Re: Proposed feature: die on compile with undefined functions

On Wed, Jan 28, 2026 at 11:59:47AM -0600, David Condon wrote:
> 
> *1. Here is a problem*
> Scripts that have undeclared subroutines will run, even though the
> subroutines are not declared/loaded/whatever:
> 
> There are no syntax changes.  The only change is that undefined subroutines
> would be treated the same way that undefined scalars are treated.

s/undefined scalares/undeclared scalars/

> I want perl to check for the undefined function max before running the
> script, similarly to the way that this 1-line script:

> *4. Here are potential problems*
> 
> I am unaware of any.  I just want something that will happen anyway to
> happen sooner to save time.  This change *shouldn't *be buggy.

The problem is see is that it's extremely hard to detect if a function
will be defined by the time Perl tries to call it:

    use v5.42;
    require List::Util;
    List::Util->import("max");
    say max( 1..10, -1..7);

All of those lines happens at run time, and max is available by the time
it's called. At the end of compilation, though, max is not defined.

-- 
 Philippe Bruhat (BooK)

 You can always buy another house but you cannot put a price on a home.
                                    (Moral from Groo The Wanderer #63 (Epic))