smcpythongenerator.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 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: SmcPythonGenerator.java,v 1.11 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 Python code.
 * @see SmcElement
 * @see SmcCodeGenerator
 * @see SmcVisitor
 *
 * @author Francois Perrad
 */

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

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

    public void visit(SmcFSM fsm)
    {
        String context = fsm.getContext();
        String rawSource = fsm.getSource();
        String startState = fsm.getStartState();
        String pythonState;
        List<SmcMap> maps = fsm.getMaps();
        List<SmcTransition> transitions;
        List<SmcParameter> params;
        String transName;
        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();
        }

        _source.println("import statemap");
        _source.println();

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

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

        _source.println();
        _source.println("    def Entry(self, fsm):");
        _source.println("        pass");
        _source.println();
        _source.println("    def Exit(self, fsm):");
        _source.println("        pass");
        _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("    def ");
                _source.print(trans.getName());
                _source.print("(self, fsm");

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

                _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.println("        self.Default(fsm)");
                _source.println();
            }
        }

        // Generate the overall Default transition for all maps.
        _source.println("    def Default(self, fsm):");

        if (Smc.isDebug() == true)
        {
            _source.println(
                "        if fsm.getDebugFlag() == True:");
            _source.println(
                "            fsm.getDebugStream().write('TRANSITION   : Default\\n')");
        }

        _source.println(
            "        msg = \"\\n\\tState: %s\\n\\tTransition: %s\" % (");
        _source.println(
            "            fsm.getState().getName(), fsm.getTransition())");
        _source.println(
            "        raise statemap.TransitionUndefinedException, msg");

        // Generate the getTransitions() method.
        if (Smc.isReflection() == true)
        {
            _source.println();
            _source.println("    def getTransitions (self):");
            _source.println("        return self._transitions");
        }

        // 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("class ");
        _source.print(context);
        _source.println("_sm(statemap.FSMContext):");
        _source.println();

        // Generate the context class' constructor.
        _source.println("    def __init__(self, owner):");
        _source.println(
            "        statemap.FSMContext.__init__(self)");
        _source.println("        self._owner = owner");

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

        _source.print("        self.setState(");
        _source.print(pythonState);
        _source.println(")");

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

        _source.println();

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

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

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

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

                if (params.size() != 0)
                {
                    _source.print(", *arglist");
                }
                _source.println(")");
                _source.println(
                    "        self._transition = None");

                _source.println();
            }
        }

        // getState() method.
        _source.println("    def getState(self):");
        _source.println("        if self._state == None:");
        _source.println(
            "            raise statemap.StateUndefinedException");
        _source.println("        return self._state");
        _source.println();

        // getOwner() method.
        _source.println("    def getOwner(self):");
        _source.println("        return self._owner");
        _source.println();

        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();
        boolean needPass = true;

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

        // Declare the user-defined default transitions first.
        for (SmcTransition transition: definedDefaultTransitions)
        {
            needPass = false;
            transition.accept(this);
        }

        if (needPass == true && Smc.isReflection() == false)
        {
            _source.println("    pass");
        }

        // 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.println("    _transitions = dict(");

            // 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;
                }
                // Otherwise the value is 0 - undefined.
                else
                {
                    transDefinition = 0;
                }

                _source.print("        ");
                _source.print(transName);
                _source.print(" = ");
                _source.print(transDefinition);
                _source.println(",");
            }
            _source.println("    )");
        }

        // Have each state now generate its code. Each state
        // class is an inner class.
        for (SmcState state: states)
        {
            state.accept(this);
        }

        // Declare and initialize the map class.
        _source.println();
        _source.print("class ");
        _source.print(mapName);
        _source.println(':');
        _source.println();

        for (SmcState state: states)
        {
            _source.print("    ");
            _source.print(state.getInstanceName());
            _source.print(" = ");
            _source.print(mapName);
            _source.print('_');
            _source.print(state.getClassName());
            _source.print("('");
            _source.print(mapName);