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Postings from December 2001
"Brent Dax" <brentdax@cpan.org> writes:
> Piers Cawley:
> # In the following code fragment, what context is foo() in?
> #
> # @ary[0] = foo()
>
> The short answer is scalar context. The long answer is below. Note
> that the long answer is only the way I think of it. You may think
> differently.
>
> I like to think of it as 'one context'. 'Scalar' and 'list' no longer
> describe the whole situation. The way I see it, there are three types
> of context:
> -void context (which could just be 0 context)
> -N context
> -infinite context (which could just be Inf context)
>
> Ihe meaning of each of those should be obvious. In that case, 'scalar'
> context is really 'one' context. However, we can still call it scalar
> context if it makes you feel better. :^) (Yes, those are just my
> opinions. They do not necessarily reflect Larry's, Damian's or the guy
> in the padded cell next to mine's.)
Okay. Here's the examples I threw at Dan.
@ary[0] = foo() # scalar
@ary[1,2] = foo() # list context
@bar = 1;
@ary[@bar] = foo() # ? probably list or maybe scalar...
@bar = (1,2);
@ary[@bar] = foo() # list?
@bar is constant = 1;
@ary[@bar] = foo() # We know at compile time there's only one thing in
# @bar. Does that mean foo() is in a scalar context
# now?
sub a_scalar { 1 };
sub an_array { my @a = (1,2) }
sub context { wantarray ? (1,2) : 1 }
@ary[a_scalar()] = foo() # ???
@ary[an_array()] = foo() # ???
At around this point, Dan was heard to say 'Mommy, make the bad man go
away!'
@ary[context()] = foo() # ???
Oh yes, and what context is &context called in?
And, just for laughs:
$ref = [1,2];
@ary[$ref] = foo(); # probably a syntax error
--
Piers
"It is a truth universally acknowledged that a language in
possession of a rich syntax must be in need of a rewrite."
-- Jane Austen?
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