# cmp. Generic, "smart" three-way comparator.

multi sub infix:<cmp>(Any,       Any)
multi sub infix:<cmp>(Real:D,    Real:D)
multi sub infix:<cmp>(Str:D,     Str:D)
multi sub infix:<cmp>(Version:D, Version:D)

# Compares strings with string semantics, numbers with number semantics, Pair objects first by key and then by value etc.
# if $a eqv $b, then $a cmp $b always returns Order::Same. Otherwise Order::Less or Order::More.

##</code><code>##

dd 'a ä b'.comb.sort;
(" ", " ", "a", "b", "ä").Seq;

##</code><code>##

subset CzechString of String;
multi sub infix:<cmp>(CzechString $a, CzechString $b) {
  # sort logic here
}

##</code><code>##

sub czech-sort(String $a, String $b) {
  # sort logic here
}

@czech-words.sort( &czech-sort );

##</code><code>##

dd ([1,'z'], [2,'a'], ['1', 'a']).sort( *.[0,1] );
(["1", "a"], [1, "z"], [2, "a"]).Seq

dd ([1,'z'], [2,'a'], ['1', 'a']).sort( { $^a[0] <=> $^b[0] || $^a[1] cmp $^b[1] });