smcperlgenerator.java

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

                _source.println(") {");
            }
            else
            {
                // This is not the first transition and it has
                // no condition.
                _source.println();
                _source.print(_indent);
                _source.println("    else {");
            }
        }
        // There is only one guard. Does this guard have
        // a condition?
        else if (condition.length() == 0)
        {
            // No. This is a plain, old. vanilla transition.
            indent2 = _indent + "    ";
        }
        else
        {
            // Yes there is a condition.
            indent2 = _indent + "        ";

            _source.print(_indent);
            _source.print("    if (");
            _source.print(condition);
            _source.println(") {");
        }

        // Now that the necessary conditions are in place, it's
        // time to dump out the transition's actions. First, do
        // the proper handling of the state change. If this
        // transition has no actions, then set the end state
        // immediately. Otherwise, unset the current state so
        // that if an action tries to issue a transition, it will
        // fail.
        if (actions.size() == 0 && endStateName.length() != 0)
        {
            fqEndStateName = endStateName;
        }
        else if (actions.size() > 0)
        {
            // Save away the current state if this is a loopback
            // transition. Storing current state allows the
            // current state to be cleared before any actions are
            // executed. Remember: actions are not allowed to
            // issue transitions and clearing the current state
            // prevents them from doing do.
            if (loopbackFlag == true)
            {
                fqEndStateName = "endState";

                _source.print(indent2);
                _source.print("my $");
                _source.print(fqEndStateName);
                _source.println(" = $fsm->getState();");
            }
            else
            {
                fqEndStateName = endStateName;
            }
        }

        // Decide if runtime loopback checking must be done.
        if (defaultFlag == true &&
            transType != Smc.TRANS_POP &&
            loopbackFlag == false)
        {
            _source.print(_indent);
            _source.print(
                "    my $loopbackFlag = $fsm->getState()->getName() eq $");
            _source.print(fqEndStateName);
            _source.println("->getName();");
        }

        // Dump out the exit actions - but only for the first
        // guard.
        // v. 1.0, beta 3: Not any more. The exit actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a pop transition.
        if (transType == Smc.TRANS_POP || loopbackFlag == false)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("unless ($loopbackFlag) {");
            }

            _source.print(indent4);
            _source.println("$fsm->getState()->Exit($fsm);");
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        // Dump out this transition's actions.
        if (actions.isEmpty() == true)
        {
            List<SmcAction> entryActions =
                state.getEntryActions();
            List<SmcAction> exitActions = state.getExitActions();

            if (condition.length() > 0)
            {
                _source.print(indent2);
                _source.println("# No actions.");
            }

            indent3 = indent2;
        }
        else
        {
            // Now that we are in the transition, clear the
            // current state.
            _source.print(indent2);
            _source.println("$fsm->clearState();");

            // v. 2.0.0: Place the actions inside a try/finally
            // block. This way the state will be set before an
            // exception leaves the transition method.
            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            if (Smc.isNoCatch() == false)
            {
                _source.print(indent2);
                _source.println("eval {");

                indent3 = indent2 + "    ";
            }
            else
            {
                indent3 = indent2;
            }

            indent4 = _indent;
            _indent = indent3;

            for (SmcAction action: actions)
            {
                action.accept(this);
            }

            _indent = indent4;

            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            if (Smc.isNoCatch() == false)
            {
                _source.print(indent2);
                _source.println("};");
                _source.print(indent2);
                _source.println("warn $@ if ($@);");
            }
        }

        // Print the setState() call, if necessary. Do NOT
        // generate the set state it:
        // 1. The transition has no actions AND is a loopback OR
        // 2. This is a push or pop transition.
        if (transType == Smc.TRANS_SET &&
            (actions.size() > 0 || loopbackFlag == false))
        {
            _source.print(indent2);
            _source.print("$fsm->setState($");
            _source.print(fqEndStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_PUSH)
        {
            // Set the next state so this it can be pushed
            // onto the state stack. But only do so if a clear
            // state was done.
            if (loopbackFlag == false || actions.size() > 0)
            {
                _source.print(indent2);
                _source.print("$fsm->setState($");
                _source.print(fqEndStateName);
                _source.println(");");
            }

            // Before doing the push, execute the end state's
            // entry actions (if any) if this is not a loopback.
            if (loopbackFlag == false)
            {
                if (defaultFlag == true)
                {
                    indent4 = indent2 + "    ";
                    _source.print(indent2);
                    _source.println("unless ($loopbackFlag) {");
                }
                else
                {
                    indent4 = indent2;
                }

                _source.print(indent4);
                _source.println(
                    "$fsm->getState()->Entry($fsm);");

                if (defaultFlag == true)
                {
                    _source.print(indent2);
                    _source.println("}");
                }
            }

