Java on mobile phones, J2ME MIDP, unfortunately lacks the re?¬‚ection libraries that
contain invoke(). C# has Type.InvokeMember, which is rather wordy with a receiver
and ?¬?ve arguments, but basically similar to Java??™s invoke(). While C++ has poor
re?¬‚ection capabilities, it is possible to drop down to C function pointers or then use
member function pointers.
Overall, then, almost all languages support functions passing back the next
function to call, rather than calling it directly. As the code to make the call will only
appear once in the outermost loop of the program, even the frightening number of
arguments of C#??™s InvokeMember, or the equally unpleasant number of exceptions
thrown by Java??™s invoke(), should not put us off.
11.3.6 State Machine
State machines are among the earliest theories of computation, dating back to Turing
(1937), and even the most prevalent ???modern??? forms, Harel??™s statecharts (1987) and
SDL, are over 20 years old. They share many similarities with ?¬‚ow machines, and
much of the discussion above is thus relevant to generation of state machines. There
are however some important differences.
In normal ?¬‚owcharts, each object type can have its own kinds of exiting roles. For
instance, IF is exited via a True or False role, or a switch case is exited via any of the
various case values or the default case.
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