >> > scopt.
> >> >>
> >> >> I think these are easily enforceable and could also be changed
> manually
> >> >> w/o too much hassle.
> >> >>
> >> >> > - Code styles are quite different from commit to commit. Spaces,
> >> >> > indentations, braces. Not a critical thing, but seems to encourage
> >> people
> >> >> > to reformat other people's code, whenever the pass over it, which
> >> should
> >> >> be
> >> >> > avoided (cluttered diffs, may introduce new bugs actually)
> >> >>
> >> >> This is something we could more strictly enforce in pull requests and
> >> >> generally ask people to refrain from.
> >> >>
> >> >> > - Some projects are mixed Java/Scala, which is not perfectly
> >> supported by
> >> >> > the tools so far. It also needs many "fromJava / toJava"
> conversions
> >> and
> >> >> > makes the entry hurdle into the project higher.
> >> >> > - Tests are sometimes written as Java Unit tests, sometimes as
> Scala
> >> Unit
> >> >> > tests (method style), sometimes as Scala Unit Tests (grammar
> style).
> >> >>
> >> >> This is an artifact of the mixed Scala/Java discussion. I agree that
> >> this
> >> >> can be problematic, but I'm not sure how to solve this as long as we
> mix
> >> >> Java/Scala in the same modules?! For new code in the runtime, we
> could
> >> >> stick to one language. What do you propose here as a solution?
> >> >>
> >> >> > I am eager to hear opinions!
> >> >>
> >> >> As I've said, I agree with your points, but I think a big issue for
> new
> >> >> comers and committers alike is missing documentation in the code. We
> >> should
> >> >> try to keep the discussion we had in that regard in mind as well.
> >> >>
> >> >> – Ufuk
> >>
>

[Henry Saputra]

Agree.

We have make decision either to play tight or loose on the code style and guide.
Once the codebase is getting too large and more committers coming in
then it would be too late.

We can not have our cake and eat it too.

Looking forward to what others think since I already have my 2-cents out =)

- Henry

On Fri, Mar 13, 2015 at 2:31 PM, Fabian Hueske <[hidden email]> wrote:

