Hi! I think this no Scala version issue, you probably miss an import statement:
"import org.apache.flink.streaming.api.scala._" or "import org.apache.flink.api.scala._" See also here: http://flink.apache.org/faq.html#in-scala-api-i-get-an-error-about-implicit-values-and-evidence-parameters Greetings, Stephan On Sat, Jan 16, 2016 at 9:09 PM, Prez Cannady <revp...@opencorrelate.org> wrote: > Attempting to get settled with Flink under Scala 2.11, but running into > some odd issues with macro expansion in a project that depends on > flink-scala_2.11 and flink-runtime_211. > > I’ve instrumented the SocketStreamWordCount quick start < > https://github.com/OCExercise/wordcount-processing> to test this issue. > It depends on Flink 1.0-SNAPSHOT, so you can test against a local build of > Flink for 2.11. > > Steps taken > > Cloned source and checked out release-0.1 > Ran tools/change-scala-version.sh 2.11 > Ran mvn clean install -Dscala.version=2.11.4 -Dscala.binary.version=2.11 > -Dakka.version=2.4.1 -DskipTests=true at Flink root; build succeeds > Ran my spring-booted downstream project’s build and boot run. > Expected result > > Success > > Actual result > > During compilation, I get the following error: > > [ERROR] > /Users/revprez/dev/exercise/systems/jvm/flink/wordcount-processing/src/main/scala/org/opencorrelate/jvm/scala/SocketTextStreamWordCount.scala:73: > error: could not find implicit value for evidence parameter of type > org.apache.flink.api.common.typeinfo.TypeInformation[String] > [ERROR] val counts = text.flatMap { _.toLowerCase.split("\\W+") > filter { _.nonEmpty } } > [ERROR] ^ > [ERROR] > /Users/revprez/dev/exercise/systems/jvm/flink/wordcount-processing/src/main/scala/org/opencorrelate/jvm/scala/WordCount.scala:40: > error: can't expand macros compiled by previous versions of Scala > [ERROR] val text = env.fromElements("To be, or not to be,--that is the > question:--", > > > Discussion > > I’m not sure how the Maven build actually succeeded, as there doesn’t seem > to be any quasiquotes_2.11 under org.scalamacros < > http://central.maven.org/maven2/org/scalamacros/> of any version in the > public repos, nor in the four vendor repos configured in flink-parent’s > pom.xml. Unless I’m missing something, > > <dependencies> > <dependency> > <groupId>org.scalamacros</groupId> > > <artifactId>quasiquotes_${scala.binary.version}</artifactId> > <version>${scala.macros.version}</version> > </dependency> > </dependencies> > > > I recall an earlier discussion about issues with 2.10 stuff polluting the > 2.11 build. Not sure if this is related–I’m able to get through everything > I’ve identified up to this point by simply overriding properties in > flunk-parent with command line arguments. > > Also not sure what next steps to take. Don’t know enough about Scala > Macros to know if substituting, say, org.scalameta:quasiquotes_2.11:0.0.4 > is a viable option (actually tried it, seems to be more trouble than it’s > worth). > > If anyone has any ideas, I’m more than willing to try thing—Flink’s on our > critical path and if we can get it operational under 2.11 then we’er golden. > > > > Prez Cannady > p: 617 500 3378 > e: revp...@opencorrelate.org <mailto:revp...@opencorrelate.org> > GH: https://github.com/opencorrelate <https://github.com/opencorrelate> > LI: https://www.linkedin.com/in/revprez < > https://www.linkedin.com/in/revprez> > > > > > > > > > >
