smcvbgenerator.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. Charles W. Rapp.
// 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.
//   Chris Liscio contributed the Objective-C code generation
//   and examples/ObjC.
//
// RCS ID
// $Id: SmcVBGenerator.java,v 1.10 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 VB.Net code.
 * @see SmcElement
 * @see SmcCodeGenerator
 * @see SmcVisitor
 *
 * @author <a href="mailto:[e-mail]">Charles Rapp</a>
 */

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

    public SmcVBGenerator(String srcfileBase)
    {
        super (srcfileBase, "{0}{1}_sm.{2}", "vb");
    } // end of SmcVBGenerator(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;
        List<SmcParameter> params;
        Iterator<SmcParameter> pit;
        String transName;
        String vbState;
        String separator;
        int index;
        String indent2;

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

        // If reflection is on, then import the .Net collections
        // package.
        if (Smc.isReflection() == true)
        {
            _source.println("Imports System.Collections");
        }

        // Do user-specified imports now.
        for (String imp: fsm.getImports())
        {
            _source.print("Imports ");
            _source.println(imp);
        }

        // If serialization is on, then import the .Net
        // serialization package.
        if (Smc.isSerial() == true)
        {
            _source.println(
                "Imports System.Runtime.Serialization");
        }
        _source.println();

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

        // If -serial was specified, then prepend the serialize
        // attribute to the class declaration.
        if (Smc.isSerial() == true)
        {
            _source.print(_indent);
            _source.print("<Serializable()> ");
        }

        // Now declare the context class.
        _source.print(_indent);
        _source.print("Public NotInheritable Class ");
        _source.print(context);
        _source.println("Context");
        _source.print(_indent);
        _source.println("    Inherits statemap.FSMContext");

        // If -serial was specified, then we also implement the
        // ISerializable interface.
        if (Smc.isSerial() == true)
        {
            _source.print(_indent);
            _source.println("    Implements ISerializable");
        }

        // Declare the associated application class as a data
        // member.
        _source.println();
        _source.print(_indent);
        _source.println(
            "    '------------------------------------------------------------");
        _source.print(_indent);
        _source.println("    ' Member data");
        _source.print(_indent);
        _source.println("    '");
        _source.print(_indent);
        _source.println();
        _source.print(_indent);
        _source.println(
            "    ' The associated application class instance.");
        _source.print(_indent);
        _source.print("    Private _owner As ");
        _source.println(context);
        _source.println();

        // If serialization is on, then the shared state array
        // must be generated.
        if (Smc.isSerial() == true)
        {
            String mapName;

            _source.print(_indent);
            _source.println(
                "    '------------------------------------------------------------");
            _source.print(_indent);
            _source.println("    ' Shared data");
            _source.print(_indent);
            _source.println("    '");
            _source.println();
            _source.print(_indent);
            _source.print("    ' State instance array. ");
            _source.println("Used to deserialize.");
            _source.print(_indent);
            _source.print(
                "    Private Shared ReadOnly _States() As ");
            _source.print(context);
            _source.println("State = _");
            _source.print(_indent);
            _source.print("        {");

            // For each map, ...
            separator = " _";
            for (SmcMap map: maps)
            {
                mapName = map.getName();

                // and for each map state, ...
                for (SmcState state: map.getStates())
                {
                    // Add its singleton instance to the array.
                    _source.println(separator);
                    _source.print(_indent);
                    _source.print("            ");
                    _source.print(mapName);
                    _source.print(".");
                    _source.print(state.getClassName());

                    separator = ", _";
                }
            }

            _source.println(" _");
            _source.print(_indent);
            _source.println("        }");
            _source.println();
        }

        // Now declare the current state and owner properties.
        _source.print(_indent);
        _source.println(
            "    '------------------------------------------------------------");
        _source.print(_indent);
        _source.println("    ' Properties");
        _source.print(_indent);
        _source.println("    '");
        _source.println();
        _source.print(_indent);
        _source.print("    Public Property State() As ");
        _source.print(context);
        _source.println("State");
        _source.print(_indent);
        _source.println("        Get");
        _source.print(_indent);
        _source.println("            If _state Is Nothing _");
        _source.print(_indent);
        _source.println("            Then");
        _source.print(_indent);
        _source.print("                Throw ");
        _source.println(
            "New statemap.StateUndefinedException()");
        _source.print(_indent);
        _source.println("            End If");
        _source.println();
        _source.print(_indent);
        _source.println("            Return _state");
        _source.print(_indent);
        _source.println("        End Get");
        _source.println();
        _source.print(_indent);
        _source.print("        Set(ByVal state As ");
        _source.print(context);
        _source.println("State)");
        _source.println();
        _source.print(_indent);
        _source.println("            _state = state");
        _source.print(_indent);
        _source.println("        End Set");
        _source.print(_indent);
        _source.println("    End Property");
        _source.println();
        _source.print(_indent);
        _source.print(
            "    Public Property Owner() As ");
        _source.println(context);
        _source.print(_indent);
        _source.println("        Get");
        _source.print(_indent);
        _source.println("            Return _owner");
        _source.print(_indent);
        _source.println("        End Get");
        _source.print(_indent);
        _source.print("        Set(ByVal owner As ");
        _source.print(context);
        _source.println(")");
        _source.println();
        _source.print(_indent);
        _source.println("            If owner Is Nothing _");
        _source.print(_indent);
        _source.println("            Then");
        _source.print(_indent);
        _source.println(
            "                Throw New NullReferenceException");
        _source.print(_indent);
        _source.println("            End If");
        _source.println();
        _source.print(_indent);
        _source.println("            _owner = owner");
        _source.print(_indent);
        _source.println("        End Set");
        _source.print(_indent);
        _source.println("    End Property");
        _source.println();

        // Generate the class member methods, starting with the
        // constructor.
        _source.print(_indent);
        _source.println(
            "    '------------------------------------------------------------");
        _source.print(_indent);
        _source.println("    ' Member methods");
        _source.print(_indent);
        _source.println("    '");
        _source.println();
        _source.print(_indent);
        _source.print("    Public Sub New(ByRef owner As ");
        _source.print(context);
        _source.println(")");
        _source.println();
        _source.print(_indent);
        _source.println("        _owner = owner");

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

        _source.print(_indent);
        _source.print("        _state = ");
        _source.println(vbState);

        // Execute the start state's entry actions.
        _source.print(_indent);
        _source.print("        ");
        _source.print(vbState);
        _source.println(".Entry(Me)");

        _source.print(_indent);
        _source.println("    End Sub");
        _source.println();

        // Generate the transition methods. These methods are all
        // formatted: set transition name, call the current
        // state's transition method, clear the transition name.
        transitions = fsm.getTransitions();
        for (SmcTransition trans: transitions)
        {
            // Ignore the default transition.
            if (trans.getName().equals("Default") == false)
            {
                _source.print(_indent);
                _source.print("    Public Sub ");
                _source.print(trans.getName());
                _source.print("(");

                // Now output the transition's parameters.
                params = trans.getParameters();
                for (pit = params.iterator(), separator = "";
                     pit.hasNext() == true;
                     separator = ", ")
                {
                    _source.print(separator);
                    (pit.next()).accept(this);
                }
                _source.println(")");
                _source.println();

                // If the -sync flag was specified, then output
                // "SyncLock Me" to prevent multiple threads from
                // access this state machine simultaneously.
                if (Smc.isSynchronized() == true)
                {
                    _source.print(_indent);
                    _source.println("        SyncLock Me");