> I personally find the Google code style to be too strict/detailed.
> Loosening it by dropping certain rules makes only sense if the deviation
> does not become to large.
>
> My major concern with adding a such strict code style is that all open PRs
> would become invalid.
> We could try to reduce that effect by adding the code styling module by
> module and primarily resolving PRs that address the next module.
> However, this would still be a huge effort and I am not sure if it would
> pay back.
>
> In any case, it is good to have this discussion now.
> Postponing the decision will make it only more costly if we agree on a more
> rigid code style.
>
>
> 2015-03-13 20:18 GMT+01:00 Henry Saputra <[hidden email]>:
>
>> Regarding style, yes, we already have them in place but they are very
>> loose, especially in Java.
>>
>> I guess it is a "no good deed goes unpunished" scenario. To tighten up
>> the style rules, for example following Google Java style with some
>> documented exceptions, will require massive code changes.
>> But we already do large code changes or refactoring in some parts of
>> the code tree. Some current PRs are already huge in size.
>>
>>
>> - Henry
>>
>> On Fri, Mar 13, 2015 at 11:51 AM, Stephan Ewen <[hidden email]> wrote:
>> > We already have checkstyle for Java and Scala in place (with marking
>> > violations a breaking the build).
>> >
>> > The rules in Java are very loose, though. We may make them stricter.
>> Would
>> > require extensive passes over a lot of code, though, to fix this.
>> >
>> > The other things (choice of library) seem to be well addressable and we
>> can
>> > document and enforce them immediately, if we want.
>> >
>> > Stephan
>> >
>> >
>> > On Mon, Mar 9, 2015 at 6:26 PM, Henry Saputra <[hidden email]>
>> > wrote:
>> >
>> >> Thanks for bringing up the discussions, Stephan.
>> >>
>> >> Ufuk and Till had brought up some ideas to solve the example of issues
>> >> you mentioned in the original thread.
>> >> So In the nutshell, we need to have more strick style and rules
>> >> checking for the code to help contributors to submit code change and
>> >> maintain bit more homogenous in style and code flow.
>> >>
>> >> Some ideas of concrete steps I could think of and have done it in
>> >> other projects:
>> >> 1. Add Google Java code style [1] as the checkstyle rule and document
>> >> the differences from the rule (For example, tabs instead of spaces).
>> >> Set it as break build if style is violated. We did similar thing in
>> >> Tachyon [2] and seemed to help.
>> >> 2. Declare Scala code style [3] as the main code style for Scala
>> >> portion of the code and enforce it. Similar to Java add documentation
>> >> for differences or details that is not covered by the rules.
>> >> 3. Add code guide for stuff which are not covered by the rules, such
>> >> as parameter checking to use Guava or common-lang3 and enforce it by
>> >> code review. With this do global code change to reflect this.
>> >>
>> >> Just my 2-cents, and as the others had mentioned, we need to make this
>> >> as explicit
>> >>
>> >> - Henry
>> >>
>> >> [1] https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
>> >> [2] http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
>> >> [3] http://docs.scala-lang.org/style/
>> >>
>> >> On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <[hidden email]>
>> >> wrote:
>> >> > I also agree that we have too many different ways of doing things. A
>> set
>> >> of
>> >> > common rules/ways would definitely be beneficial for the project.
>> >> >
>> >> > Concerning the command line parsing: I thought that Alexander
>> Alexandrov
>> >> > wanted to unify the command line parsing by replacing both tools with
>> a
>> >> > better one. So this should be fixed sooner or later.
>> >> >
>> >> > The different code styles are just natural if there is no common set
>> of
>> >> > established rules, which are also enforced. I see two solutions:
>> Either
>> >> > enforcing common coding rules or refraining from reformatting the code
>> >> from
>> >> > other contributors. I don't know whether we can find a common
>> denominator
>> >> > with which everyone can live and which is yet specific enough to make
>> the
>> >> > code base more homogenous.
>> >> >
>> >> > I also agree that the mixed Java/Scala projects make it harder to get
>> >> > started. I've often seen that people confuse the basic types (Scala
>> >> tuples
>> >> > vs. our own tuples, Java list vs. Scala list, etc.). This is probably
>> >> > something we cannot fix without rewriting parts which are implemented
>> in
>> >> > the "other" language, though.
>> >> >
>> >> > Personally I don't see the different testing styles as critical.
>> Whether
>> >> > one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it
>> should
>> >> > be pretty obvious for everyone where the testing code is written in
>> case
>> >> > that they want to change something. Moreover, most of the time you
>> would
>> >> > not want to change proper defined test cases. In fact, I think that
>> >> > WordSpecLike and FlatSpec let you write better tests, because it
>> >> encourages
>> >> > people to clearly and more naturally write what they want to test.
>> >> Compared
>> >> > to some shorter and often not so meaningful junit method names, this
>> is
>> >> for
>> >> > me a clear advantage. If a test case fails, I want to directly know
>> >> without
>> >> > having to go through the testing code, what was tested and what went
>> >> > probably wrong. However, this holds only true if we don't use the
>> >> > JUnitRunner to run these tests. Unfortunately, this is currently the
>> >> case.
>> >> > With JUnitRunner, the actual result output of the tests is often hard
>> to
>> >> > decode. Therefore, we should probably stick to writing testing
>> methods if
>> >> > we use JUnit to run our Scala tests but use the more expressive
>> FlatSpec
>> >> > for pure Scala modules.
>> >> >
>> >> > That said, I would be in favour of some explicitly stated guidelines,
>> >> > because "Lets' keep it in mind" will be forgotten soon.
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]> wrote:
>> >> >
>> >> >> Hey Stephan,
>> >> >>
>> >> >> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
>> >> >>
>> >> >> > Hi everyone!
>> >> >> >
>> >> >> > I would like to start an open discussion about some issue with the
>> >> >> > heterogeneity of the Flink code base.
>> >> >>
>> >> >> Thanks for bringing this up. I agree with your position. The related
>> >> >> discussion about using Guava vs. Validate is a good step into the
>> right
>> >> >> direction. In general, I think it's super hard to get more
>> homogeneity
>> >> >> without enforcing rules (like in the Guava/Validate discussion). I
>> >> would be
>> >> >> OK with trying to settle on rules and then enforcing them. But I'm
>> not
>> >> sure
>> >> >> whether that is what you are asking for? Are you more aiming at a
>> "Let's
>> >> >> keep it in mind" kind of thingy?!
>> >> >>
>> >> >> > Here are a few examples:
>> >> >> >
>> >> >> > - Parameter checking is sometimes done with commons-lang3,
>> >> commons-lang,
>> >> >> > or guava
>> >> >> > - Command line parsing is sometimes done with commons-cli,
>> sometimes
>> >> with
>> >> >> > scopt.
>> >> >>
>> >> >> I think these are easily enforceable and could also be changed
>> manually
>> >> >> w/o too much hassle.
>> >> >>
>> >> >> > - Code styles are quite different from commit to commit. Spaces,
>> >> >> > indentations, braces. Not a critical thing, but seems to encourage
>> >> people
>> >> >> > to reformat other people's code, whenever the pass over it, which
>> >> should
>> >> >> be
>> >> >> > avoided (cluttered diffs, may introduce new bugs actually)
>> >> >>
>> >> >> This is something we could more strictly enforce in pull requests and
>> >> >> generally ask people to refrain from.
>> >> >>
>> >> >> > - Some projects are mixed Java/Scala, which is not perfectly
>> >> supported by
>> >> >> > the tools so far. It also needs many "fromJava / toJava"
>> conversions
>> >> and
>> >> >> > makes the entry hurdle into the project higher.
>> >> >> > - Tests are sometimes written as Java Unit tests, sometimes as
>> Scala
>> >> Unit
>> >> >> > tests (method style), sometimes as Scala Unit Tests (grammar
>> style).
>> >> >>
>> >> >> This is an artifact of the mixed Scala/Java discussion. I agree that
>> >> this
>> >> >> can be problematic, but I'm not sure how to solve this as long as we
>> mix
>> >> >> Java/Scala in the same modules?! For new code in the runtime, we
>> could
>> >> >> stick to one language. What do you propose here as a solution?
>> >> >>
>> >> >> > I am eager to hear opinions!
>> >> >>
>> >> >> As I've said, I agree with your points, but I think a big issue for
>> new
>> >> >> comers and committers alike is missing documentation in the code. We
>> >> should
>> >> >> try to keep the discussion we had in that regard in mind as well.
>> >> >>
>> >> >> – Ufuk
>> >>
>>

