smcscalagenerator.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

//
// The contents of this file are subject to the Mozilla Public
// License Version 1.1 (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy
// of the License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an
// "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
// implied. See the License for the specific language governing
// rights and limitations under the License.
//
// The Original Code is State Machine Compiler (SMC).
//
// The Initial Developer of the Original Code is Charles W. Rapp.
// Portions created by Charles W. Rapp are
// Copyright (C) 2005 - 2007. Charles W. Rapp.
// All Rights Reserved.
//
// Port to Scala by Francois Perrad, [e-mail]
// Copyright 2008, Francois Perrad.
// All Rights Reserved.
//
// Contributor(s):
//   Eitan Suez contributed examples/Ant.
//   (Name withheld) contributed the C# code generation and
//   examples/C#.
//   Francois Perrad contributed the Python code generation and
//   examples/Python, Perl code generation and examples/Perl,
//   Ruby code generation and examples/Ruby, Lua code generation
//   and examples/Lua.
//   Chris Liscio contributed the Objective-C code generation
//   and examples/ObjC.
//
// RCS ID
// $Id: SmcScalaGenerator.java,v 1.4 2008/03/21 14:03:17 fperrad Exp $
//
// CHANGE LOG
// (See the bottom of this file.)
//

package net.sf.smc;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Visits the abstract syntax tree, emitting Scala code.
 * @see SmcElement
 * @see SmcCodeGenerator
 * @see SmcVisitor
 *
 * @author Francois Perrad
 */

public final class SmcScalaGenerator
    extends SmcCodeGenerator
{
//---------------------------------------------------------------
// Member methods
//

    public SmcScalaGenerator(String srcfileBase)
    {
        super (srcfileBase, "{0}{1}Context.{2}", "scala");
    } // end of SmcScalaGenerator(String)

    public void visit(SmcFSM fsm)
    {
        String rawSource = fsm.getSource();
        String packageName = fsm.getPackage();
        String context = fsm.getContext();
        String startState = fsm.getStartState();
        List<SmcMap> maps = fsm.getMaps();
        List<SmcTransition> transitions;
        Iterator<SmcParameter> pit;
        String transName;
        String javaState;
        String separator;
        int index;
        List<SmcParameter> params;

        _source.println("// DO NOT EDIT.");
        _source.println(
            "// generated by smc (http://smc.sourceforge.net/)");
        _source.print("// from file : ");
        _source.print(_srcfileBase);
        _source.println(".sm");

        // Dump out the raw source code, if any.
        if (rawSource != null && rawSource.length() > 0)
        {
            _source.println();
            _source.println(rawSource);
        }

        // If a package has been specified, generate the
        // package statement now.
        if (packageName != null && packageName.length() > 0)
        {
            _source.println();
            _source.print("package ");
            _source.println(packageName);
        }

        _source.println();
        if (Smc.isSynchronized() == true)
        {
            _source.println("import scala.concurrent");
            _source.println();
        }
        // Do user-specified imports now.
        for (String imp: fsm.getImports())
        {
            _source.print("import ");
            _source.println(imp);
        }

        _source.println();

        if (Smc.isSerial() == true)
        {
            _source.println("@serializable");
        }

        // The context clas contains all the state classes as
        // inner classes, so generate the context first rather
        // than last.
        _source.print("class ");
        _source.print(context);
        _source.print("Context(owner: ");
        _source.print(context);
        _source.print(") extends statemap.FSMContext[");
        _source.print(context);
        _source.println("State] {");

        _source.println();
        _source.print("    private val _owner: ");
        _source.print(context);
        _source.println(" = owner");
        _source.println();

        // The state name "map::state" must be changed to
        // "map.state".
        if ((index = startState.indexOf("::")) >= 0)
        {
            javaState =
                startState.substring(0, index) +
                "." +
                startState.substring(index + 2);
        }
        else
        {
            javaState = startState;
        }

        _source.print("    setState(");
        _source.print(javaState);
        _source.println(")");

        // Execute the start state's entry actions.
        _source.print("    ");
        _source.print(javaState);
        _source.println(".Entry(this)");

        _source.println();

        // Generate the default transition methods.
        // Get the transition list for the entire FSM.
        transitions = fsm.getTransitions();

        // Generate the transition methods.
        for (SmcTransition trans: transitions)
        {
            if (trans.getName().equals("Default") == false)
            {
                _source.print("    def ");
                _source.print(trans.getName());
                _source.print("(");

                params = trans.getParameters();
                for (pit = params.iterator(), separator = "";
                     pit.hasNext() == true;
                     separator = ", ")
                {
                    _source.print(separator);
                    (pit.next()).accept(this);
                }
                _source.print("): Unit = ");
                // If the -sync flag was specified, then output
                // the "synchronized" keyword.
                if (Smc.isSynchronized() == true)
                {
                    _source.print("synchronized ");
                }
                _source.println("{");

