Hi I've been trying to get the presentation compiler to work but I'm getting the following error. Any help regarding this would be appreciated. I've already seen other questions and few projects where it has been implemented but everyone uses the Global.Run which is not being recognized in the REPL. This the code and the error below it. I've installed scala 2.10.3 in windows 8.1
import scala.tools.nsc.{Global,Settings}
import scala.tools.nsc.reporters._
object Test {
def main (args: Array[String]) {
val settings = new Settings;
val global = new Global(settings,new ConsoleReporter(settings));
val compiler = global.Run;
}
}
The error is
Sample.scala:8: error: value Run is not a member of scala.tools.nsc.Global
Try this:
import scala.tools.nsc.{Global,Settings}
import scala.tools.nsc.reporters._
object Test {
def main (args: Array[String]) {
val settings = new Settings
val global = new Global(settings,new ConsoleReporter(settings))
val compiler = new global.Run
}
}
Notice new Run instead of Run. There is no companion object for class Run. Maybe it was there before in earlier scala versions. Checked on Scala v2.10.3. Works in REPL.
Related
I'm trying to defer ScalaJS Linking to runtime, which allows multi-stage compilation to be more flexible and less dependent on sbt.
The setup looks like this:
Instead of using scalajs-sbt plugin, I chose to invoke scalajs-compiler directly as a scala compiler plugin:
scalaCompilerPlugins("org.scala-js:scalajs-compiler_${vs.scalaV}:${vs.scalaJSV}")
This can successfully generate the "sjsir" files under project output directory, but no further.
Use the solution in this post:
Build / Compile latest SalaJS (1.3+) using gradle on a windows machine?
"Linking scala.js yourself" to invoke the linker on all the compiled sjsir files to produce js files, this is my implementation:
in compile-time & runtime dependencies, add scalajs basics and scalajs-linker:
bothImpl("org.scala-js:scalajs-library_${vs.scalaBinaryV}:${vs.scalaJSV}")
bothImpl("org.scala-js:scalajs-linker_${vs.scalaBinaryV}:${vs.scalaJSV}")
bothImpl("org.scala-js:scalajs-dom_${vs.scalaJSSuffix}:2.1.0")
Write the following code:
import org.scalajs.linker.interface.{Report, StandardConfig}
import org.scalajs.linker.{PathIRContainer, PathOutputDirectory, StandardImpl}
import org.scalajs.logging.{Level, ScalaConsoleLogger}
import java.nio.file.{Path, Paths}
import java.util.Collections
import scala.concurrent.duration.Duration
import scala.concurrent.{Await, ExecutionContext}
object JSLinker {
implicit def gec = ExecutionContext.global
def link(classpath: Seq[Path], outputDir: Path): Report = {
val logger = new ScalaConsoleLogger(Level.Warn)
val linkerConfig = StandardConfig() // look at the API of this, lots of options.
val linker = StandardImpl.linker(linkerConfig)
// Same as scalaJSModuleInitializers in sbt, add if needed.
val moduleInitializers = Seq()
val cache = StandardImpl.irFileCache().newCache
val result = PathIRContainer
.fromClasspath(classpath)
.map(_._1)
.flatMap(cache.cached _)
.flatMap(linker.link(_, moduleInitializers, PathOutputDirectory(outputDir), logger))
Await.result(result, Duration.Inf)
}
def linkClasses(outputDir: Path = Paths.get("./")): Report = {
import scala.jdk.CollectionConverters._
val cl = Thread.currentThread().getContextClassLoader
val resources = cl.getResources("")
val rList = Collections.list(resources).asScala.toSeq.map { v =>
Paths.get(v.toURI)
}
link(rList, outputDir)
}
lazy val linkOnce = {
linkClasses()
}
}
The resources detection was successful, all roots containing sjsir are detected:
rList = {$colon$colon#1629} "::" size = 4
0 = {UnixPath#1917} "/home/peng/git-scaffold/scaffold-gradle-kts/build/classes/scala/test"
1 = {UnixPath#1918} "/home/peng/git-scaffold/scaffold-gradle-kts/build/classes/scala/testFixtures"
2 = {UnixPath#1919} "/home/peng/git-scaffold/scaffold-gradle-kts/build/classes/scala/main"
3 = {UnixPath#1920} "/home/peng/git-scaffold/scaffold-gradle-kts/build/resources/main"
But linking still fails:
Fatal error: java.lang.Object is missing
called from core module analyzer
There were linking errors
org.scalajs.linker.interface.LinkingException: There were linking errors
at org.scalajs.linker.frontend.BaseLinker.reportErrors$1(BaseLinker.scala:91)
at org.scalajs.linker.frontend.BaseLinker.$anonfun$analyze$5(BaseLinker.scala:100)
at scala.concurrent.impl.Promise$Transformation.run$$$capture(Promise.scala:467)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala)
at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1402)
at java.util.concurrent.ForkJoinTask.doExec$$$capture(ForkJoinTask.java:289)
at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java)
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:175)
I wonder what this error message entails. Clearly java.lang.Object is not compiled into sjsir. Does this error message make sense? How do I fix it?