[Aljoscha Krettek-2]

I'm in favor of strict coding styles. And I like the google style.

But I can adapt. 😀
On Mar 13, 2015 11:26 PM, "Henry Saputra" <[hidden email]> wrote:

> Agree.
>
> We have make decision either to play tight or loose on the code style and
> guide.
> Once the codebase is getting too large and more committers coming in
> then it would be too late.
>
> We can not have our cake and eat it too.
>
> Looking forward to what others think since I already have my 2-cents out =)
>
> - Henry
>
> On Fri, Mar 13, 2015 at 2:31 PM, Fabian Hueske <[hidden email]> wrote:
> > I personally find the Google code style to be too strict/detailed.
> > Loosening it by dropping certain rules makes only sense if the deviation
> > does not become to large.
> >
> > My major concern with adding a such strict code style is that all open
> PRs
> > would become invalid.
> > We could try to reduce that effect by adding the code styling module by
> > module and primarily resolving PRs that address the next module.
> > However, this would still be a huge effort and I am not sure if it would
> > pay back.
> >
> > In any case, it is good to have this discussion now.
> > Postponing the decision will make it only more costly if we agree on a
> more
> > rigid code style.
> >
> >
> > 2015-03-13 20:18 GMT+01:00 Henry Saputra <[hidden email]>:
> >
> >> Regarding style, yes, we already have them in place but they are very
> >> loose, especially in Java.
> >>
> >> I guess it is a "no good deed goes unpunished" scenario. To tighten up
> >> the style rules, for example following Google Java style with some
> >> documented exceptions, will require massive code changes.
> >> But we already do large code changes or refactoring in some parts of
> >> the code tree. Some current PRs are already huge in size.
> >>
> >>
> >> - Henry
> >>
> >> On Fri, Mar 13, 2015 at 11:51 AM, Stephan Ewen <[hidden email]>
> wrote:
> >> > We already have checkstyle for Java and Scala in place (with marking
> >> > violations a breaking the build).
> >> >
> >> > The rules in Java are very loose, though. We may make them stricter.
> >> Would
> >> > require extensive passes over a lot of code, though, to fix this.
> >> >
> >> > The other things (choice of library) seem to be well addressable and
> we
> >> can
> >> > document and enforce them immediately, if we want.
> >> >
> >> > Stephan
> >> >
> >> >
> >> > On Mon, Mar 9, 2015 at 6:26 PM, Henry Saputra <
> [hidden email]>
> >> > wrote:
> >> >
> >> >> Thanks for bringing up the discussions, Stephan.
> >> >>
> >> >> Ufuk and Till had brought up some ideas to solve the example of
> issues
> >> >> you mentioned in the original thread.
> >> >> So In the nutshell, we need to have more strick style and rules
> >> >> checking for the code to help contributors to submit code change and
> >> >> maintain bit more homogenous in style and code flow.
> >> >>
> >> >> Some ideas of concrete steps I could think of and have done it in
> >> >> other projects:
> >> >> 1. Add Google Java code style [1] as the checkstyle rule and document
> >> >> the differences from the rule (For example, tabs instead of spaces).
> >> >> Set it as break build if style is violated. We did similar thing in
> >> >> Tachyon [2] and seemed to help.
> >> >> 2. Declare Scala code style [3] as the main code style for Scala
> >> >> portion of the code and enforce it. Similar to Java add documentation
> >> >> for differences or details that is not covered by the rules.
> >> >> 3. Add code guide for stuff which are not covered by the rules, such
> >> >> as parameter checking to use Guava or common-lang3 and enforce it by
> >> >> code review. With this do global code change to reflect this.
> >> >>
> >> >> Just my 2-cents, and as the others had mentioned, we need to make
> this
> >> >> as explicit
> >> >>
> >> >> - Henry
> >> >>
> >> >> [1]
> https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
> >> >> [2]
> http://tachyon-project.org/Startup-Tasks-for-New-Contributors.html
> >> >> [3] http://docs.scala-lang.org/style/
> >> >>
> >> >> On Mon, Mar 9, 2015 at 2:35 AM, Till Rohrmann <
> [hidden email]>
> >> >> wrote:
> >> >> > I also agree that we have too many different ways of doing things.
> A
> >> set
> >> >> of
> >> >> > common rules/ways would definitely be beneficial for the project.
> >> >> >
> >> >> > Concerning the command line parsing: I thought that Alexander
> >> Alexandrov
> >> >> > wanted to unify the command line parsing by replacing both tools
> with
> >> a
> >> >> > better one. So this should be fixed sooner or later.
> >> >> >
> >> >> > The different code styles are just natural if there is no common
> set
> >> of
> >> >> > established rules, which are also enforced. I see two solutions:
> >> Either
> >> >> > enforcing common coding rules or refraining from reformatting the
> code
> >> >> from
> >> >> > other contributors. I don't know whether we can find a common
> >> denominator
> >> >> > with which everyone can live and which is yet specific enough to
> make
> >> the
> >> >> > code base more homogenous.
> >> >> >
