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Postings from February 2022
On Fri, 25 Feb 2022 01:24:00 -0600
David Nicol <davidnicol@gmail.com> wrote:
> IMO trim should operate in place in void context and return the
> substring in nonvoid context. Optimizing
Functions that do materially different things depending on context have
been a constant annoyance to newbies and experts alike, ever since the
language was first created. They are commonly agreed to be one of the
worst mis-features of the entire language.
What does this do?
sub shortname {
my $self = shift;
return trim( $self->{fullname} );
}
Does it mutate the object instance, or not? Perhaps it depends on the
caller.
Maybe far away in a script somewhere many files away:
printf "My shortname is %s\n", $user->shortname;
$user->shortname;
printf "Fullname is now %s\n", $user->{fullname};
Oops. We just broke the object.
This sort of "spooky action-at-a-distance" makes it hard to build
robust code and reason about its behaviour in small modular pieces.
--
Paul "LeoNerd" Evans
leonerd@leonerd.org.uk | https://metacpan.org/author/PEVANS
http://www.leonerd.org.uk/ | https://www.tindie.com/stores/leonerd/
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