smcrubygenerator.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.
//
// Port to Python by Francois Perrad, [e-mail]
// Copyright 2004, 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.
//   Chris Liscio contributed the Objective-C code generation
//   and examples/ObjC.
//
// RCS ID
// $Id: SmcRubyGenerator.java,v 1.7 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;
import java.util.StringTokenizer;

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

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

    public SmcRubyGenerator(String srcfileBase)
    {
        super (srcfileBase, "{0}{1}_sm.{2}", "rb");
    } // end of SmcRubyGenerator(String)

    public void visit(SmcFSM fsm)
    {
        String packageName = fsm.getPackage();
        String context = fsm.getContext();
        String rawSource = fsm.getSource();
        String startState = fsm.getStartState();
        List<SmcMap> maps = fsm.getMaps();
        List<SmcTransition> transitions;
        List<SmcParameter> params;
        String transName;
        int packageDepth = 0;
        int index;

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

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

        // If a package has been specified, then output that
        // module now. If the package name is "a::b::c", then
        // this must be converted to:
        // module a
        //   module b
        //     module c
        //       ...
        //     end
        //   end
        // end
        _indent = "";
        if (packageName != null && packageName.length() > 0)
        {
            StringTokenizer tokenizer =
                new StringTokenizer(packageName, "::");
            String token;

            while (tokenizer.hasMoreTokens() == true)
            {
                token = tokenizer.nextToken();
                ++packageDepth;

                _source.print(_indent);
                _source.print("module ");
                _source.println(token);
                _source.println();
                _indent += "    ";
            }
        }
        _source.print(_indent);
        _source.println("require 'statemap'");

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

        // Declare the inner state class.
        _source.println();
        _source.print(_indent);
        _source.print("class ");
        _source.print(context);
        _source.println("State < Statemap::State");
        _source.println();

        _source.print(_indent);
        _source.println("    def Entry(fsm) end");
        _source.println();
        _source.print(_indent);
        _source.println("    def Exit(fsm) end");
        _source.println();

        // Get the transition list.
        // Generate the default transition definitions.
        transitions = fsm.getTransitions();
        for (SmcTransition trans: transitions)
        {
            params = trans.getParameters();

            // Don't generate the Default transition here.
            if (trans.getName().equals("Default") == false)
            {
                _source.print(_indent);
                _source.print("    def ");
                _source.print(trans.getName());
                _source.print("(fsm");

                for (SmcParameter param: params)
                {
                    _source.print(", ");
                    _source.print(param.getName());
                }

                _source.println(")");

                // 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.print(_indent);
                _source.println("        Default(fsm)");

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

        // Generate the overall Default transition for all maps.
        _source.print(_indent);
        _source.println("    def Default(fsm)");

        if (Smc.isDebug() == true)
        {
            _source.print(_indent);
            _source.println(
                "        if fsm.getDebugFlag then");
            _source.print(_indent);
            _source.println(
                "            fsm.getDebugStream.write(\"TRANSITION   : Default\\n\")");
            _source.print(_indent);
            _source.println("        end");
        }

        _source.print(_indent);
        _source.println(
            "        msg = \"\\nState: \" + fsm.getState.getName +");
        _source.print(_indent);
        _source.println(
            "            \"\\nTransition: \" + fsm.getTransition + \"\\n\"");
        _source.print(_indent);
        _source.println(
            "        raise Statemap::TransitionUndefinedException, msg");
        _source.print(_indent);
        _source.println("    end");

        // End of context class.
        _source.println();
        _source.print(_indent);
        _source.println("end");

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

        // The context class contains all the state classes as
        // inner classes, so generate the context first rather
        // than last.
        _source.println();
        _source.print(_indent);
        _source.print("class ");
        _source.print(context);
        _source.println("_sm < Statemap::FSMContext");

        // Generate the context class' constructor.
        _source.println();
        _source.print(_indent);
        _source.println("    def initialize(owner)");
        _source.print(_indent);
        _source.println("        super()");
        _source.print(_indent);
        _source.println("        @_owner = owner");

        _source.print(_indent);
        _source.print("        setState(");
        _source.print(startState);
        _source.println(")");

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

        _source.print(_indent);
        _source.println("    end");
        _source.println();

        // Generate the transition methods.
        for (SmcTransition trans: transitions)
        {
            transName = trans.getName();
            params = trans.getParameters();

            if (transName.equals("Default") == false)
            {
                _source.print(_indent);
                _source.print("    def ");
                _source.print(transName);
                if (params.size() != 0)
                {
                    _source.println("(*arglist)");
                }
                else
                {
                    _source.println("()");
                }

                // Save away the transition name in case it is
                // need in an UndefinedTransitionException.
                _source.print(_indent);
                _source.print("        @_transition = '");
                _source.print(transName);
                _source.println("'");

                _source.print(_indent);
                _source.print("        getState.");
                _source.print(transName);
                _source.print("(self");

                if (params.size() != 0)
                {
                    _source.print(", *arglist");
                }
                _source.println(")");
                _source.print(_indent);
                _source.println("        @_transition = nil");

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

        // getState() method.
        _source.print(_indent);
        _source.println("    def getState()");
        _source.print(_indent);
        _source.println("        if @_state.nil? then");
        _source.print(_indent);
        _source.println(
            "            raise Statemap::StateUndefinedException");
        _source.print(_indent);
        _source.println("        end");
        _source.print(_indent);
        _source.println("        return @_state");
        _source.print(_indent);
        _source.println("    end");
        _source.println();

        // getOwner() method.
        _source.print(_indent);
        _source.println("    def getOwner()");
        _source.print(_indent);
        _source.println("        return @_owner");
        _source.print(_indent);
        _source.println("    end");
        _source.println();

        _source.print(_indent);
        _source.println("end");

        // If necessary, place an end for the module.
        if (packageName != null && packageName.length() > 0)
        {
            int i;
            int j;

            for (i = (packageDepth - 1); i >= 0; --i)
            {
                _source.println();
                // Output the proper indent.
                for (j = 0; j < i; ++j)
                {
                    _source.print("    ");
                }

                _source.println("end");
            }
        }

        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();
        String indent2;

        // 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.println();
        _source.print(_indent);
        _source.print("class ");
        _source.print(mapName);
        _source.print("_Default < ");
        _source.print(context);
        _source.println("State");

        // Declare the user-defined default transitions first.
        indent2 = _indent;
        _indent = _indent + "    ";
        for (SmcTransition transition: definedDefaultTransitions)
        {
            transition.accept(this);
        }
        _indent = indent2;

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

            // Generate the getTransitions() method.
            _source.println();
            _source.print(_indent);
            _source.println("    def getTransitions()");
            _source.print(_indent);
            _source.println("        return {");

            // Now place all transition names and states into the
            // map.
            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;
                }