dontlaugh/explanations.md

In Raku, Lists can be constructed several ways.

# A list of strings: "one", "two", "three"
my @x = <one two three>;
# Using << >> allows interpolating variables
my $num = "six";
my @y = << four five $six >>;

Classes get a new method automatically, where public attributes can be set in a key => "value" style.

class Person {
  has Str $.name;
}

my $p = Person.new(name => "Liz");

The object model allows overriding a TWEAK, which runs after the new method, and is convenient for setting up extra state while still taking advantage of automatic new.

TWEAK should almost always be a submethod (as opposed to a regular method) so that subclasses don't inherit it.

Examples of overidding TWEAK are in the class bodies below.

By the way: you don't need parens when calling subroutines.

sub foo($x, $y) {
  say "x: $x and y: $y";
}

foo(123, 456);
foo "blah", "blargh";

There's always more than one way to do it! Embrace and master the chaos.

You can pass blocks of code to subroutines, and they're indicated with the & sigil.

sub wrap-call(&b) {
  say "wrappin!";
  &b();
}

wrap-call({ say "nice" })
# prints:
# wrappin!
# nice

You can match lots of stuff with the ~~ smart match operator. A string against a regex literal for instance.

my $x = "Rolling Stones";
$x ~~ /Stone/;
if ?$/ {     # equivalent to $/.Bool
  say "I matched against the string";
}

The $/ is the "Match Variable", which is set to the result of the previous match. The ? prefix operator coerces it to a boolean.