Modern Perl for the Unfrozen Paleolithic Perl Programmer

If you last used Perl in the last century, you're probably frightened and confused about all the innovation that's happened in the Perl community when you weren't paying attention. If you come to this talk, you’ll learn the best practices around issues such as which version of Perl5 to use, Perl5 installation management, language features/libraries to use and avoid, modern tooling, and more!

Transcript

1. Modern Perl for the Unfrozen Paleolithic Perl Programmer John SJ Anderson ⭐ Infinity Interactive ⭐ @genehack YAPC::NA ⭐ 21 June 2016 ⭐ Orlando FL
2. Disclaimer I'mma talk pretty fast. Feel free to ask questions particularly if I'm moving too quickly
3. I'M JUST A CAVEMAN YOUR MODERN PERL FRIGHTENS AND CONFUSES ME I was inspired to give this talk by a few online friends who happen to be Perl programmers -- but they're not engaged with the community, they're just using Perl to get a job done, and there's a widening gulf between what I think is reasonable and what they're doing -- so I wanted to put together sort of an info dump
4. Welcome to 2016! So, hi, unfrozen caveman Perl programmer! Welcome to 2016!
5. Quite a few things have changed... Many things have changed since you fell into that glacier in 2001,
6. ...but many haven't
7. There's a Clinton running for President! Perl6 is still just about going to be released!
8. We're still using Perl5! Most of us are still happily coding in Perl5, however
9. 2001: Perl 5.6 When you slipped into that big hole in the ice, perl 5.6 was the latest and greatest
10. 2016: Perl 5.24 But we're all the way up to 5.24 now
11. Many language improvements
12. Unicode support! You probably don't remember Unicode -- it was around in 2001, but not terribly important or very well understood. It's way too complicated to get into here, just know that now we can get _really_ expressive in our Perl code
13. So it's much easier to tell if we're happy...
14. ... or when things aren't going quite as well.
15. This should be a familiar way of communication for you!
16. defined($this) ? $this : $that defined-or We got a great new feature in 5.10 called defined-or. You've probably written code much like this hundreds of times.
17. $this // $that defined-or Now, we can just write this! Which is pretty awesome. Defined-or was my favorite new perl feature of the 2000s
18. non-destructive s/// my $copy = $orig; $copy =~ s/swap/stuff/; new in 5.14
19. non-destructive s/// my $copy = $orig =~ s/swap/stuff/r; new in 5.14
20. postfix dereferencing @{ $arrayref } postfix deref in 5.20; non-experimental in 5.24
21. postfix dereferencing $arrayref->@* postfix deref in 5.20; non-experimental in 5.24
22. double diamond <<>> double diamond (5.22)
23. subroutine signatures Finally, we've also recently gotten support for subroutine signatures - 5.20
24. sub add ($one, $two) { return $one + $two; } so we don't even have to unpack @_ ourselves! Who has started using subroutine signatures?
25. new tools It's not just language level features, we also have a host of new tools to make it easier to work with Perl
26. "system" perl: These days, we make a distinction between the Perl that comes with your OS
27. "system" perl: just say no and encourage people not to use it for their development projects
28. /usr/bin/perl Yes, that means good old /usr/bin/perl...
