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Re: ===, =:=, ~~, eq and == revisited (blame ajs!) -- Explained

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July 14, 2006 12:31
Re: ===, =:=, ~~, eq and == revisited (blame ajs!) -- Explained
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"Mark A. Biggar" schreef:
> Darren Duncan:

>> Now, I didn't see them yet anywhere in Synopsis 3, but I strongly
>> recommend having negated versions of all these various types of
>> equality tests.  Eg, !== for ===, nev for eqv, etc.  They would be
>> used very frequently, I believe (and I have even tried to do so),
>> and of course we get the nice parity.
> Yes and they should be strictly implicitly defined in term of the
> positive versions in such a way that you can't explicitly redefine
> them separately.  I.e., $x !== $y should always mean exactly the same
> thing as !($x === $y).  Maybe by a macro definition. To do otherwise
> would be very confusing as it would make such simple program
> transformations as:
>   say "foo" if $x !== $y;
> into
>   say "foo" unless $x === $y;

And how about symmetry:

  say "foo" unless $y === $x;

> very unreliable.

Affijn, Ruud

"Gewoon is een tijger."

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