smcscalagenerator.java

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

                _source.print(transName);
                _source.print("\" -> ");
                _source.print(transDefinition);
                sep = ",";
            }
            _source.println();
            _source.println("    )");
            _source.println();
        }

        // The map class has been defined.
        _source.println("}");

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

        // Declare the map class.
        _source.println();
        _source.print("private object ");
        _source.print(mapName);
        _source.println(" {");

        // Declare each of the state class member data.
        for (SmcState state: states)
        {
            _source.print("    val ");
            _source.print(state.getInstanceName());
            _source.print(" = new ");
            _source.print(mapName);
            _source.print('_');
            _source.print(state.getClassName());
            _source.print("(\"");
            _source.print(mapName);
            _source.print('.');
            _source.print(state.getClassName());
            _source.print("\", ");
            _source.print(map.getNextStateId());
            _source.println(")");
        }

        // Create a default state as well.
        _source.print("    val Default = new ");
        _source.print(mapName);
        _source.print("_Default(\"");
        _source.print(mapName);
        _source.println(".Default\", -1)");

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

        return;
    } // end of visit(SmcMap)

    public void visit(SmcState state)
    {
        SmcMap map = state.getMap();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getClassName();
        List<SmcAction> actions;
        String indent2;

        _source.println();
        _source.print("private class ");
        _source.print(mapName);
        _source.print('_');
        _source.print(stateName);
        _source.print("(name: String, id: Int) extends ");
        _source.print(mapName);
        _source.println("_Default(name, id) {");

        // Add the Entry() and Exit() member functions if this
        // state defines them.
        actions = state.getEntryActions();
        if (actions != null && actions.size() > 0)
        {
            _source.println();
            _source.print("    override def Entry (context: ");
            _source.print(context);
            _source.println("Context): Unit = {");

            // Declare the "ctxt" local variable.
            _source.println("        val ctxt = context.getOwner()");
            _source.println();

            // Generate the actions associated with this code.
            indent2 = _indent;
            _indent = "        ";
            for (SmcAction action: actions)
            {
                action.accept(this);
            }

            _indent = indent2;

            // End the Entry() member function with a return.
            _source.println("    }");
        }

        actions = state.getExitActions();
        if (actions != null && actions.size() > 0)
        {
            _source.println();
            _source.print("    override def Exit (context: ");
            _source.print(context);
            _source.println("Context): Unit = {");

            // Declare the "ctxt" local variable.
            _source.print("        val ctxt: ");
            _source.print(context);
            _source.println(" = context.getOwner()");
            _source.println();

            // Generate the actions associated with this code.
            indent2 = _indent;
            _indent = "        ";
            for (SmcAction action: actions)
            {
                action.accept(this);
            }

            // End the Exit() member function with a return.
            _source.println("    }");
        }

        // Have each transition generate its code.
        _indent = "    ";
        for (SmcTransition transition: state.getTransitions())
        {
            transition.accept(this);
        }

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

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

            // Now output the transition collection's
            // initialization.
            _source.println();
            _source.print("    override 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 in this state, then its
                // value is 1.
                if (stateTransitions.contains(
                        transition) == true)
                {
                    transDefinition = 1;
                }
                // If the transition is defined in this map's
                // default state, then the value is 2.
                else if (defaultTransitions.contains(
                             transition) == true)
                {
                    transDefinition = 2;
                }
                // Otherwise the value is 0 - undefined.
                else
                {
                    transDefinition = 0;
                }

                _source.println(sep);
                _source.print("        \"");
                _source.print(transName);
                _source.print("\" -> ");
                _source.print(transDefinition);
                sep = ",";
            }
            _source.println();
            _source.println("    )");
            _source.println();
        }

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

        return;
    } // end of visit(SmcState)

    public void visit(SmcTransition transition)
    {
        SmcState state = transition.getState();
        SmcMap map = state.getMap();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getClassName();
        String transName = transition.getName();
        List<SmcParameter> parameters =
            transition.getParameters();
        List<SmcGuard> guards = transition.getGuards();
        boolean nullCondition = false;
        Iterator<SmcParameter> pit;
        Iterator<SmcGuard> git;
        SmcGuard guard;

