I don't know about "shorter, more economical", but perhaps easier to maintain:
## a dispatch table in the form state => CODEref
my %operation = (
1 => \&do_this,
0 => \&do_that,
9 => \&do_another_thing,
);
## a table of transitions in the form pattern => state
my @transition = (
[ $Start => 1 ],
[ $Finish => 0 ],
[ $Break => 9 ],
);
my $State = 0; # or whatever your initial state is.
for my $item (@Input) {
# check transition conditions in order; if met, change state
for my $trans (@transition) {
next unless $item =~ /$trans->[0]/;
$State = $trans->[1];
last;
}
$operation->{$State}->(); # dereference and execute op for this S
+tate
}
That's a very simple state machine that uses a dispatch table. It's pretty easy to expand: add transitions to the @transition structure, write a sub for each operation and add it to the %operation dispatch table. You don't need to change any other code.
However, if you have a large number of states and/or transitions, using one of the state-machine modules that CountZero references above could be a better choice.
<–radiant.matrix–>
Ramblings and references
The Code that can be seen is not the true Code
I haven't found a problem yet that can't be solved by a well-placed trebuchet
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