This approach fails for your given example input of 3.14159:

use strict;
use warnings;

use Test::More tests => 1;

my $val = 3.14159;
my $oldval = $val;

my $newval = do {
    use B;
    if ( not B::SVf_POK & B::svref_2object( \$val )->FLAGS or
         -1 != index $val, 'e' ) {
        $val = sprintf '%.4f', $val;
        $val =~ s/\.?0+$//
    }
    "$val"
};

is "$oldval", "$newval";

[download]

I think you have to either "round to an arbitrarily sane length" as your code does or else just go with the flow.

🦛

In reply to Re^2: Choosing namespace/name for (my first) CPAN module which is a sub-class of a well-known distribution by hippo
in thread Choosing namespace/name for (my first) CPAN module which is a sub-class of a well-known distribution by Anonymous Monk

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