Call/cc-like stuff in Perl 6...

cont.pl6

#!/usr/bin/perl6

use v6;

# call with current continuation
sub infix:<⇐> (&cont, &expr) {
	my @rest = expr &cont;
	return @rest[ 0 ] if @rest[ 1 ];
	return cont @rest[ 0 ];
}

sub infix:<⇒> ($x, $y) { $x == $y } # x evaluates to y?

sub prefix:<⇑> ($x) { $x, True }    # abort continuation
sub prefix:<⇓> ($x) { $x, False }   # pass expression

sub prefix:<λ> (&block) { &block }  # yep, a no-op / id function
sub infix:<×> ($x, $y) { $x * $y }  # alias to '*'

say (&(5 + *) ⇐ λ -> &k { ⇓ (4 × 3) }) ⇒ 17; # True
say (&(2 × *) ⇐ λ -> &k { ⇑ k (3) })   ⇒ 6;  # True

# end of script