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

Answer 1

I own and manage Perl Training Australia. I've been teaching Perl for about eight years, and computer science for over a decade. I have strong opinions on not only Perl, but also on teaching, and presenting in general. I've written hundreds of pages of text about Perl -- which I won't be repeating here -- so what I'm going to give you isn't advice on teaching Perl; it's meta-advice instead.

Firstly, if your time and budget allows, consider sending your staff member on a professional Perl training course. Dedicated courses have the advantage that they don't come with work interruptions, they don't come with workplace politics, and they do come with someone who's very familiar with the difficulties people have when learning Perl. Please make sure you have a trainer who knows their stuff and is an active member of the Perl community; it means they should be able to answer any question thrown at them, or direct the questioner to an appropriate reference where they can learn more. Yes, I run a Perl training business, so I'm heavily opinionated here.

If for whatever reason you can't go with a dedicated course, then get a book that's specifically designed to teach people how to program in Perl, and walk through that. It's easy to miss things, or to try and introduce things in the wrong order, or (heaven forbid) teach bad habits, and all of those can make your life difficult. Often the people writing books designed to teach Perl are the same people who have successful Perl training businesses. If you want to buy a book, I'd recommend the latest version of Learning Perl. If you want to download a book, I'd recommend grabbing the Programming Perl course notes from the Perl Training Australia website.

Both of these books come with exercises, and this brings me to my last piece of meta-advice. Make sure anyone who is learning Perl does the exercises. It's very easy when learning any new skill to think you know what's going on, but discover that when putting things into practice it's harder than it looks. This is particularly the case with Perl, where programming concepts like "context" can apply, which are rare in other languages. Usually the exercises are specifically designed to teach a certain skill, or to highlight a certain pitfall; figuring these things out during learning is much easier than figuring them out on the eve of a project deadline.

Answer 2

Based on my experience in the workplace I'd recommend beginning with Perl's documentation (already covered here) and spend some time showing the student how to test code on the command line. It's really surprising how quickly someone can pick up a language when they can try something on the fly and make corrections until they get it right.

Answer 3

This is a single detail, not a full answer to your question, but for me, the mark of someone who's truly become oriented to Perl is someone who replaces this idiom:

for (my $i = 0; $i < @a; $i++)
{
  &do_something_with($array[$i]);
}

with this idiom:

foreach my $a (@array)
{
  &do_something_with($a);
}

Teach them lists as lists, not just as arrays. Teach the awesome data structures. Teach lists, hashes, lists of hashes, hashes of lists, hashes of hashes. That's where the biggest step up in power comes in over most conventional strongly-typed languages. (Ironically in the Java shop I joined this year, we sling around tons of arbitarily deep nested HashMap structures. Too many, in fact; I'm the one arguing for doing a bit less of it! But in Perl, this sort of thing is vital.)

Answer 4

Programming Perl (coauthored by #22483 - good work Randal, i've had mine for near on 10 years) was a great intro to Perl. Starting with regex, slicing and dicing arrays, associative arrays etc. Plus the whys and hows of reporting in Perl and a function reference.

I'm not sure how much it's changed in it's third edition but i would base a course on it and use it as the text book. It's reasonably terse and to the point. Plus then your course matches your documentation.

Answer 5

I'm a java programmer who recently had to pick up Perl. The part I found hardest to get used to were all the special built in variables like $_ $~ $' and so on. Until you get used to them it's hard to keep track of which one does what.

And, of course, the use of regular expressions.

For example, I have to maintain code and when I saw the line below for the first time it was a little confusing. As a java programmer it looks like gibberish.

next unless "$_" !~ /^#/;

Answer 6

I'd go for the variety of quoting operators (from perlop):

       Customary  Generic        Meaning        Interpolates
           ''       q{}          Literal             no
           ""      qq{}          Literal             yes
           ``      qx{}          Command             yes*
                   qw{}         Word list            no
           //       m{}       Pattern match          yes*
                   qr{}          Pattern             yes*
                    s{}{}      Substitution          yes*
                   tr{}{}    Transliteration         no (but see below)
           <<EOF                 here-doc            yes*

           * unless the delimiter is ''.

The list can be overwhelming (especially when you add in alternate delimiters), but extremely useful. It also helps when reading code since few (if any!) languages have the variety of quotes that Perl has.