configure ant for scala

Question

How do I install the antlib.xml for scala to get ant working?

Right now I encounter the following error when I run ant on a build.xml file that contains

Answer 1

The antlib.xml is contained in the scala-compiler.jar. You have to put it into your classpath. To define the scalacant task, put the following definition into your ant build file (this is taken form http://www.scala-lang.org/node/98):

<target name="init">
  <property
    name="scala-library.jar"
    value="${scala.home}/lib/scala-library.jar"
     />
  <path id="build.classpath">
    <pathelement location="${scala-library.jar}"   />
    <!--<pathelement location="${your.path}"   />-->
    <pathelement location="${build.dir}"   />
  </path>
  <taskdef resource="scala/tools/ant/antlib.xml">
    <classpath>
      <pathelement location="${scala.home}/lib/scala-compiler.jar"   />
      <!-- NEW: For scala 2.10.2 you need scala-reflect: -->
      <pathelement location="${scala.home}/lib/scala-reflect.jar"   />
      <pathelement location="${scala-library.jar}"   />
    </classpath>
  </taskdef>
</target>

To use the scalac task, add the attribute depends="init" to your task, e.g.

<target name="compile" depends="init">
  <mkdir dir="${build.dir}"/>

  <scalac srcdir="${src.dir}" destdir="${build.dir}"
          classpathref="project.classpath" force="changed">
          <!-- addparams="-Yclosure-elim -optimise" -->
    <include name="**/*.scala"/>
  </scalac>
</target>

I hope, that helps.