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  • 04:15
    SethTisue edited #1405
  • 04:15

    SethTisue on 2.12.x

    2.12: new Scala SHA (#1405) (compare)

  • 04:15
    SethTisue closed #1405
  • 02:05
    scala-jenkins milestoned #9618
  • 02:05
    eltociear opened #9618
  • May 07 21:50
    neko-kai commented #9605
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    neko-kai commented #9614
  • May 07 18:00
    smarter commented #9605
  • May 07 17:57
    neko-kai commented #9605
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    neko-kai commented #9605
  • May 07 17:56
    neko-kai commented #9605
  • May 07 17:56
    neko-kai commented #9605
  • May 07 17:50
    smarter commented #9605
  • May 07 17:47
    neko-kai commented #9605
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    neko-kai commented #9605
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    neko-kai commented #9605
  • May 07 17:41
    smarter commented #9605
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  • May 07 17:30
    SethTisue labeled #12391
  • May 07 17:30
    neko-kai commented #9605
arunsumbria
@arunsumbria
hi i am new to spark, i installed spark on windows 10 , when using below command its showing path dosent exist, i have winutils too under c drive
 val df = spark.read.csv("file:///C:/spark/myprog/emp")
org.apache.spark.sql.AnalysisException: Path does not exist: file:/C:/spark/myprog/emp;
i have provided 777 permission to c:\tmp\hive
vijendra singh
@viju0731_twitter
How do i call object from parent class to child class
?
aby idea. i know how to call methods but when i am trying same way for object objectname extends
it is not working for me
Rob Norris
@tpolecat
can you create a minimal example that demonstrates what you're trying to do?
Dominic Egger
@GrafBlutwurst
Hi everyone. So I have a REST API that guarantees idempotence and I want to do a local trivial fixed size cache. what's the smartest way to keep this RT? State?
Fabio Labella
@SystemFw
@GrafBlutwurst Ref + IO
possibly behind a final tagless api to not expose implementation details
State can't deal with concurrent state, so you can't do (most types of) caching with it
Dominic Egger
@GrafBlutwurst
yeah that's what I'm doing anyway I don't want to expose the caching to external user except size
ah I see
<3 looks exactly like what I needed thanks!
Fabio Labella
@SystemFw
let me know if you're having problems encoding the logic you need there, but generally fs2.Ref + fs2.Promise (now cats.effect.Ref and cats.effect.Deferred) are your friends
moritz bust
@busti
Is there a way to automatically create a companion object for a class?
ndv87
@ndv87
@Busti in IDEA u can Alt+Insert -> Comp obj
moritz bust
@busti
That is a nice idea, but I am thinking more about a code thing here...
What I am trying to do is to implicitly create a companion object for every child of a class. Since it always has the same members, there is no need to re-write it every time that class is extended.
But I guess that could only be solved by codegen, which might not be that good of an idea.
Dominic Egger
@GrafBlutwurst
@SystemFw this does this seem sensible?
I'll only have to do a fixed size alternative to Map and evict LRU style when adding
maybe just use Chris' scalacache
Fabio Labella
@SystemFw
@GrafBlutwurst there's a problem with that
you are creating new Ref and HttpClient every time
with the Client, it's just wasteful
with the Ref, it won't work because you aren't sharing the state
Dominic Egger
@GrafBlutwurst
lazyness?
Fabio Labella
@SystemFw
nope, purity
if you mention cache, you create a new cache
Dominic Egger
@GrafBlutwurst
oh right. substitution ... derp
Fabio Labella
@SystemFw
if you want to share the state, you need to pass it as an argument and flatMap everytime
this is a feature because it means that the region of state sharing is the same as your call graph
but you need to get used to it
in caching terms, caches always reduce to having type IO[IO[A]], and not IO[A]
Dominic Egger
@GrafBlutwurst
so i necessarily need to expose my state outside?
Fabio Labella
@SystemFw

in this case if you have

trait Cache[F[_], A] {
   def get: F[A]
}

then the constructor needs to be

object Cache {
  def create: F[Cache[F, A]] = ....
no, you don't have to expose the state, but you will have F[Cache[F,
and for that the same argument applies, you need to pass the cache wherever it's needed, and then create it and flatMap it once at the end of the region of sharing you want to create, e.g. main if your whole app needs it
you can always unsafeRunSync it if you want a truly global one but I'd discourage that
I'd rather be in full control of who shares what state
Vasco Dias
@vascorsd
Hi, is there other ways to define the jvm flags required for scala to compile when using sbt (specifically the Xss)? I' using the $JVM_OPTS environment var. I see it could be maybe also on $SBT_OPTS or any of the opts files that sbt also runs. I'm wondering because I have a colleague saying it should go inside the build.sbt file directly and stay defined there... looking for a good reason and/or argument why it shouldn't.
Fabio Labella
@SystemFw
The same argument goes for the HttpClient (and for all stateful things actually)
Dominic Egger
@GrafBlutwurst
so my ioSchemaRegistry not only needs a URL but also a cache passed?
Fabio Labella
@SystemFw
nope
the code that uses ioSchemaRegistry needs to be passed ioSchemaRegistry
because ioSchemaRegistry will return IO[SchemaRegistry[IO]]
Dominic Egger
@GrafBlutwurst
I need a moment to wrap my head around this
Fabio Labella
@SystemFw
and so the same argument applies, if you flatMap twice you get two different caches, and you create two different regions of state sharing