Big state machines

Vance Shipley <>
Mon Apr 25 07:32:55 CEST 2005

On Sat, Apr 23, 2005 at 08:50:47AM +0200, Ulf Wiger wrote:
}  Being explicit certainly has its advantages. I think the
}  main benefit of plain_fsm might be that it can also serve
}  as a library for people who want to handle system messages
}  explicitly - much like your sysFsm. Was there anything
}  missing in the plain_fsm utility functions that made you
}  write your own library? Or was it perhaps because I hadn't
}  documented the option of skipping the parse transform and
}  writing more or less the way you did?
By the time I was finished it did occur to me that I could have
used plain_fsm without the parse_transform however it wasn't 
clear when I started.  There do remain some differences though
and they all come down to the initial objectives.

You wrote plain_fsm for folks coming from the Erlang book and
migrating to an OTP environment.  I wrote sys_fsm for the gen_fsm
writer to advance to a purer use of Erlang.  As such sys_fsm is
more gen_fsm like, good or bad.


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