Re: [PATCH 3/4] send-email: lazy-load Email::Valid and make it optional

From: Randal L. Schwartz <merlyn@stonehenge.com>
Date: Mar 25, 2006, 15:07 UTC
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.

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