Also:

  react { whenever }	# Code runs when a condition is met. 

I can only think this must be a generic https://en.wikipedia.org/wiki/COMEFROM. It is sure going to create some viciously subtle bugs.

Cf http://www.jnthn.net/papers/2015-spw-concurrency.pdf

From pages 56 and 57:

> Perl 6 has an asynchronous looping construct called whenever ... runs whenever a value arrives ... can live in a ... react block (works like entering an event loop)

  my $code = supply {
    whenever IO::Notification.watch-path($src-dir) {
      emit .path if .path ~~ /<.pm .p6> $/;
    }
  }

So now, whenever something in $src-dir changes and its path ends with '.pm' or '.p6' that path will be emitted -- which in this case means it'll be pushed to any construct pulling from $code. Such as:

  react {
    whenever $code -> $path {
      say "Code file $path changed!";
    }
  }

This is probably the most interesting link in this entire thread.

The "react" keyword is just a channel subscription, and inside it has a pattern matcher. Channels are first-class citizens, and you're encouraged to chain channels rather than falling into callback hell. It's like Go and Ruby had a child.

If anything piqued my interest in Perl 6, it was this.

INTERCAL finally weeps for joy at being able to claim Perl 6 as a spiritual descendant.

Nice to know I'm not the only one who thought that. Now they just need the PLEASE keyword.

That construct reminds me most of callbacks: you define some code, and register it to be called in certain circumstances.

One of my favorite new features is phasers[1] (loop flow control shortcuts), and as a subcomponent of that, how CATCH[2] is implemented as a phaser so it's within the block that had the error still has access to the variables in the same scope.

1: http://design.perl6.org/S04.html#Phasers

2: http://design.perl6.org/S04.html#Exception_handlers

If I'm not mistaken, that probaby should have read $++;

Correct. $ is an anonymous scalar (which autovivifies to 0 and increments in $++). There's also anonymous array @ and anon hash %. The hash form you can see in action here, in the one-liner mad-libs code: http://rosettacode.org/wiki/Mad_Libs#Perl_6

This. This thread right here is the magic of Perl.

I also attended the unveiling yesterday; If I remember correctly, I'm about 95% sure your assumption is correct.