Thanks to #sjrd I now have the correct runtime compilation stack. There are 2 problems in my old settings:
It turns out that cl.getResources("") is indeed not able to infer all classpath, so I switch to system property java.class.path, which contains classpaths of all dependencies
moduleInitializers has to be manually set to point to a main method, which will be invoked when the js function is called.
After correcting them, the compilation class becomes:
import org.scalajs.linker.interface.{ModuleInitializer, Report, StandardConfig}
import org.scalajs.linker.{PathIRContainer, PathOutputDirectory, StandardImpl}
import org.scalajs.logging.{Level, ScalaConsoleLogger}
import java.nio.file.{Files, Path, Paths}
import scala.concurrent.duration.Duration
import scala.concurrent.{Await, ExecutionContext, ExecutionContextExecutor}
object JSLinker {
implicit def gec: ExecutionContextExecutor = ExecutionContext.global
val logger = new ScalaConsoleLogger(Level.Info) // TODO: cannot be lazy val, why?
lazy val linkerConf: StandardConfig = {
StandardConfig()
} // look at the API of this, lots of options.
def link(classpath: Seq[Path], outputDir: Path): Report = {
val linker = StandardImpl.linker(linkerConf)
// Same as scalaJSModuleInitializers in sbt, add if needed.
val moduleInitializers = Seq(
ModuleInitializer.mainMethodWithArgs(SlinkyHelloWorld.getClass.getName.stripSuffix("$"), "main")
)
Files.createDirectories(outputDir)
val cache = StandardImpl.irFileCache().newCache
val result = PathIRContainer
.fromClasspath(classpath)
.map(_._1)
.flatMap(cache.cached _)
.flatMap { v =>
linker.link(v, moduleInitializers, PathOutputDirectory(outputDir), logger)
}
Await.result(result, Duration.Inf)
}
def linkClasses(outputDir: Path = Paths.get("./ui/build/js")): Report = {
val rList = getClassPaths
link(rList, outputDir)
}
def getClassPaths: Seq[Path] = {
val str = System.getProperty("java.class.path")
val paths = str.split(':').map { v =>
Paths.get(v)
}
paths
}
lazy val linkOnce: Report = {
val report = linkClasses()
logger.info(
s"""
|=== [Linked] ===
|${report.toString()}
|""".stripMargin
)
report
}
}
This is all it takes to convert sjsir artefacts to a single main.js file.
When I build my sbt project in Intellij I get the following error:
Error:(7, 8) object DfUtils is not a member of package com.naturalint.xspark.common.sparkutils
import com.naturalint.xspark.common.sparkutils.DfUtils
The object is a part of the package and when I ran sbt compile or package or assembly in terminal everything clears fine. When I move the object to a different location in the project it sometimes work for a day and then again gives the error
This is the content of the file:
package com.naturalint.xspark.common.sparkutils
import org.apache.spark.sql._
import scala.reflect._
object DfUtils {
def removeColumnThatAreNotInEncoder[T <: Product : ClassTag: Encoder](dataEntity: Dataset[T]): Dataset[T] = {
val declaredFields: Array[String] = classTag[T].runtimeClass.getDeclaredFields.map(x => x.getName)
val columns: Array[Column] = declaredFields.map(x => new Column(x))
dataEntity.select(columns: _*).as[T]
}
}
Any thoughts?
Thanks
Nir
object Rec extends App {
val outStream = new java.io.ByteArrayOutputStream
{
val out = new java.io.PrintStream(new java.io.BufferedOutputStream(outStream))
}
}
This seemingly simple code causes a compile error:
$ scalac rec.scala
rec.scala:2: error: recursive value out needs type
val outStream = new java.io.ByteArrayOutputStream
^
one error found
But I don't see what is "recursive."
