Junctions

any, all and | let one value be several values at once — and comparisons distribute over them.

A junction is a single value that is several values at once. Compare against it and the comparison distributes:

my $roll = 5;
if $roll == 1 | 3 | 5 {
    say 'odd roll';
}
say so 7 == any(2, 4, 7);

odd roll
True

1 | 3 | 5 and any(2, 4, 7) are the same idea — no need to write three comparisons and chain them with or.

all, any, one, none #

Each collapses to True under a different condition:

my @scores = 62, 75, 88;
say so all(@scores) >= 50;
say so any(@scores) > 80;
say so one(@scores) < 70;
say so none(@scores) == 100;

True
True
True
True

Read them aloud and they're already documentation: all scores at least 50; some score above 80; exactly one below 70; none equal to 100.

Junctions travel through calls #

Pass a junction to a function and the function runs for each member:

sub double($n) { $n * 2 }
say so double(any(2, 3)) == 6;

True

Try it #

Using all, check whether every word in the list is shorter than 8 characters.

my @words = <grammar junction whatever>;

my @words = <grammar junction whatever>;
say so all(@words).chars < 8;

False