What constitutes effective Perl training for non-Perl developers? [closed]

Answer 1

I'd start by telling them to always use the magical mantra:

use strict;
use warnings;

They don't need to know why (yet).

Next, I'd introduce them to perldoc and show them the basics of using it (the -f and -q flags, perldoc perl and perldoc perltoc, etc.) They need to know where to look when they have questions.

I'd talk about scalar vs. list context.

I'd introduce them to the basic data types (scalars, arrays, and hashes) and how the sigils follow the context, not the data type!

Introduce $_ and @_. It's critical to understand $_ because it's used in so many places, often implicitly. @_ is essential to writing subroutines. The other punctuation variables are used far less often and can wait.

Introduce them to regular expressions and get them used to the idea of regexes being first-class objects in Perl.

I'd briefly show them Perl's "diagonal" syntax. Idioms like next unless /foo/ are wonderful once you get use them but seem very alien when coming from other languages, particularly "orthogonal" ones.

You don't need to talk about references right away. Let that wait until they're ready to do things that require data structures. Functions like map and grep can wait, too.

Build a solid foundation on the fundamentals. Let them take baby steps for a while, then mix in more advanced features and idioms.

Answer 2

Frankly, I'd just give them the Camel. It's such a readable and entertaining book, they'll be up and running in no time. I'm still laughing about 'Perl holds truth to be self-evident' and it must be ten years since I first read it.

Answer 3

For C++/Java/C# coders two differences I stress very strongly up-front are that:

No 1: In Perl almost everything has a meaning, just not always what you want. Good examples include:

• Variable names without sigils don't stop execution - they are interpreted as barewords
• Try to store an array in a scalar and you get the length
• Try to store a hash in a scalar and you get 'a/b' (buckets in use vs total buckets?)

No 2: In Perl you can make it up as you go along. In other works you can say "in the hash 'w' the key 'x' indexes an anonymous array where box 'y' holds 'z'" and the interpreter will create and size all the variables for you as you go.

Answer 4

Check out the tables of contents for my books. Both Learning Perl and Intermediate Perl are designed to teach programmers the Perl language. We cover the 80% of Perl that most people use all of the time and developed that from years and years of teaching people Perl. Each book is designed as a tutorial, and there are exercises at the end of each chapter. I've also written the Learning Perl Student Workbook to provide additional exercises. Programming Perl is a good reference, too.

There are actually very few rules that you need to know to "get" Perl, and most people don't get these rules right just by looking at code. Some things to teach new Perlers who are coming from another language:

• strict and warnings
• Scalar versus list context
• dynamic versus lexical scope
• The sigil is not the variable type
• List creation and manipulation (map, grep, sort)
• How to use CPAN effectively
• Closures and subroutines as data
• Recursion in Perl sucks

Good luck :)

Answer 5

I think that the "killer app" of Perl is CPAN…

Typical quotes after browsing CPAN for the first time:

"You have a library for WHAT?"
"Extirpate HTML has to be the best function name ever!"
"You can summarize text in Perl?"

Once the programmers see how easy is to do hard things, they are sold.

Then you can show them perldoc and the Camel.

Answer 6

The most important thing you can show them is how to access the documentation, and how to find it (perldoc perltoc, perldoc -q $keyword, perldoc -f $function etc).

Perl comes with great documentation, including reference and tutorial-style material. Making that accessible to the newcomer is the most effective thing you can do for them.