> >> >> > I also agree that the mixed Java/Scala projects make it harder to
> get
> >> >> > started. I've often seen that people confuse the basic types (Scala
> >> >> tuples
> >> >> > vs. our own tuples, Java list vs. Scala list, etc.). This is
> probably
> >> >> > something we cannot fix without rewriting parts which are
> implemented
> >> in
> >> >> > the "other" language, though.
> >> >> >
> >> >> > Personally I don't see the different testing styles as critical.
> >> Whether
> >> >> > one is using JUnit tests, WordSpecLike tests or FlatSpec tests, it
> >> should
> >> >> > be pretty obvious for everyone where the testing code is written in
> >> case
> >> >> > that they want to change something. Moreover, most of the time you
> >> would
> >> >> > not want to change proper defined test cases. In fact, I think that
> >> >> > WordSpecLike and FlatSpec let you write better tests, because it
> >> >> encourages
> >> >> > people to clearly and more naturally write what they want to test.
> >> >> Compared
> >> >> > to some shorter and often not so meaningful junit method names,
> this
> >> is
> >> >> for
> >> >> > me a clear advantage. If a test case fails, I want to directly know
> >> >> without
> >> >> > having to go through the testing code, what was tested and what
> went
> >> >> > probably wrong. However, this holds only true if we don't use the
> >> >> > JUnitRunner to run these tests. Unfortunately, this is currently
> the
> >> >> case.
> >> >> > With JUnitRunner, the actual result output of the tests is often
> hard
> >> to
> >> >> > decode. Therefore, we should probably stick to writing testing
> >> methods if
> >> >> > we use JUnit to run our Scala tests but use the more expressive
> >> FlatSpec
> >> >> > for pure Scala modules.
> >> >> >
> >> >> > That said, I would be in favour of some explicitly stated
> guidelines,
> >> >> > because "Lets' keep it in mind" will be forgotten soon.
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> > On Mon, Mar 9, 2015 at 8:46 AM, Ufuk Celebi <[hidden email]>
> wrote:
> >> >> >
> >> >> >> Hey Stephan,
> >> >> >>
> >> >> >> On 08 Mar 2015, at 23:17, Stephan Ewen <[hidden email]> wrote:
> >> >> >>
> >> >> >> > Hi everyone!
> >> >> >> >
> >> >> >> > I would like to start an open discussion about some issue with
> the
> >> >> >> > heterogeneity of the Flink code base.
> >> >> >>
> >> >> >> Thanks for bringing this up. I agree with your position. The
> related
> >> >> >> discussion about using Guava vs. Validate is a good step into the
> >> right
> >> >> >> direction. In general, I think it's super hard to get more
> >> homogeneity
> >> >> >> without enforcing rules (like in the Guava/Validate discussion). I
> >> >> would be
> >> >> >> OK with trying to settle on rules and then enforcing them. But I'm
> >> not
> >> >> sure
> >> >> >> whether that is what you are asking for? Are you more aiming at a
> >> "Let's
> >> >> >> keep it in mind" kind of thingy?!
> >> >> >>
> >> >> >> > Here are a few examples:
> >> >> >> >
> >> >> >> > - Parameter checking is sometimes done with commons-lang3,
> >> >> commons-lang,
> >> >> >> > or guava
> >> >> >> > - Command line parsing is sometimes done with commons-cli,
> >> sometimes
> >> >> with
> >> >> >> > scopt.
> >> >> >>
> >> >> >> I think these are easily enforceable and could also be changed
> >> manually
> >> >> >> w/o too much hassle.
> >> >> >>
> >> >> >> > - Code styles are quite different from commit to commit. Spaces,
> >> >> >> > indentations, braces. Not a critical thing, but seems to
> encourage
> >> >> people
> >> >> >> > to reformat other people's code, whenever the pass over it,
> which
> >> >> should
> >> >> >> be
> >> >> >> > avoided (cluttered diffs, may introduce new bugs actually)
> >> >> >>
> >> >> >> This is something we could more strictly enforce in pull requests
> and
> >> >> >> generally ask people to refrain from.
> >> >> >>
> >> >> >> > - Some projects are mixed Java/Scala, which is not perfectly
> >> >> supported by
> >> >> >> > the tools so far. It also needs many "fromJava / toJava"
> >> conversions
> >> >> and
> >> >> >> > makes the entry hurdle into the project higher.
> >> >> >> > - Tests are sometimes written as Java Unit tests, sometimes as
> >> Scala
> >> >> Unit
> >> >> >> > tests (method style), sometimes as Scala Unit Tests (grammar
> >> style).
> >> >> >>
> >> >> >> This is an artifact of the mixed Scala/Java discussion. I agree
> that
> >> >> this
> >> >> >> can be problematic, but I'm not sure how to solve this as long as
> we
> >> mix
> >> >> >> Java/Scala in the same modules?! For new code in the runtime, we
> >> could
> >> >> >> stick to one language. What do you propose here as a solution?
> >> >> >>
> >> >> >> > I am eager to hear opinions!
> >> >> >>
> >> >> >> As I've said, I agree with your points, but I think a big issue
> for
> >> new
> >> >> >> comers and committers alike is missing documentation in the code.
> We
> >> >> should
> >> >> >> try to keep the discussion we had in that regard in mind as well.
> >> >> >>
> >> >> >> – Ufuk
> >> >>
> >>
>

