Does Perl 6 have an infinite Int?

Question

I had a task where I wanted to find the closest string to a target (so, edit distance) without generating them all at the same time. I figured I'd use the high water mark technique (low, I guess) while initializing the closest edit distance to Inf so that any edit distance is closer:

use Text::Levenshtein;

my @strings = < Amelia Fred Barney Gilligan >;

for @strings {
    put "$_ is closest so far: { longest( 'Camelia', $_ ) }";
    }

sub longest ( Str:D $target, Str:D $string ) {
    state Int $closest-so-far = Inf;
    state Str:D $closest-string = '';

    if distance( $target, $string ) < $closest-so-far {
        $closest-so-far = $string.chars;
        $closest-string = $string;
        return True;
        }

    return False;
    }

However, Inf is a Num so I can't do that:

Type check failed in assignment to $closest-so-far; expected Int but got Num (Inf)

I could make the constraint a Num and coerce to that:

    state Num $closest-so-far = Inf;
    ...
        $closest-so-far = $string.chars.Num;

However, this seems quite unnatural. And, since Num and Int aren't related, I can't have a constraint like Int(Num). I only really care about this for the first value. It's easy to set that to something sufficiently high (such as the length of the longest string), but I wanted something more pure.

Is there something I'm missing? I would have thought that any numbery thing could have a special value that was greater (or less than) all the other values. Polymorphism and all that.

Does Perl 6 have an infinite Int?

1 Answers