29. /usr/bin/perl is no more. Instead, we use tools to install new Perls, outside the control of the OS
30. perlbrew The first tool that was developed for this purpose is called Perlbrew
31. perlbrew.pl which you can get at perlbrew.pl
32. plenv there's also a newer option, plenv
33. https://github.com/tokuhirom/plenv its website isn't quite as snazzy as perlbrew's
34. advantages • Solves "vendor Perl lockin" issues • Install multiple Perls in your home directory • ... or elsewhere • Trivially switch from Perl version to Perl version • Able to install modules without special permissions • Easy to stay up to date with Perl development either one of these tools will give you numerous advantages over using the system perl
35. plenv > perlbrew • Less magic messing around with PATH • Can "pin" Perl different ways: globally, per-shell, or per-directory personally, i'm using plenv these days -- the ability to easily specify a Perl version for a particular project is particularly useful to me
36. perlbrew > plenv • Kickass website
37. speaking of installing in your $HOME…
38. local::lib
39. local::lib • Install your own copies of modules • In your $HOME (so no special permissions needed) • Can also install per-project modules • Integrates well with other tools
40. speaking of installing stuff…
41. cpanminus a/k/a cpanm We've got a new CPAN client these days
42. % cpan Git::Wrapper CPAN: Storable loaded ok (v2.54) Reading '/Users/genehack/.cpan/Metadata' Database was generated on Sat, 10 Oct 2015 01:17:02 GMT Running install for module 'Git::Wrapper' CPAN: LWP::UserAgent loaded ok (v6.13) Fetching with LWP: http://cpan.schatt.com/authors/id/G/GE/GENEHACK/Git-Wrapper-0.045.tar.gz CPAN: YAML loaded ok (v1.15) CPAN: Digest::SHA loaded ok (v5.95) Fetching with LWP: http://cpan.schatt.com/authors/id/G/GE/GENEHACK/CHECKSUMS CPAN: Compress::Zlib loaded ok (v2.068) Checksum for /Users/genehack/.cpan/sources/authors/id/G/GE/GENEHACK/Git- Wrapper-0.045.tar.gz ok tmp-47326 for tmp-47326: No such file or directory at /opt/plenv/versions/5.23.2/lib/ perl5/5.23.2/CPAN/Distribution .pm line 468. CPAN: File::Temp loaded ok (v0.2304) CPAN: CPAN::Meta::Requirements loaded ok (v2.133) CPAN: Parse::CPAN::Meta loaded ok (v1.4417) CPAN: CPAN::Meta loaded ok (v2.150005) CPAN: Module::CoreList loaded ok (v5.20150820) Configuring G/GE/GENEHACK/Git-Wrapper-0.045.tar.gz with Makefile.PL Locating bin:git... found at /opt/git/bin/git. Checking if your kit is complete... Looks good Generating a Unix-style Makefile Writing Makefile for Git::Wrapper Writing MYMETA.yml and MYMETA.json this is the output from using the default 'cpan' client to install something.
43. GENEHACK/Git-Wrapper-0.045.tar.gz [17/1516] /opt/plenv/versions/5.23.2/bin/perl5.23.2 Makefile.PL -- OK Running make for G/GE/GENEHACK/Git-Wrapper-0.045.tar.gz cp lib/Git/Wrapper/File/RawModification.pm blib/lib/Git/Wrapper/File/RawModification.pm cp lib/Git/Wrapper.pm blib/lib/Git/Wrapper.pm cp lib/Git/Wrapper/Statuses.pm blib/lib/Git/Wrapper/Statuses.pm cp lib/Git/Wrapper/Exception.pm blib/lib/Git/Wrapper/Exception.pm cp lib/Git/Wrapper/Log.pm blib/lib/Git/Wrapper/Log.pm cp lib/Git/Wrapper/Status.pm blib/lib/Git/Wrapper/Status.pm Manifying 6 pod documents GENEHACK/Git-Wrapper-0.045.tar.gz /usr/bin/make -- OK Running make test PERL_DL_NONLAZY=1 "/opt/plenv/versions/5.23.2/bin/perl5.23.2" "-MExtUtils::Command::MM" "- MTest::Harness" "-e" "und ef *Test::Harness::Switches; test_harness(0, 'blib/lib', 'blib/arch')" t/*.t t/00-load.t ............... 1/6 # Testing Git::Wrapper 0.045 t/00-load.t ............... ok t/author-err.t ............ skipped: these tests are for testing by the author t/basic.t ................. # Testing git version: 2.5.2 t/basic.t ................. ok t/git_binary.t ............ ok t/parse_args.t ............ ok t/path_class.t ............ # Testing git version: 2.5.2 t/path_class.t ............ ok t/release-pod-coverage.t .. skipped: these tests are for release candidate testing t/release-pod-syntax.t .... skipped: these tests are for release candidate testing All tests successful. Files=8, Tests=67, 1 wallclock secs ( 0.04 usr 0.02 sys + 0.39 cusr 0.31 csys = 0.76 CPU) Result: PASS GENEHACK/Git-Wrapper-0.045.tar.gz and this is more of the output...