[Ufuk Celebi-2]

On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]> wrote:

> I'm in favor of strict coding styles. And I like the google style.


+1 I would like that. We essentially all agree that we want more
homogeneity and I think strict rules are the only way to go. Since this is
a very subjective matter it makes sense to go with something (somewhat) well
established like the Google code style.

[mxm]

+1 for enforcing a more strict Java code style. However, let's not
introduce a line legth of 100 like in Scala. I think that's hurting
readability of the code.

On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]> wrote:

> On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]> wrote:
>
> > I'm in favor of strict coding styles. And I like the google style.
>
>
> +1 I would like that. We essentially all agree that we want more
> homogeneity and I think strict rules are the only way to go. Since this is
> a very subjective matter it makes sense to go with something (somewhat)
> well
> established like the Google code style.
>

[Stephan Ewen]

+1 for not limiting the line length. Everyone should have a good sense to
break lines. When in exceptional cases people violate this, it is usually
for a good reason.

On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <[hidden email]> wrote:

> +1 for enforcing a more strict Java code style. However, let's not
> introduce a line legth of 100 like in Scala. I think that's hurting
> readability of the code.
>
> On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]> wrote:
>
> > On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]>
> wrote:
> >
> > > I'm in favor of strict coding styles. And I like the google style.
> >
> >
> > +1 I would like that. We essentially all agree that we want more
> > homogeneity and I think strict rules are the only way to go. Since this
> is
> > a very subjective matter it makes sense to go with something (somewhat)
> > well
> > established like the Google code style.
> >
>

[aalexandrov]

+1 for not limiting the line length.

2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:

> +1 for not limiting the line length. Everyone should have a good sense to
> break lines. When in exceptional cases people violate this, it is usually
> for a good reason.
>
> On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <[hidden email]>
> wrote:
>
> > +1 for enforcing a more strict Java code style. However, let's not
> > introduce a line legth of 100 like in Scala. I think that's hurting
> > readability of the code.
> >
> > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]> wrote:
> >
> > > On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]>
> > wrote:
> > >
> > > > I'm in favor of strict coding styles. And I like the google style.
> > >
> > >
> > > +1 I would like that. We essentially all agree that we want more
> > > homogeneity and I think strict rules are the only way to go. Since this
> > is
> > > a very subjective matter it makes sense to go with something (somewhat)
> > > well
> > > established like the Google code style.
> > >
> >
>

[Hermann Gábor]

+1 for the stricter Java code styles.

We should not forget about providing code formatter settings for Eclipse
and Intellij IDEA (as mentioned above).
That would help a lot.

(Of course if we'll use Google Code Style, they already provide such files
<https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml>
.)

On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
[hidden email]> wrote:

> +1 for not limiting the line length.
>
> 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
>
> > +1 for not limiting the line length. Everyone should have a good sense to
> > break lines. When in exceptional cases people violate this, it is usually
> > for a good reason.
> >
> > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <[hidden email]>
> > wrote:
> >
> > > +1 for enforcing a more strict Java code style. However, let's not
> > > introduce a line legth of 100 like in Scala. I think that's hurting
> > > readability of the code.
> > >
> > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]> wrote:
> > >
> > > > On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]>
> > > wrote:
> > > >
> > > > > I'm in favor of strict coding styles. And I like the google style.
> > > >
> > > >
> > > > +1 I would like that. We essentially all agree that we want more
> > > > homogeneity and I think strict rules are the only way to go. Since
> this
> > > is
> > > > a very subjective matter it makes sense to go with something
> (somewhat)
> > > > well
> > > > established like the Google code style.
> > > >
> > >
> >
>

[Till Rohrmann]

+1 for stricter Java code styles. I haven't looked into the Google Code
Style but maybe we make it easier for new contributors if we apply a coding
style which is somehow known.

