Course of Raku / Advanced / Debugging with dd

Function signatures

A bare dd called inside a function prints its signature: the name and the list of arguments it it has them. Examine the following example with two different functions.

sub f1 {
    dd
}

f1();

sub f2($x) {
    dd
}

f2(42);

The program prints:

sub f1()
sub f2($x)

If you have multi-function, this method helps to debug and see which multi-variant was called.

multi sub g {
    dd
}

multi sub g($x) {
    dd
}

g();
g(42);

The output is:

sub g()
sub g($x)