• You have some examples of Perl code and you say, "it takes less lines to do this in Perl than to do this in Java". But you only give an example of the Perl code! So how am I supposed to believe you that it really takes less lines? (For the record, I *do* happen to believe you, but that's neither here nor there; you're preaching to the converted, here. :)

  And besides, saying that the program takes less lines of code isn't necessarily a reason for choosing Perl over Java. *Why* is it good that a Perl program takes less lines of code? (Maintenance, maybe?) Give them reasons, not just assertions.

• Make sure that your programs work.

  This program doesn't do what you think it does:

      my @elements = {'A'..'Z', 0 .. 9 };
      my $i = 0;
      my @regkey;
      while($i++ < 15) { push(@regkey,$elements[rand($#elements + 1)]); 
  +}
      print @regkey, "\n";
  [download]

  The biggest mistake is the initialization of @elements. Those should be parens, not curly braces. You have created a list of hash references. Your program prints out:

   HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80
  +e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HAS
  +H(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a90)HASH(0x80e4a
  +90)HASH(0x80e4a90)
  [download]

  And you really don't need that many lines to write that code (since that's one of your major points :)--

      my @elements = ('A'..'Z', 0..9);
      my $regkey = join '', map { $elements[ rand @elements ] } 1..15;
  [download]

  And I'm *sure* that people can golf that down, but that's not really the point. The point is that my code shows some strengths of Perl, rather than looking like ported Java code (synthetic variables, for one thing).

• Make it clearer *why* they should choose Perl. "Less lines of code" isn't necessarily a reason in itself, and if all of the local universities teach Java instead of Perl, they have a *very*, *very* good reason for choosing Java. You need to give them a counter-argument.

  Anticipate the arguments they're going to give for languages other than Perl. "Java is an industry standard"; "Java is faster"; "Students are learning Java"; etc. Give counter-arguments for these.

• You say:

      > However, the re engine in Perl is far more sophisticated and
      > capable of better matches
  [download]

  "Better matches"? What does that mean? Does that mean, using the same regular expression (eg. "\w+"), I can match "better" strings in Perl than in Java? :)

  I think what you mean to say is: Perl has a more powerful regular expression engine. And then you need to find examples of *how* it is more powerful.

• One thing about Perl that is very, very good--that Java does not have--is CPAN. I really think you should mention CPAN. :)

  UPDATE: Oops, so you did mention CPAN. However, I think you should make it a stronger point. :)

A couple of thoughts:

• Drop the regex. It's practically unreadable and if any has heard of the FUD regarding Perl and linenoise, that will only encourage it.
• Go ahead and include the Amazon and eToys links. The odds are, many people who read your document will not follow your links.
• You mention that a company is thinking about adopting Perl as a development language. What sort of development? What are they trying to accomplish and how does Perl help them accomplish this? If they want device drivers or high-speed number crunching, Perl is not the best solution.

Incidentally, if you must include the regex, at least have pretty formatting so it looks nice:

$/ = ''; # paragrep mode
while (<>) {
    while ( m{
               \b      # start at a word boundary (begin letters)
                (      # capture to $1
                  \S+  #   one or more non-spaces
                )      # find chunk of non-whitespace
                \b     # until another word boundary (end letters)
                (      # capture to $2
                  \s+  #   separated by some whitespace
                  \1   #   whatever was in $1
                  \b   #   until another word boundary
                )+     # one or more sets of those
             }xig ) {
        print "dup word '$1' at paragraph $.\n";
    }
}
[download]

Just looking at that code, even when nicely formatted, makes me wince when I think about trying to convert anyone with it. Sure, we know what <>, $/, $., $1, and \1 mean, not to mention the /x, /i and /g modifiers on the regex, but those are going to scare the heck out of someone and make 'em long for Python or something.

If you show them some code, I think some 'baby Perl' would be a nice way to start.

Cheers,
Ovid

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For example you are building a simple system that takes user input from a form and puts it into a database.

With java - you need to build it, compile it, run it, and check the database.

With perl, you can code and test the routine that grabs the input. You can code and test the routine that builds the sql queries to put the data into the database. You can effectively code an entire system in parts, assemble and run.

I very often will work on one piece of a script at a time, and bash all the bits together when they all work. Can't do that with Java.

You certainly cannot build a one or two line piece of code to test regex's in Java.

Now in your situation, short - documented and runnable bits of code make training easier, and makes converting those *on the edge* easier.

Another neat touch would be make a java and perl version of the document, something that could put the document in a nice html format in their browser. Then show them the source code for each and (if possible) go through the steps to make a change or two. Edit-run vs edit-compile-run.

EEjack

1. First, even if one of the perlmonks links mentioned Amazon, there are so many links here that you can't be sure that'll be noticed, so you should make that explicit. It'll probably be taken more seriously than /. or pm, which raises a question...
2. ...is your audience going to be suits or coders? If the former, turns of phrase like "aiding and abetting" might not be a good idea if you trying to convince them of Perl's legitimacy.
3. I know you've got links to spare, but here's an excellent link I found today, surfing the Big Kahuna's home page. It's the only link on his page under "Advocacy":
   • The Importance of Perl by Tim O'Reilly and Ben Smith.
   It's got a lot about Perl vs. C/C++/Java, including for application development, and includes short versions of the success stories, including Amazon. It might make a good additional link; in any case, it should be worth reading for ideas.

-- Frag.

I agree with almost all the comments made to date. If I was writing this doc I would emphasise:

Perl has been around for many years (more than Java) and as a direct result all the major bugs have been ironed out.

Perl is very cross platform, and reliably so. Java still has some *issues* to use the term coined by the company of he who may not be named.

Open source and CPAN mean that library routines to perform most tasks are available that are not only widely used, but tested, updated, etc, etc

Perl can do OO just like Java. It can also do procedural. More importantly it can readily be developed in sections that can be easily and independently tested and debugged. Add the CPAN libray bit again where you note that there is a lot of *free* high quality, well tested code available - if you don't have to write and debug it you save time, money and hassles.

Give a really simple example of how Perl is shorter, this is C as I don't do Java although I am told it is similar.

In Perl:

print "Hello world\n";

In C:

#include <stdio.h>
   
int main()  
 {    
      printf("Hello World!\n");  
      return 0;
 }

So what if Perl code is shorter. I would emphasise easier to write, easier to test, easier to debug and easier to maintain - as a result *less cost* to implement any given solution. Bottom line $ terms is what really counts. This is why I would choose Perl over other languages for most (but not all) tasks.

Perl is interpreted Java half compiled into bytecode. Both are fast enough to do most jobs. Who cares which is faster if both are fast enough? Having to compile Java (or anything) for testing is a pain compared to Perl's ease of running and testing.

Target your audience. If it is suits emphasise development time, reliability, and dollars. If it is programmers emphasise laziness by utilising CPAN, ease of coding, plus whatever else you think might help.

With the links take one link from each domain. It kinda looks as though perlmonks.com is the only perl site in existence. Not that this is not a great site but you want to emphasise the wide use of perl, so give a wide variety of links to the same info.

Well that's my 10c worth

cheers

tachyon