                // Save away the transition name in case it is
                // need in an UndefinedTransitionException.
                _source.print("        _transition = \"");
                _source.print(trans.getName());
                _source.println("\"");

                _source.print("        getState().");
                _source.print(trans.getName());
                _source.print("(this");

                for (pit = params.iterator();
                     pit.hasNext() == true;
                    )
                {
                    _source.print(", ");
                    _source.print((pit.next()).getName());
                }
                _source.println(")");
                _source.println("        _transition = \"\"");

                _source.println("    }");
                _source.println();
            }
        }

        // getOwner() method.
        _source.print("    def getOwner(): ");
        _source.print(context);
        _source.println(" = _owner");
        _source.println();

        // End of context class.
        _source.println("}");
        _source.println();

        if (Smc.isSerial() == true)
        {
            _source.println("@serializable");
        }

        // Declare the base state class.
        _source.print("class ");
        _source.print(context);
        _source.println("State(name: String, id: Int) {");
        _source.println("    private val _name = name");
        _source.println("    private val _id = id");
        _source.println();
        _source.println("    def getName(): String = _name");
        _source.println();
        _source.println("    override def toString(): String = _name");
        _source.println();

        _source.print("    def Entry(context: ");
        _source.print(context);
        _source.println("Context): Unit = {}");
        _source.print("    def Exit(context: ");
        _source.print(context);
        _source.println("Context): Unit = {}");
        _source.println();

        // Generate the default transition definitions.
        for (SmcTransition trans: transitions)
        {
            transName = trans.getName();

            // Don't generate the Default transition here.
            if (transName.equals("Default") == false)
            {
                _source.print("    def ");
                _source.print(transName);
                _source.print("(context: ");
                _source.print(context);
                _source.print("Context");

                for (SmcParameter param: trans.getParameters())
                {
                    _source.print(", ");
                    param.accept(this);
                }

                _source.println("): Unit = {");

                // If this method is reached, that means that
                // this transition was passed to a state which
                // does not define the transition. Call the
                // state's default transition method.
                _source.println("        Default(context)");

                _source.println("    }");
                _source.println();
            }
        }

        // Generate the overall Default transition for all maps.
        _source.print("    def Default(context: ");
        _source.print(context);
        _source.println("Context): Unit = {");

        if (Smc.isDebug() == true)
        {
            _source.println(
                "        if (context.getDebugFlag())");
            _source.println(
                "            context.getDebugStream().println(\"TRANSITION   : Default\")");
            _source.println();
        }

        _source.println(
            "        throw new statemap.TransitionUndefinedException(");
        _source.println(
            "                \"State: \" + context.getState()._name +");
        _source.println(
            "                \", Transition: \" + context.getTransition())");
        _source.println("    }");

        // End of state class.
        _source.println();
        _source.println("}");
        _source.println();

        // Have each map print out its source code now.
        for (SmcMap map: maps)
        {
            map.accept(this);
        }

        return;
    } // end of visit(SmcFSM)

    public void visit(SmcMap map)
    {
        List<SmcTransition> definedDefaultTransitions;
        SmcState defaultState = map.getDefaultState();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        List<SmcState> states = map.getStates();

        // Initialize the default transition list to all the
        // default state's transitions.
        if (defaultState != null)
        {
            definedDefaultTransitions =
                defaultState.getTransitions();
        }
        else
        {
            definedDefaultTransitions =
                new ArrayList<SmcTransition>();
        }

        // Declare the map default state class.
        _source.print("private class ");
        _source.print(mapName);
        _source.print("_Default(name: String, id: Int) extends ");
        _source.print(context);
        _source.println("State(name, id) {");

        // Declare the user-defined default transitions first.
        _indent = "    ";
        for (SmcTransition trans: definedDefaultTransitions)
        {
            trans.accept(this);
        }

        // If -reflect was specified, then generate the
        // _transitions map.
        if (Smc.isReflection() == true)
        {
            List<SmcTransition> allTransitions =
                map.getFSM().getTransitions();
            String transName;
            int transDefinition;

            // Now output the transition collection's
            // initialization.
            _source.println();
            _source.print("    def getTransitions(): Map[String, Int] = Map(");

            // Now place all transition names and states into the
            // map.
            String sep = "";
            for (SmcTransition transition: allTransitions)
            {
                transName = transition.getName();

                // If the transition is defined in this map's
                // default state, then the value is 2.
                if (definedDefaultTransitions.contains(
                        transition) == true)
                {
                    transDefinition = 2;
                }
                // Otherwise the value is 0 - undefined.
                else
                {
                    transDefinition = 0;
                }

                _source.println(sep);
                _source.print("        \"");