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Parrot Branches
Code gets a little boring without flow control; for starters, Parrot knows about branching and labels. The branch op is equivalent to Perl's goto:
branch TERRY
JOHN: print "fjords\n"
branch END
MICHAEL: print " pining"
branch GRAHAM
TERRY: print "It's"
branch MICHAEL
GRAHAM: print " for the "
branch JOHN
END: end
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It can also perform simple tests to see whether a register contains a true value:
set I1, 12
set I2, 5
mod I3, I2, I2
if I3, REMAIND, DIVISOR
REMAIND: print "5 divides 12 with remainder "
print I3
branch DONE
DIVISOR: print "5 is an integer divisor of 12"
DONE: print "\n"
end
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Here's what that would look like in Perl, for comparison:
$i1 = 12;
$i2 = 5;
$i3 = $i1 % $i2;
if ($i3) {
print "5 divides 12 with remainder ";
print $i3;
} else {
print "5 is an integer divisor of 12";
}
print "\n";
exit;
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Parrot Operator
We have the full range of numeric comparators: eq, ne, lt, gt, le and ge. Note that you can't use these operators on arguments of disparate types; you may even need to add the suffix _i or _n to the op to tell it what type of argument you are using - although the assembler ought to divine this for you, by the time you read this.
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