Update to Scala 2.12.0

This updates to Scala 2.12.0. Script engine support has been refactored
since the last scripting-scala release. See this commit:
scala/scala@3cddeaa

No longer requires binding of attribute names with type (e.g. name: Type)
to get typed values. Thus we no longer need to override ScriptEngine
methods.

Signed-off-by: Curtis Rueden <ctrueden@wisc.edu>

Author: keithschulze

pom.xml

@@ -64,7 +64,7 @@
 
 	<properties>
 		<scijava.jvm.version>1.8</scijava.jvm.version>
-		<scala.version>2.12.0-M4</scala.version>
+		<scala.version>2.12.0</scala.version>
 	</properties>
 
 	<dependencies>

src/main/java/org/scijava/plugins/scripting/scala/ScalaScriptEngine.java

@@ -30,12 +30,21 @@
 
 package org.scijava.plugins.scripting.scala;
 
+import java.net.URLClassLoader;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
 import javax.script.ScriptEngine;
 
 import org.scijava.plugin.Plugin;
 import org.scijava.script.AdaptedScriptLanguage;
 import org.scijava.script.ScriptLanguage;
 
+import scala.tools.nsc.ConsoleWriter;
+import scala.tools.nsc.NewLinePrintWriter;
+import scala.tools.nsc.Settings;
+import scala.tools.nsc.interpreter.Scripted;
+
 /**
  * An adapter of the Scala interpreter to the SciJava scripting interface.
  * 
@@ -52,6 +61,20 @@ public ScalaScriptLanguage() {
 
 	@Override
 	public ScriptEngine getScriptEngine() {
-		return new ScalaScriptEngine(super.getScriptEngine());
+		final Settings settings = new Settings();
+		settings.classpath().value_$eq(getClasspath());
+
+		return Scripted.apply(new Scripted.Factory(), settings,
+			new NewLinePrintWriter(new ConsoleWriter(), true));
+	}
+
+	/**
+	 * Uses ClassLoader to generate a string of the current classpath separated by
+	 * OS specific separator.
+	 */
+	private static String getClasspath() {
+		return Arrays.stream(((URLClassLoader) ClassLoader.getSystemClassLoader())
+			.getURLs()).map(url -> url.getPath()).collect(Collectors.joining(System
+				.getProperty("path.separator")));
 	}
 }

src/main/java/org/scijava/plugins/scripting/scala/ScalaScriptLanguage.java

@@ -35,6 +35,7 @@
 import java.io.StringWriter;
 
 import javax.script.ScriptEngine;
+import javax.script.SimpleScriptContext;
 
 import org.junit.Test;
 import org.scijava.Context;
@@ -57,11 +58,12 @@ public void testBasic() throws Exception {
 			scriptService.getLanguageByExtension("scala");
 		final ScriptEngine engine = language.getScriptEngine();
 
+		final SimpleScriptContext ssc = new SimpleScriptContext();
 		final StringWriter writer = new StringWriter();
-		engine.put("writer", writer);
+		ssc.setWriter(writer);
 
-		final String script = "writer.write(\"3\");";
-		engine.eval(script);
+		final String script = "print(\"3\");";
+		engine.eval(script, ssc);
 		assertEquals("3", writer.toString());
 	}
 }