- Why is there a `1;` on a single line in the middle of this file?
- What is `$_`?
- This parallel execution manager doesn't actually seem to define what code needs to run in parallel in any specific way, how does this work?
- What is this BEGIN block at the start of this Perl file? Why is that necessary?
- What's going on with qx, qw, qq?
- What does chomp do when it's just on its own line, with no arguments given to it?
$_ is inscrutable if you haven't studied perl, but the same thing would happen to anyone who sees a python decorator for the first time. what does "else: do after a while loop in python? Only people who know python know what it does (and I suspect most don't). The different quoting operators are also trivial to learn. In comparison, yield from python is also simple syntax but the semantics are much more involved.
BEGIN? Take 60 seconds to read what it means. And if you knew awk, you'd not have to do that, as it was directly lifted from awk.
And yet, as the industry grew and all sorts of people from all sorts of backgrounds converged in this space, the tolerance and appetite for funky/terse waned in favor of explicit/verbose/accessible. It's probably for the better in the end, but it did feel a little bit like the mom-and-pop store on the corner that had weird pickled things at the register and a meemaw in the back got replaced by a generic Circle K with a lesser soul.
This is an amazing point that I haven't seen anyone else make about languages in this way.
As someone who got into the industry right after Perl's heyday and never learned or used it but learned programming from some former Perl power users, Perl has a pre-corporate/anarchic/punk feel about it that is completely opposite to something like Golang that feels like it was developed by a corporation, for a corporation. Perl is wacky, but it feels alive (the language itself, if not the community). By contrast, Golang feels dead, soulless.
Perl and some of Perl's quirks will make more sense once you realise that it is deeply rooted in UNIX command line utilities, UNIX conventions and some UNIX shell defaults, except when it is not, i.e.
- What is `$_`?
$_ follows the spirit of shell variables (such as $*, $@, $! etc., heavily used in Korn, Bourne flavours but not the C flavours), but was repurposed or – more likely – picked from a pool of vacant characters with the help of a dice roll. Kind of like how ancient Egyptians built the pyramids with the help of sophisticated cranes and machinery and then vapourised their tools with high-particle beams to leave future generations guessing «how on Earth did they manage to do that». This is one of the main criticisms of Perl. - What is this BEGIN block at the start of this Perl file? Why is that necessary?
Perl started out as an improvement over «awk», and BEGIN is an awk construct where it is used frequently, e.g. awk 'BEGIN { IFS=":" } { … do something … }' - What does chomp do when it's just on its own line, with no arguments given to it?
It follows the standard convention of UNIX utilities that expect the input to come from the standard input stream (file descriptor 0 or <file-in in the shell) when no input file name has been specified. So, when no <FILE1> given to chomp, it chomps on the standard input.The Pragmatic Programmers had just started praising Ruby, so I opted for the that over Perl, and just went with it ever since. Hated PHP and didn't like Python's whitespace thing. I never Ruby on Rails'd either. That said my first interactive website was effectively a hello world button with cgi/perl.
But trying to learn to code from reading other peoples perl scripts was way harder than the (then) newer language alternatives.
Now I'm over 50 none of that is nearly as important. I remember being young and strongly opininated, this vs. that - its just part of the journey, and the culture. It also explains the current FizzBuzz in CSS minimisation post. We do because we can, not necessarily because we should.