smcobjcgenerator.java

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

                // If -g was specified, then set the transition
                // name so it can be printed out.
                if (Smc.isDebug() == true)
                {
                    _source.print(_indent);
                    _source.print("    [self setTransition:@\"");
                    _source.print(trans.getName());
                    _source.println("\"];");
                }

                _source.print(_indent);
                _source.print("    [[self state] ");
                _source.print(trans.getName());
                _source.print(":self");
                for (pit = params.iterator();
                     pit.hasNext() == true;
                    )
                {
                    _source.print(" :");
                    _source.print((pit.next()).getName());
                }
                _source.println("];");

                if (Smc.isDebug() == true)
                {
                    _source.print(_indent);
                    _source.println(
                        "    [self setTransition:nil];");
                }

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

        // End the class implementation
        _source.print(_indent);
        _source.println("@end");

        return;
    } // end of visit(SmcFSM)

    public void visit(SmcMap map)
    {
        // Print out the default state class
        _source.println();
        _source.print(_indent);
        _source.print("@implementation ");
        _source.print(map.getName());
        _source.println("_Default");

        // Declare the user-defined default transitions first.
        if (map.hasDefaultState() == true)
        {
            SmcState defaultState = map.getDefaultState();

            for (SmcTransition transition:
                     defaultState.getTransitions())
            {
                transition.accept(this);
            }
        }

        _source.println("@end");

        // Have each state now generate its code.
        for (SmcState state: map.getStates())
        {
            state.accept(this);
        }

        return;
    } // end of visit(SmcMap)

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

        _source.print(_indent);
        _source.print("@implementation ");
        _source.print(mapName);
        _source.print("_");
        _source.println(className);

        // Add the Entry() and Exit() methods if this state
        // defines them.
        actions = state.getEntryActions();
        if (actions != null && actions.size() > 0)
        {
            _source.print(_indent);
            _source.print("- (void)Entry:(");
            _source.print(context);
            _source.println("Context*)context;");
            _source.println();
            _source.println("{");

            // Declare the "ctxt" local variable.
            _source.print(_indent);
            _source.print("    ");
            _source.print(context);
            _source.println(" *ctxt = [context owner];");
            _source.println();

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

            // End the Entry() method with a return.
            _source.print(_indent);
            _source.println("}");
        }

        actions = state.getExitActions();
        if (actions != null && actions.size() > 0)
        {
            _source.print(_indent);
            _source.print("- (void)Exit:(");
            _source.print(context);
            _source.println("Context*)context;");
            _source.println();
            _source.println("{");

            // Declare the "ctxt" local variable.
            _source.print(_indent);
            _source.print("    ");
            _source.print(context);
            _source.println(" *ctxt = [context owner];");
            _source.println();

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

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

        // Have the transitions generate their code.
        for (SmcTransition transition: state.getTransitions())
        {
            transition.accept(this);
        }

        _source.print(_indent);
        _source.println("@end");
        _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();
        boolean defaultFlag = false;
        boolean nullCondition = false;
        List<SmcGuard> guards = transition.getGuards();
        Iterator<SmcGuard> git;
        SmcGuard guard;
        String fqStateName;

        // Set a flag to denote if this is a Default state
        // transition.
        if (stateName.equals("Default") == true)
        {
            defaultFlag = true;
        }

        // Qualify the state name as well.
        if (stateName.indexOf("::") < 0)
        {
            fqStateName = "[" + mapName + " " + stateName + "]";
        }
        else
        {
            fqStateName = stateName;
        }

        _source.println();
        _source.print(_indent);
        _source.print("- (void)");
        _source.print(transName);
        _source.print(":(");
        _source.print(context);
        _source.print("Context*)context");

        // Add user-defined parameters.
        for (SmcParameter param: transition.getParameters())
        {
            _source.print(" :");
            param.accept(this);
        }

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

        // 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(context);
            _source.println(" *ctxt = [context owner];");
        }

        if (defaultFlag == true)
        {
            _source.print(_indent);
            _source.println("    BOOL loopbackFlag = NO;");
        }

        // Print the transition to the verbose log.
        if (Smc.isDebug() == true)
        {
            Iterator<SmcParameter> pit;
            String sep;

            _source.print(_indent);
            _source.println("    if ( [context debugFlag] )");
            _source.print(_indent);
            _source.println("    {");

            _source.print(_indent);
            _source.print("        TRACE(@\"TRANSITION   : ");
            _source.print(mapName);
            _source.print(" ");
            _source.print(transName);
            _source.print("(");

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

            _source.println(")\\n\\r\");");

            _source.print(_indent);
            _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 number of 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.
        if (_guardIndex > 0 && nullCondition == false)
        {
            // If there is only one transition definition, then
            // close off the guard.
            if (_guardCount == 1)
            {
                _source.print(_indent);
                _source.println("    }");
            }

            _source.print(_indent);
            _source.println("    else");
            _source.print(_indent);
            _source.println("    {");
            _source.print(_indent);
            _source.print("         ");
            _source.print(mapName);
            _source.print("_Default::");
            _source.print(transName);
            _source.print("(context");

            // Output user-defined parameters.
            for (SmcParameter param: transition.getParameters())
            {
                _source.print(", ");
                _source.print(param.getName());
            }
            _source.println(");");
            _source.print(_indent);
            _source.println("    }");
        }
        else if (_guardCount > 1)
        {
            _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();

        // 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.indexOf("::") < 0)
        {
            endStateName = mapName + "::" + endStateName;
        }

        // Convert the SMC scope syntex to the Objective-C
        // syntax.
        if (endStateName.indexOf("::") >= 0)
        {
            endStateName = convertScope(endStateName);
        }

        // Qualify the state name as well.
        if (stateName.indexOf("::") >= 0)
        {
            stateName = convertScope(stateName);
        }

        loopbackFlag =
            isLoopback(transType, stateName, endStateName);

        // v. 2.0.2: If the push state is not fully-qualified,
        // then prepend the current map's name and make if
        // fully-qualified.
        if (pushStateName != null &&
            pushStateName.length() > 0 &&
            pushStateName.indexOf("::") < 0)
        {
            pushStateName =
                "[" + mapName + " " + pushStateName + "]";
        }

        if (pushStateName.indexOf("::") >= 0)
        {
            pushStateName = convertScope(pushStateName);
        }

        // 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)
        {
            indent2 = _indent + "        ";

            // More than one guard. Is this the first guard?
            if (_guardIndex == 0 && condition.length() > 0)
            {
                // Yes, this is the first. This means an
                // "if" should be used for this condition.
                _source.print(_indent);
                _source.print("    if (");
                _source.print(condition);
                _source.println(")");