+1 for line length of 100 for Scala code. I think it makes code review on
GitHub easier.

For the Scala style, we could stick to official style guidelines [1].

[1] http://docs.scala-lang.org/style/

On Mon, Mar 16, 2015 at 3:06 PM, Hermann Gábor <[hidden email]> wrote:

> +1 for the stricter Java code styles.
>
> We should not forget about providing code formatter settings for Eclipse
> and Intellij IDEA (as mentioned above).
> That would help a lot.
>
> (Of course if we'll use Google Code Style, they already provide such files
> <
> https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml
> >
> .)
>
> On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
> [hidden email]> wrote:
>
> > +1 for not limiting the line length.
> >
> > 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
> >
> > > +1 for not limiting the line length. Everyone should have a good sense
> to
> > > break lines. When in exceptional cases people violate this, it is
> usually
> > > for a good reason.
> > >
> > > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <[hidden email]>
> > > wrote:
> > >
> > > > +1 for enforcing a more strict Java code style. However, let's not
> > > > introduce a line legth of 100 like in Scala. I think that's hurting
> > > > readability of the code.
> > > >
> > > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]> wrote:
> > > >
> > > > > On Saturday, March 14, 2015, Aljoscha Krettek <[hidden email]
> >
> > > > wrote:
> > > > >
> > > > > > I'm in favor of strict coding styles. And I like the google
> style.
> > > > >
> > > > >
> > > > > +1 I would like that. We essentially all agree that we want more
> > > > > homogeneity and I think strict rules are the only way to go. Since
> > this
> > > > is
> > > > > a very subjective matter it makes sense to go with something
> > (somewhat)
> > > > > well
> > > > > established like the Google code style.
> > > > >
> > > >
> > >
> >
>

[Aljoscha Krettek-2]

I'm already always sticking to the official Scala style guide, with the
exception of 100 line length.
On Mar 16, 2015 3:27 PM, "Till Rohrmann" <[hidden email]> wrote:

> +1 for stricter Java code styles. I haven't looked into the Google Code
> Style but maybe we make it easier for new contributors if we apply a coding
> style which is somehow known.
>
> +1 for line length of 100 for Scala code. I think it makes code review on
> GitHub easier.
>
> For the Scala style, we could stick to official style guidelines [1].
>
> [1] http://docs.scala-lang.org/style/
>
> On Mon, Mar 16, 2015 at 3:06 PM, Hermann Gábor <[hidden email]>
> wrote:
>
> > +1 for the stricter Java code styles.
> >
> > We should not forget about providing code formatter settings for Eclipse
> > and Intellij IDEA (as mentioned above).
> > That would help a lot.
> >
> > (Of course if we'll use Google Code Style, they already provide such
> files
> > <
> >
> https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml
> > >
> > .)
> >
> > On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
> > [hidden email]> wrote:
> >
> > > +1 for not limiting the line length.
> > >
> > > 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
> > >
> > > > +1 for not limiting the line length. Everyone should have a good
> sense
> > to
> > > > break lines. When in exceptional cases people violate this, it is
> > usually
> > > > for a good reason.
> > > >
> > > > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <[hidden email]>
> > > > wrote:
> > > >
> > > > > +1 for enforcing a more strict Java code style. However, let's not
> > > > > introduce a line legth of 100 like in Scala. I think that's hurting
> > > > > readability of the code.
> > > > >
> > > > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]>
> wrote:
> > > > >
> > > > > > On Saturday, March 14, 2015, Aljoscha Krettek <
> [hidden email]
> > >
> > > > > wrote:
> > > > > >
> > > > > > > I'm in favor of strict coding styles. And I like the google
> > style.
> > > > > >
> > > > > >
> > > > > > +1 I would like that. We essentially all agree that we want more
> > > > > > homogeneity and I think strict rules are the only way to go.
> Since
> > > this
> > > > > is
> > > > > > a very subjective matter it makes sense to go with something
> > > (somewhat)
> > > > > > well
> > > > > > established like the Google code style.
> > > > > >
> > > > >
> > > >
> > >
> >
>

[Till Rohrmann]

Do we already enforce the official Scala style guide strictly?

