README.md

Jascal Scripting Engine

Jascal is an implementation of JAVA JSR 223 for the Pascal Language. The engine uses the Free-Pascal compiler for the JVM. It is tested on Windows and Linux. It implements the Compilable interface. The support for the Invokable interface is planned in a future. The Engine support passing ScriptEngine.ARGV to the context and bindings.

Unlinke the standard FPC for JVM, Jascal supports the write/writeln instructions, "ParamStr(i:integer) : String" function and has the "ParamCount : integer" variable. To achieve this result a slight transformation of the code is done before compilation. The following code is injected before compilation.

		program {$program_name$};

		{ %VERSION=1.1 }
		{$namespace com.darrylsite.jascal.fpc}

		 {$mode objfpc}
		 {$modeswitch unicodestrings}
		 {$h+}

		uses
		 jdk15, scriptingstream;

		type
		  qprinttype = int64;

		  var
		        usedErrPutStream : JIWriter;
			    programStream : OFRScriptingStreams;
		        commandLine : OFRCommandLine;
		        ParamCount : integer;
		        {$binding_vars$}

		procedure initProgram(argv: Arr1JLString);
		begin
		 programStream :=  OFRScriptingStreams.create(); 
		 commandLine :=  OFRCommandLine.create(argv);
			ParamCount :=  commandLine.getParamCount();
		end;

		function ParamStr(i: integer): JLString;
		begin
			result := commandLine.getParamter(i);
		 end;

		procedure setOutPut(outPut: JIWriter);
		 Begin
		 programStream.setWriter(outPut);
		end;

		procedure setInPut(inPut: JIReader);
		Begin
			 programStream.setReader(inPut);
		 end;

		procedure setErrPut(errPut: JIWriter);
		Begin
		 usedErrPutStream := errPut;
		 end;

Demo

An online Pascal Compiler built on Jascal Scripting Engine is available at http://jascal.darrylsite.com

Usage

To use Jascal, add the JAR file in your project classPath. An example of a JAVA code using Jascal is given bellow. The full code is available in the unit test.

    ScriptEngineManager scriptManager = new ScriptEngineManager();
    ScriptEngine jascal = scriptManager.getEngineByName("Jascal");

    jascal.getContext().setWriter(new OutputStreamWriter(System.out));
    //String[] argv = new String[]{"1458796"};
    //jascal.put(ScriptEngine.ARGV, argv);
    jascal.put("nombre", "1478523699852"); //Binding, it initializes a global variable declared in the pascal code
    jascal.put("nombreTxt", null); //binding for getting the result value

    Compilable CompilableEngine = (Compilable) jascal;
    CompiledScript scriptCompile = CompilableEngine.compile(getScriptFile());

    scriptCompile.eval();
    

    //jascal.getContext().getWriter().flush();