Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Perl 6 Deep Dive

You're reading from   Perl 6 Deep Dive Data manipulation, concurrency, functional programming, and more

Arrow left icon
Product type Paperback
Published in Sep 2017
Publisher Packt
ISBN-13 9781787282049
Length 402 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Andrew Shitov Andrew Shitov
Author Profile Icon Andrew Shitov
Andrew Shitov
Arrow right icon
View More author details
Toc

Table of Contents (15) Chapters Close

1. What is Perl 6? FREE CHAPTER 2. Writing Code 3. Working with Variables and Built-in Data Types 4. Working with Operators 5. Control Flow 6. Subroutines 7. Modules 8. Object-Oriented Programming 9. Input and Output 10. Working with Exceptions 11. Regexes 12. Grammars 13. Concurrent Programming 14. Functional Programming 15. Reactive Programming

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...
lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at AU $24.99/month. Cancel anytime