On Mon, Mar 16, 2015 at 4:57 PM, Aljoscha Krettek <[hidden email]>
wrote:

> I'm already always sticking to the official Scala style guide, with the
> exception of 100 line length.
> On Mar 16, 2015 3:27 PM, "Till Rohrmann" <[hidden email]> wrote:
>
> > +1 for stricter Java code styles. I haven't looked into the Google Code
> > Style but maybe we make it easier for new contributors if we apply a
> coding
> > style which is somehow known.
> >
> > +1 for line length of 100 for Scala code. I think it makes code review on
> > GitHub easier.
> >
> > For the Scala style, we could stick to official style guidelines [1].
> >
> > [1] http://docs.scala-lang.org/style/
> >
> > On Mon, Mar 16, 2015 at 3:06 PM, Hermann Gábor <[hidden email]>
> > wrote:
> >
> > > +1 for the stricter Java code styles.
> > >
> > > We should not forget about providing code formatter settings for
> Eclipse
> > > and Intellij IDEA (as mentioned above).
> > > That would help a lot.
> > >
> > > (Of course if we'll use Google Code Style, they already provide such
> > files
> > > <
> > >
> >
> https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml
> > > >
> > > .)
> > >
> > > On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
> > > [hidden email]> wrote:
> > >
> > > > +1 for not limiting the line length.
> > > >
> > > > 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
> > > >
> > > > > +1 for not limiting the line length. Everyone should have a good
> > sense
> > > to
> > > > > break lines. When in exceptional cases people violate this, it is
> > > usually
> > > > > for a good reason.
> > > > >
> > > > > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <
> [hidden email]>
> > > > > wrote:
> > > > >
> > > > > > +1 for enforcing a more strict Java code style. However, let's
> not
> > > > > > introduce a line legth of 100 like in Scala. I think that's
> hurting
> > > > > > readability of the code.
> > > > > >
> > > > > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]>
> > wrote:
> > > > > >
> > > > > > > On Saturday, March 14, 2015, Aljoscha Krettek <
> > [hidden email]
> > > >
> > > > > > wrote:
> > > > > > >
> > > > > > > > I'm in favor of strict coding styles. And I like the google
> > > style.
> > > > > > >
> > > > > > >
> > > > > > > +1 I would like that. We essentially all agree that we want
> more
> > > > > > > homogeneity and I think strict rules are the only way to go.
> > Since
> > > > this
> > > > > > is
> > > > > > > a very subjective matter it makes sense to go with something
> > > > (somewhat)
> > > > > > > well
> > > > > > > established like the Google code style.
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

[Aljoscha Krettek-2]

No, but I don't know whether that's possible.

The style guide prescribes, for example, this:

def foo(
  a: Int,
  b: String,
  c: String)

for methods with long parameter lists while a lot of people do this:

def foo(a: Int,
            b: String,
            c: String)

(IntelliJ also does this).

The scalastyle rules I added supposedly check for the official scala
guide style but they allow both styles of methods.

On Mon, Mar 16, 2015 at 5:37 PM, Till Rohrmann <[hidden email]> wrote:

> Do we already enforce the official Scala style guide strictly?
>
> On Mon, Mar 16, 2015 at 4:57 PM, Aljoscha Krettek <[hidden email]>
> wrote:
>
>> I'm already always sticking to the official Scala style guide, with the
>> exception of 100 line length.
>> On Mar 16, 2015 3:27 PM, "Till Rohrmann" <[hidden email]> wrote:
>>
>> > +1 for stricter Java code styles. I haven't looked into the Google Code
>> > Style but maybe we make it easier for new contributors if we apply a
>> coding
>> > style which is somehow known.
>> >
>> > +1 for line length of 100 for Scala code. I think it makes code review on
>> > GitHub easier.
>> >
>> > For the Scala style, we could stick to official style guidelines [1].
>> >
>> > [1] http://docs.scala-lang.org/style/
>> >
>> > On Mon, Mar 16, 2015 at 3:06 PM, Hermann Gábor <[hidden email]>
>> > wrote:
>> >
>> > > +1 for the stricter Java code styles.
>> > >
>> > > We should not forget about providing code formatter settings for
>> Eclipse
>> > > and Intellij IDEA (as mentioned above).
>> > > That would help a lot.
>> > >
>> > > (Of course if we'll use Google Code Style, they already provide such
>> > files
>> > > <
>> > >
>> >
>> https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml
>> > > >
>> > > .)
>> > >
>> > > On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
>> > > [hidden email]> wrote:
>> > >
>> > > > +1 for not limiting the line length.
>> > > >
>> > > > 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
>> > > >
>> > > > > +1 for not limiting the line length. Everyone should have a good
>> > sense
>> > > to
>> > > > > break lines. When in exceptional cases people violate this, it is
>> > > usually
>> > > > > for a good reason.
>> > > > >
>> > > > > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <
>> [hidden email]>
>> > > > > wrote:
>> > > > >
>> > > > > > +1 for enforcing a more strict Java code style. However, let's
>> not
>> > > > > > introduce a line legth of 100 like in Scala. I think that's
>> hurting
>> > > > > > readability of the code.
>> > > > > >
>> > > > > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]>
>> > wrote:
>> > > > > >
>> > > > > > > On Saturday, March 14, 2015, Aljoscha Krettek <
>> > [hidden email]
>> > > >
>> > > > > > wrote:
>> > > > > > >
>> > > > > > > > I'm in favor of strict coding styles. And I like the google
>> > > style.
>> > > > > > >
>> > > > > > >
>> > > > > > > +1 I would like that. We essentially all agree that we want
>> more
>> > > > > > > homogeneity and I think strict rules are the only way to go.
>> > Since
>> > > > this
>> > > > > > is
>> > > > > > > a very subjective matter it makes sense to go with something
>> > > > (somewhat)
>> > > > > > > well
>> > > > > > > established like the Google code style.
>> > > > > > >
>> > > > > >
>> > > > >
>> > > >
>> > >
>> >
>>

[Fabian Hueske-2]

Touching every file of the code would also be a good opportunity to switch
from tab to space indention.
So if we enforce a strict style, we could also address this issue which
causes discussions every now and then.