        _source.println();
        _source.print(_indent);
        _source.print("override def ");
        _source.print(transName);
        _source.print("(context: ");
        _source.print(context);
        _source.print("Context");

        // Add user-defined parameters.
        for (SmcParameter parameter: parameters)
        {
            _source.print(", ");
            parameter.accept(this);
        }
        _source.println("): Unit = {");

        // All transitions have a "ctxt" local variable.
        // 8/14/2003:
        // Do this only if there are any transition actions or
        // guard conditions which reference it.
        if (transition.hasCtxtReference() == true)
        {
            _source.print(_indent);
            _source.print("    ");
            _source.print("val ctxt: ");
            _source.print(context);
            _source.println(" = context.getOwner()");
            _source.println();
        }

        // Output transition to debug stream.
        if (Smc.isDebug() == true)
        {
            String sep;

            _source.print(_indent);
            _source.println("    if (context.getDebugFlag())");
            _source.print(_indent);
            _source.print("        context.getDebugStream().println(");
            _source.print("\"TRANSITION   : ");
            _source.print(mapName);
            _source.print('.');
            _source.print(stateName);
            _source.print('.');
            _source.print(transName);

            _source.print('(');
            for (pit = parameters.iterator(), sep = "";
                 pit.hasNext() == true;
                 sep = ", ")
            {
                _source.print(sep);
                (pit.next()).accept(this);
            }
            _source.print(')');

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

        // Loop through the guards and print each one.
        for (git = guards.iterator(),
                 _guardIndex = 0,
                 _guardCount = guards.size();
             git.hasNext() == true;
             ++_guardIndex)
        {
            guard = git.next();

            // Count up the guards with no condition.
            if (guard.getCondition().length() == 0)
            {
                nullCondition = true;
            }

            guard.accept(this);
        }

        // If all guards have a condition, then create a final
        // "else" clause which passes control to the default
        // transition. Pass all arguments into the default
        // transition.
        if (_guardIndex > 0 && nullCondition == false)
        {
            if (_guardCount == 1)
            {
                _source.print(_indent);
                _source.println("    }");
            }

            _source.print(_indent);
            _source.println("    else {");

            // Call the super class' transition method using
            // the "super" keyword and not the class name.
            _source.print(_indent);
            _source.print("        super.");
            _source.print(transName);
            _source.print("(context");

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

            _source.println(")");
            _source.print(_indent);
            _source.println("    }");
            _source.println();
        }
        // Need to add a final newline after a multiguard block.
        else if (_guardCount > 1)
        {
            _source.println();
            _source.println();
        }

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

        return;
    } // end of visit(SmcTransition)

    public void visit(SmcGuard guard)
    {
        SmcTransition transition = guard.getTransition();
        SmcState state = transition.getState();
        SmcMap map = state.getMap();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getClassName();
        int transType = guard.getTransType();
        boolean defaultFlag =
            stateName.equalsIgnoreCase("Default");
        boolean loopbackFlag = false;
        String indent2;
        String indent3;
        String indent4;
        String endStateName = guard.getEndState();
        String fqEndStateName = "";
        String pushStateName = guard.getPushState();
        String condition = guard.getCondition();
        List<SmcAction> actions = guard.getActions();
        boolean hasActions = !(actions.isEmpty());

        // If this guard's end state is not of the form
        // "map::state", then prepend the map name to the
        // state name.
        // DON'T DO THIS IF THIS IS A POP TRANSITION!
        // The "state" is actually a transition name.
        if (transType != Smc.TRANS_POP &&
            endStateName.length () > 0 &&
            endStateName.equals("nil") == false)
        {
            endStateName = scopeStateName(endStateName, mapName);
        }

        // Qualify the state and push state names as well.
        stateName = scopeStateName(stateName, mapName);
        pushStateName = scopeStateName(pushStateName, mapName);

        loopbackFlag =
            isLoopback(transType, stateName, endStateName);

        // The guard code generation is a bit tricky. The first
        // question is how many guards are there? If there are
        // more than one, then we will need to generate the
        // proper "if-then-else" code.
        if (_guardCount > 1)