44. (still not done but I got tired of pasting.)
45. % cpanm Git::Wrapper --> Working on Git::Wrapper Fetching http://www.cpan.org/authors/id/G/GE/GENEHACK/Git-Wrapper-0.045.tar.gz ... OK Configuring Git-Wrapper-0.045 ... OK Building and testing Git-Wrapper-0.045 ... OK Successfully installed Git-Wrapper-0.045 this is the output from cpanm installing the same thing
46. speaking of stuff on CPAN…
47. https://metacpan.org/ we have a whole new website for interacting with CPAN
48. search.cpan.org search.cpan.org is still around...
49. https://metacpan.org/ but metacpan integrates and visualizes a bunch of information in a really useful way
50. https://metacpan.org/ things like a syntax-highlighted source view, linking to home pages and code repos, showing test results, and the amount of activity in a project
51. https://github.com/CPAN-API/metacpan-web it's also open source, so if you can think of a way to make it better, you can
52. Duck Duck Go we also have a new search engine here in 2016. it's cool, and it's partially written in Perl
53. Duck Duck Go !cpanm The most useful feature, though, is ability to use 'bang searches' to restrict your search to a particular site - this is how you search metacpan
54. speaking of modules... if you haven't been playing close attention (and since you were frozen, you haven't been!) there are a few new modules you may have missed
55. JSON::MaybeXS anybody doing web development these days needs to interact with JSON - using JSON::MaybeXS will make sure that you have a JSON library available, picking the best one from a number of alternatives
56. Moose Moo To get a handle on how we do OOP in Perl these days, you should look into Moose -- and then when you're ready to write some code, you'll probably be able to get away with dropping down to Moo
57. CGI.pm is gone I do have some bad news for you -- CGI.pm has been pulled out of core
58. (not really) don't worry, you can still find it on CPAN
59. Plack But the current standard for web development in Perl is Plack/PSGI. Offers a number of advantages over CGI, and is the basis for all modern Perl web frameworks
60. speaking of Perl websites… we have quite a few new websites these days, which make it easier to keep up with the current state of things
61. http://cpanratings.perl.org/ one of the problems with cpan is there's just _so_ _much_ _stuff_ there. it can be hard to decide which one of a dozen different modules to use. cpanratings helps with this problem
62. http://cpanratings.perl.org/ you can see individual reviews, which version they're reviewing, and so on.
63. https://metacpan.org/ MetaCPAN links to reviews as well as showing an average review score
64. http://cpants.cpanauthors.org/ we also have CPANTS - automated testing of some best practices around module development
65. http://cpants.cpanauthors.org/ here's what that looks like for a particular module. super useful if you're not sure you're doing things the "right" way
66. https://metacpan.org/ MetaCPAN links to CPANTS too
67. http://prepan.org/ We also have PrePAN, which is a place to get feedback on module ideas you haven't even written yet
68. speaking of staying up to date on Perl news… we also have some sites that make it easier to keep up to date with what's going on in the perl world
69. http://perlweekly.com/ there's perl weekly, which is a once a week email newsletter aggregating perl related news from all over the web
70. http://blogs.perl.org/users/sawyer_x/ and in a recent development, sawyer has revived the p5p weekly email summary -- excellent if you want to keep up with what's going on with perl5 development but don't have time to follow the email list yourself
71. thanks!
72. questions?