2015-03-16 21:53 GMT+01:00 Aljoscha Krettek <[hidden email]>:

> No, but I don't know whether that's possible.
>
> The style guide prescribes, for example, this:
>
> def foo(
>   a: Int,
>   b: String,
>   c: String)
>
> for methods with long parameter lists while a lot of people do this:
>
> def foo(a: Int,
>             b: String,
>             c: String)
>
> (IntelliJ also does this).
>
> The scalastyle rules I added supposedly check for the official scala
> guide style but they allow both styles of methods.
>
> On Mon, Mar 16, 2015 at 5:37 PM, Till Rohrmann <[hidden email]>
> wrote:
> > Do we already enforce the official Scala style guide strictly?
> >
> > On Mon, Mar 16, 2015 at 4:57 PM, Aljoscha Krettek <[hidden email]>
> > wrote:
> >
> >> I'm already always sticking to the official Scala style guide, with the
> >> exception of 100 line length.
> >> On Mar 16, 2015 3:27 PM, "Till Rohrmann" <[hidden email]> wrote:
> >>
> >> > +1 for stricter Java code styles. I haven't looked into the Google
> Code
> >> > Style but maybe we make it easier for new contributors if we apply a
> >> coding
> >> > style which is somehow known.
> >> >
> >> > +1 for line length of 100 for Scala code. I think it makes code
> review on
> >> > GitHub easier.
> >> >
> >> > For the Scala style, we could stick to official style guidelines [1].
> >> >
> >> > [1] http://docs.scala-lang.org/style/
> >> >
> >> > On Mon, Mar 16, 2015 at 3:06 PM, Hermann Gábor <[hidden email]>
> >> > wrote:
> >> >
> >> > > +1 for the stricter Java code styles.
> >> > >
> >> > > We should not forget about providing code formatter settings for
> >> Eclipse
> >> > > and Intellij IDEA (as mentioned above).
> >> > > That would help a lot.
> >> > >
> >> > > (Of course if we'll use Google Code Style, they already provide such
> >> > files
> >> > > <
> >> > >
> >> >
> >>
> https://code.google.com/p/google-styleguide/source/browse/trunk/intellij-java-google-style.xml
> >> > > >
> >> > > .)
> >> > >
> >> > > On Mon, Mar 16, 2015 at 2:45 PM Alexander Alexandrov <
> >> > > [hidden email]> wrote:
> >> > >
> >> > > > +1 for not limiting the line length.
> >> > > >
> >> > > > 2015-03-16 14:39 GMT+01:00 Stephan Ewen <[hidden email]>:
> >> > > >
> >> > > > > +1 for not limiting the line length. Everyone should have a good
> >> > sense
> >> > > to
> >> > > > > break lines. When in exceptional cases people violate this, it
> is
> >> > > usually
> >> > > > > for a good reason.
> >> > > > >
> >> > > > > On Mon, Mar 16, 2015 at 2:18 PM, Maximilian Michels <
> >> [hidden email]>
> >> > > > > wrote:
> >> > > > >
> >> > > > > > +1 for enforcing a more strict Java code style. However, let's
> >> not
> >> > > > > > introduce a line legth of 100 like in Scala. I think that's
> >> hurting
> >> > > > > > readability of the code.
> >> > > > > >
> >> > > > > > On Sat, Mar 14, 2015 at 4:41 PM, Ufuk Celebi <[hidden email]>
> >> > wrote:
> >> > > > > >
> >> > > > > > > On Saturday, March 14, 2015, Aljoscha Krettek <
> >> > [hidden email]
> >> > > >
> >> > > > > > wrote:
> >> > > > > > >
> >> > > > > > > > I'm in favor of strict coding styles. And I like the
> google
> >> > > style.
> >> > > > > > >
> >> > > > > > >
> >> > > > > > > +1 I would like that. We essentially all agree that we want
> >> more
> >> > > > > > > homogeneity and I think strict rules are the only way to go.
> >> > Since
> >> > > > this
> >> > > > > > is
> >> > > > > > > a very subjective matter it makes sense to go with something
> >> > > > (somewhat)
> >> > > > > > > well
> >> > > > > > > established like the Google code style.
> >> > > > > > >
> >> > > > > >
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
>