From: Randal L. Schwartz <merlyn@stonehenge.com>
Date: Sat, 25 Mar 2006 15:07:38 GMT
Subject: Re: [PATCH 3/4] send-email: lazy-load Email::Valid and make it optional
Message-ID: <86zmje36md.fsf@blue.stonehenge.com>
In-Reply-To: <11432834111972-git-send-email-normalperson@yhbt.net>

>>>>> "Eric" == Eric Wong <normalperson@yhbt.net> writes:

Eric> +my $have_email_valid = eval { require Email::Valid or undef };

This is not necessary... if eval fails, it returns undef by definition.  Your
code presumes that the non-zero last-expression-evaluated of a require is also
returned from the require, which I believe is only accidentally true, although
the behavior may be recently documented and therefore promised.  (On perl 5.8,
it looks a bit fishy to me at a quick glance.)

My favorite idiom for a possibly failing eval-step is:

        my $can_I_do_this = eval { riskything; 1 };

If riskything fails, eval returns undef.  If it succeeds, it evaluates the 1,
and returns that.

-- 
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/>
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