            _source.print(indent2);
            _source.print("$fsm->pushState($");
            _source.print(pushStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_POP)
        {
            _source.print(indent2);
            _source.println("$fsm->popState();");
        }

        // Perform the new state's enty actions.
        // v. 1.0, beta 3: Not any more. The entry actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a push transition.
        if ((transType == Smc.TRANS_SET &&
             loopbackFlag == false) ||
             transType == Smc.TRANS_PUSH)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("unless ($loopbackFlag) {");
            }

            _source.print(indent4);
            _source.println("$fsm->getState()->Entry($fsm);");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        // If there is a transition associated with the pop, then
        // issue that transition here.
        if (transType == Smc.TRANS_POP &&
            endStateName.equals(NIL_STATE) == false &&
            endStateName.length() > 0)
        {
            String popArgs = guard.getPopArgs();

            _source.print(indent2);
            _source.print("$fsm->");
            _source.print(endStateName);
            _source.print("(");

            // Output any and all pop arguments.
            if (popArgs.length() > 0)
            {
                _source.print(popArgs);
                _source.println();
                _source.print(indent2);
                _source.println(");");
            }
            else
            {
                _source.println(");");
            }
        }

        // If this is a guarded transition, it will be necessary
        // to close off the "if" body. DON'T PRINT A NEW LINE!
        // Why? Because an "else" or "else if" may follow and we
        // won't know until we go back to the transition source
        // generator whether all clauses have been done.
        if (_guardCount > 1)
        {
            _source.print(_indent);
            _source.print("    }");
        }

        return;
    } // end of visit(SmcGuard)

    public void visit(SmcAction action)
    {
        String name = action.getName();
        Iterator<String> it;
        String sep;

        // Need to distinguish between FSMContext actions and
        // application class actions. If the action is
        // "emptyStateStack", then pass it to the context.
        // Otherwise, let the application class handle it.
        _source.print(_indent);
        if (name.equals("emptyStateStack") == true)
        {
            _source.print("$fsm->");
        }
        else
        {
            _source.print("$ctxt->");
        }
        _source.print(name);
        _source.print("(");

        for (it = action.getArguments().iterator(), sep = "";
             it.hasNext() == true;
             sep = ", ")
        {
            _source.print(sep);
            _source.print(it.next());
        }

        _source.println(");");

        return;
    } // end of visit(SmcAction)

//---------------------------------------------------------------
// Member data
//
} // end of class SmcPerlGenerator

//
// CHANGE LOG
// $Log: SmcPerlGenerator.java,v $
// Revision 1.9  2008/03/21 14:03:16  fperrad
// refactor : move from the main file Smc.java to each language generator the following data :
//  - the default file name suffix,
//  - the file name format for the generated SMC files
//
// Revision 1.8  2008/02/07 16:55:47  fperrad
// Perl : StateMachine::Statemap -> DFA::Statemap
//
// Revision 1.7  2008/02/04 10:26:51  fperrad
// Don't generate cuddled else
//
// Revision 1.6  2007/02/21 13:56:21  cwrapp
// Moved Java code to release 1.5.0
//
// Revision 1.5  2007/01/15 00:23:51  cwrapp
// Release 4.4.0 initial commit.
//
// Revision 1.4  2007/01/03 14:34:16  fperrad
// + Added -reflect option for Perl, Python and Ruby code generation
//
// Revision 1.3  2006/09/16 15:04:29  cwrapp
// Initial v. 4.3.3 check-in.
//
// Revision 1.2  2005/11/07 19:34:54  cwrapp
// Changes in release 4.3.0:
// New features:
//
// + Added -reflect option for Java, C#, VB.Net and Tcl code
//   generation. When used, allows applications to query a state
//   about its supported transitions. Returns a list of transition
//   names. This feature is useful to GUI developers who want to
//   enable/disable features based on the current state. See
//   Programmer's Manual section 11: On Reflection for more
//   information.
//
// + Updated LICENSE.txt with a missing final paragraph which allows
//   MPL 1.1 covered code to work with the GNU GPL.
//
// + Added a Maven plug-in and an ant task to a new tools directory.
//   Added Eiten Suez's SMC tutorial (in PDF) to a new docs
//   directory.
//
// Fixed the following bugs:
//
// + (GraphViz) DOT file generation did not properly escape
//   double quotes appearing in transition guards. This has been
//   corrected.
//
// + A note: the SMC FAQ incorrectly stated that C/C++ generated
//   code is thread safe. This is wrong. C/C++ generated is
//   certainly *not* thread safe. Multi-threaded C/C++ applications
//   are required to synchronize access to the FSM to allow for
//   correct performance.
//
// + (Java) The generated getState() method is now public.
//
// Revision 1.1  2005/06/16 18:11:01  fperrad
// Added C, Perl & Ruby generators.
//
//