perl 'require' in begin block

module, perl, require, runtime

Solution

bignum's import needs to be called before compilation of the code it is intended to effect, or it doesn't work. Here, the BEGIN makes it called before your actual compute_factorial call, but not before the critical `my $factorial = 1;` is compiled.

A better approach for cases like this is just to directly use Math::Big*:

if (eval { require Math::BigInt }) {
    my $num = shift;
    my $factorial = Math::BigInt->new(1);
    foreach my $num (1..$num) {
        $factorial *= $num;                            
    }
    return $factorial;
} else {
    undef;
}

Problem

I have the following code: ``` #!/usr/bin/env perl use strict; use warnings; use feature 'say'; BEGIN { my $supported = undef; *compute_factorial = sub { if (eval { require bignum; bignum->import(); 1;}) { my $num = shift; my $factorial = 1; foreach my $num (1..$num) { $factorial *= $num; } return $factorial; } else { undef; } }; }; my $f = compute_factorial(25); say $f; ``` I'm just testing something, not really a production code... I do have `bignum` pragma on my machine (perfectly loadable using `use`), I was wondering why `require` doesn't work as it should be (I'm getting exponential numbers rather then "big numbers") in this case? Thanks,

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