Pnuts User's Guide -> Extension Modules -> Scripting API (JSR 223)

Scripting API (JSR 223)

Embedding Pnuts Engine

Scripting API (JSR 223) allows you to write Java applications that embed a scripting engine and execute user's scripts through a standardized API (javax.script package).

Pnuts engine for JSR223 is ready for use when pnuts.jar and pnuts-jsr223.jar is in your CLASSPATH.

Example 1

import javax.script.*;

public class HelloWorld  {
	public static void main(String[] args) throws Exception {
		//Initiate ScriptEngineManager
		ScriptEngineManager manager = new ScriptEngineManager();

		//Return Pnuts engine by name
		ScriptEngine jsengine = manager.getEngineByName("pnuts");

		//Execute the HelloWorld script
		jsengine.eval(new java.io.FileReader("HelloWorld.pnut"));
	}
}

Example 2

import javax.script.*;

public class CompilableInterface {
	public static void main(String[] args) throws Exception {
		ScriptEngineManager manager = new ScriptEngineManager();
		ScriptEngine pnutsEngine = manager.getEngineByName("pnuts");

		Compilable eng = (Compilable)pnutsEngine;
		CompiledScript scr = eng.compile(new java.io.FileReader("CompilableInterface.pnut"));
		ScriptEngine e = (ScriptEngine)eng;
		
		//set engine scope namespace
		Bindings n = new SimpleBindings();
		e.setBindings(n, ScriptContext.ENGINE_SCOPE);

		//evaluate compiled script
		for (int i=0; i<3; i++) {
			n.put("count", new Integer(i));		
			n.put("currentTime", new Long(System.currentTimeMillis()));
			scr.eval();
		}
	}
}
				

counter = 0

switch (count) {
	case 0: counter = "first time"; break;
	case 1: counter = "second time"; break;
	case 2: counter = "third time";
}
println("\nRun compiled script, the ", counter)
time = date(currentTime)
println("Current time is ", time)

Configuring Pnuts Engine

To configure a Pnuts scripting engine, call Pnuts.setDefault(Properties) method with any of these properties before Pnuts API is loaded.

Property Description Default
pnuts.modules Specifies the modules to be used when the engine is initialized. It should be a comma-separated list. pnuts.tools
pnuts.lang.defaultPnutsImpl Specifies the class of the default Pnuts Implementation object. See 'The pnuts.lang.defaultPnutsImpl Property' for more details. pnuts.compiler.CompilerPnutsImpl
pnuts.lang.defaultConfiguration If a vaild pnuts.lang.Configuration subclass is specified, an instanceof the class is created with the default constructor and it becomes the default Configuration. The system's default
pnuts.compiler.optimize If true is specified, Pnuts compiler generates a little faster code. Instead, line number information is not printed when an error occurs. false
pnuts.compiler.useDynamicProxy If true is specified, method/constructor call is implemented by dynamic proxy class, rather than reflection API. Method/constructor call could be a little faster using with JIT compiler. true
pnuts.package.factory If this property is specified at start up time, the class becomes the default package factory. See pnuts.lang.PackageFactory. The system's default

jrunscript Command

Pnuts interpreter can be used via jrunscript command, if the following JAR files are in an appropriate directory, or specified in an appropriate command-line options. For example, if JDK1.6.0 is installed at d:\jdk1.6.0 and the JAR files are copied to d:\jdk1.6.0\jre\lib\ext\, the following command starts an interactive session of Pnuts. 
C:\> jrunscript -l pnuts

Alternatively, if the JAR files are located as follows,

the following command also starts an interactive session of Pnuts. 
C:\> jrunscript -J-Djava.ext.dirs=%PNUTS_HOME%\lib;%PNUTS_HOME%\modules -l pnuts
If you are using bash, the command can be shortened by defining an alias as follows. 
alias jrunscript='jrunscript "-J-Djava.ext.dirs=d:/pnuts/lib;d:/pnuts/modules"'
Then, Pnuts engine can be used via jrunscript as if the JAR files are in ${JRE}/lib/ext/. 
bash$ jrunscript -q
Language ECMAScript 0 implemention "Mozilla Rhino" @IMPLEMENTATION.VERSION@
Language Pnuts 1.1 implemention "Pnuts" 1.0
bash$ jrunscript -l pnuts
pnuts>
Pnuts User's Guide -> Extension Modules -> Scripting API (JSR 223)