Soft failures

In the previous example, the try block contained the instructions for both math calculations and printing the result. In real programs, these actions are often separated. Let us re-write the program so that it divides the numbers in a separate subroutine:

my $a = prompt 'Enter dividend > ';
my $b = prompt 'Enter divisor > ';
my $c = calculate($a, $b);
say 'Now ready to print';
say "The result of $a / $b is $c.";
say 'Done.';

sub calculate($a, $b) {
    return $a / $b;
}

Now the dangerous action happens inside the calculate function and the result is used outside it.

Run the program with values that should cause exception:

$ perl6 division.pl
Enter dividend > 10
Enter divisor > 0
Now ready to print
Attempt to divide 10 by zero using div
  in block <unit> at 06.pl line 7

Actually thrown at:
  in block <unit> at 06.pl line 7

Examine the output carefully. Before the exception message, the line Now ready to print appeared on the screen. At the time when it is...