Scala compiler version 2.11.7 -- Copyright 2002-2013, LAMP/EPFL
Background: I was trying to write a unit test on println with Console.withOut
After putting braces where they belong code looks like this:
object Rec extends App {
val outStream = new java.io.ByteArrayOutputStream {
val out = new java.io.PrintStream(new java.io.BufferedOutputStream(outStream))
}
}
and this is how you create object of an anonymous class with a member out that uses the defined object recursively (outStream uses outStream in its definition).
I believe this is what you wanted to do
object Rec extends App {
val outStream = new java.io.ByteArrayOutputStream
val out = new java.io.PrintStream(new java.io.BufferedOutputStream(outStream))
}
If you for some reason need to create another scope, you can use locally
What does Predef.locally do, and how is it different from Predef.identity
You are assigning a value to outStream by invoking stuff to which you pass on the outStream (I marked it in CAPS). Hence the recursion.
object Rec extends App {
val OUTSTREAM = new java.io.ByteArrayOutputStream
{
val out = new java.io.PrintStream(new java.io.BufferedOutputStream(OUTSTREAM))
}
}
I have found an example code for a Scala runtime scripting in answer to Generating a class from string and instantiating it in Scala 2.10, however the code seems to be obsolete for 2.11 - I cannot find any function corresponding to build.setTypeSignature. Even if it worked, the code seems hard to read and follow to me.
How can Scala scripts be compiled and executed in Scala 2.11?
Let us assume I want following:
define several variables (names and values)
compile script
(optional improvement) change variable values
execute script
For simplicity consider following example:
I want to define following variables (programmatically, from the code, not from the script text):
val a = 1
val s = "String"
I want a following script to be compiled and on execution a String value "a is 1, s is String" returned from it:
s"a is $a, s is $s"
How should my functions look like?
def setupVariables() = ???
def compile() = ???
def changeVariables() = ???
def execute() : String = ???
Scala 2.11 adds a JSR-223 scripting engine. It should give you the functionality you are looking for. Just as a reminder, as with all of these sorts of dynamic things, including the example listed in the description above, you will lose type safety. You can see below that the return type is always Object.
Scala REPL Example:
scala> import javax.script.ScriptEngineManager
import javax.script.ScriptEngineManager
scala> val e = new ScriptEngineManager().getEngineByName("scala")
e: javax.script.ScriptEngine = scala.tools.nsc.interpreter.IMain#566776ad
scala> e.put("a", 1)
a: Object = 1
scala> e.put("s", "String")
s: Object = String
scala> e.eval("""s"a is $a, s is $s"""")
res6: Object = a is 1, s is String`
An addition example as an application running under scala 2.11.6:
import javax.script.ScriptEngineManager
object EvalTest{
def main(args: Array[String]){
val e = new ScriptEngineManager().getEngineByName("scala")
e.put("a", 1)
e.put("s", "String")
println(e.eval("""s"a is $a, s is $s""""))
}
}
For this application to work make sure to include the library dependency.
libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value
I am trying out Slick 3.0.0-RC1 and I'm running in to an odd problem.
Such is my code:
import slick.driver.SQLiteDriver.api._
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.Await
import scala.concurrent.duration.Duration
lazy val db = Database.forURL(
url = "jdbc:sqlite:thebase.db",
driver = "org.sqlite.JDBC"
)
case class Issue(id: Option[Int], name: String)
class IssueTable(tag: Tag) extends Table[Issue](tag, "issue"){
def id = column[Int]("issue_id", O.PrimaryKey)
def name = column[String]("name")
def * = (id.?, name) <> (Issue.tupled, Issue.unapply _)
}
val issueQuery = TableQuery[IssueTable]
Await.result(db.run(issueQuery.result), Duration.Inf) // This does not compile
The error is:
"Cannot resolve symbol result"
Reading the docs I can't really see why this should fail. Am I missing something here?
Resolution
szeiger pointed out that this could be a bug in 'IntelliJ's presentation compiler', and that was spot on.
I did hit the same problem and here is what I did to get rid of it:
Updated IntelliJ to version 14.1.3
Used Scala Plugin version 1.5
My scala version is 2.11.6
I hope this helps somebody who might run into the same problem!
If someone is facing a similar issue:
no result method on TableQuery
DOUBLE check whether you have import slick.jdbc.PostgresProfile.api._
This is a regular problem I faced quite often with IntelliJ IDEA .
If using activator, the command - "activator idea" helped me resolve the issue.
It re-created the .idea and IdeaProject.iml files and then re-loaded the project.
I currently use activator-1.3.4
You may try
val result = db.withSession(implicit session => issueQuery.list)