develooper Front page | perl.perl5.porters | Postings from January 2017

Re: Should we consider locked hashes a failed experiment?

Thread Previous | Thread Next
From:
demerphq
Date:
January 28, 2017 15:48
Subject:
Re: Should we consider locked hashes a failed experiment?
Message ID:
CANgJU+VzQkB6YbVdaCTYTVH_FrcMMCtG6YuNTxs_TPNiskmxOA@mail.gmail.com
On 28 January 2017 at 16:43, Leon Timmermans <fawaka@gmail.com> wrote:
> On Sat, Jan 28, 2017 at 3:31 PM, demerphq <demerphq@gmail.com> wrote:
>>
>> My experience with locked hashes is that as currently implemented they
>> are nearly useless. A simple read of a non-existent key becomes a
>> fatal exception, which makes them nearly unusable in conventional
>> code. At work we have tried to use them for a few purposes, and
>> generally it is has been a failure.  They impose a run time penalty on
>> all hash access even though they are barely used.
>
> As far as I know they're only used in the fields implementation, and were
> introduced when pseudohashes were abolished. I believe readonly hashes are
> generally far more useful, and that fields can be implemented quite easily
> on top of a pluggable hash API.

Agreed. And in the cases we have at $work we are using them for their
read-only'ness not their lockedness. (The difference is subtle. A read
only hash would allows one to read a nonexistent key without throwing
an exception. A locked hash throws an exception when you try to access
a key that was not known at the time of locking.)

Yves

-- 
perl -Mre=debug -e "/just|another|perl|hacker/"

Thread Previous | Thread Next


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About