I created a basic Scala Dotty project using Dotty template and import the project to IntelliJ IDE.
Everything works fine when I use the sbt command line.
When I try to build or run it inside IntelliJ IDE, I got following errors:
Error:scalac: Multiple 'scala-library*.jar' files (scala-library-0.9.0-RC1.jar, scala-library-2.12.6.jar) in Scala compiler classpath in Scala SDK sbt: ch.epfl.lamp:dotty-library_0.9:0.9.0-RC1:jar
Any ideas how to solve this?
IDE support for Dotty
Currently, the only IDE we officially support is Visual Studio Code.
Anyway when you import a project to IntelliJ IDEA check "use sbt shell". At least for me after that a test project compiles and runs with Ctrl+Shift+F10.
It's possible that not everything will work. For example Dotty macros don't but if I compile and run manually then they do.
Related
Using the Cats library for Scala in IntelliJ IDEA leads to errors even if terminal SBT works. Can we fix this? Or some workaround that isn't switching editor?
Cats seems to work fine on my IntelliJ 2018.1.4. If it is working in the terminal but not in IntelliJ, it could be because of using in-built IntelliJ compiler. Have you tried enabling Use sbt shell for build and import, which delegates building to SBT:
Open sbt projects tool window: View | Tool Windows | sbt
Click sbt settings icon
Select Use sbt shell for build and import (required sbt 0.13.5+)
Use sbt shell might resolve compilation issues, however note that in-editor error highlighting might still give false positives because it uses custom-built typechecker.
Metals is an alternative that uses Scala proper for both compilation and in-editor error diagnostics.
As shown in the picture, when I build scala project with sbteclipse and import to eclipse, when changing build.sbt , jars are downloaded to my computer but not to scalaProject. I do not know why. Can someone help me?
scala version: 2.11.8
sbt version: 0.13.15
stbeclipse:5.1.0
I assume that you're using the Scala IDE plugin for Eclipse, correct?
The sbteclipse SBT plugin merely provides a command to generate an Eclipse Scala project from the SBT build. Before using Eclipse, you're supposed to issue the following command (from the command line) to SBT:
sbt eclipse
This should generate the project files for your Eclipse project. After executing this command, you can open your project using Eclipse (with the Scala IDE plugin).
Note that, at present, the Scala IDE Eclipse plugin does not support SBT build files. That is, if you change your SBT build file, then Eclipse will be none the wiser, until you re-run the above command.
You might want to consider switching to IntelliJ IDEA (instead of Eclipse) which has a full-featured Scala plugin that fully supports SBT builds, including downloading any dependencies. For my money (both IDEs are free) IntelliJ is light-years ahead of Eclipse for Scala development.
I have to do some assignments with Scala and I'm a newbie for this language.
In the assignment, the prof requests me to implement serialization and deserialization, using twitter/chill.
https://github.com/twitter/chill/
However, I don't know how to import the libary into my IDE Intellij.
Each time I use val instantiator = new ScalaKryoInstantiator.
IDE notify me that: Cannot resolve symbol ScalaKryoInstantiator.
Could anyone can help me to resolve this issue?
Thanks and Best Regards,
Long.
One way to add a library in a Scala project, if you use sbt, is to add an sbt dependency. Most libraries and jars can be found and downloaded from the maven repositories: https://mvnrepository.com/artifact/com.twitter/chill_2.9.2/0.2.3
If you click the sbt tab on the page above, maven gives you a code snippet which can be directly pasted into your build.sbt. In order to compile and run your project using sbt, open the terminal in the directory where your build.sbt is located and use the "sbt run" command.
If you don't use sbt, download the jar from maven and follow the instructions in this answer: How to add external library in IntelliJ IDEA?
I have the Scala and SBT plugins enabled (I tried switching off the SBT plugin as well to test) - when I import an existing Play framework project, go to "Project Structure", go to "Modules", select module, then "Dependencies" tab - I do not see the Scala Compiler library options at all over there (I have JDK8 and it is selected as the IDE project JVM and I have Scala and SBT on the computer - Scala v2.11.7 & SBT v0.13.9). Any ideas on what I might be missing? I only see the JDK and Module source under Dependencies but no Scala compiler options.
I am familiar with the IntelliJ blog referencing how to import a play framework project: https://www.jetbrains.com/idea/help/getting-started-with-play-2-x.html
I am only showing the scala sdk in my Global Libraries tab in Project Structure.
Are you not able to build your project in IntelliJ?
I'm trying to develop on the Scala compiler project with the help of ScalaIDE. I followed this guide to set up the development environment. When I now try to build the mentioned projects, the reflect project won't get built. Instead, I get the following error via the console output:
uncaught exception during compilation: scala.reflect.internal.MissingRequirementError reflect Unknown Scala Problem
Having tried the provided ANT script of the project via the console, everything seems to work fine.
Does anyone know if I'm missing a hidden compiler flag, dependency or something like this?
Thanks!
With the IDE for Scala 2.10 you can only build the 2.10.x branch of the Scala compiler. If you want to work on master, you need to install a 2.11-based version of the IDE. We don't publicise IDE for 2.11 nightlies yet, but they are available at:
http://download.scala-ide.org/nightly/scala-ide-master-2.11.0-SNAPSHOT/