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Postings from September 2013
On Fri, Sep 06, 2013 at 07:24:44PM -0700, James E Keenan via RT wrote:
> > On Wed Oct 25 08:41:02 2000, hv@crypt.compulink.co.uk wrote:
> > > (After a report in clp.moderated from Peter Scott <peter@psdt.com>.)
> > >
> > > perl -Dr -we '(($y) = "x") =~ s/a/b/'
> > >
> > > shows that a) perl is trying to perform the substitution on the string
> > > '1' which is not what the caller intended, and b) '1' is not marked
> > > readonly in this context, so no error is reported. I think both of
> > > these are bugs: I think the former should be fixed by giving an error
> > > if the LHS of a binding operator is supplied as a list, and that the
> > > latter should be fixed (if still relevant) by marking the count of
> > > list elements as readonly.
I don't think either of these are bugs.
In the first instance, its a list assignment evaluated in scalar context,
which is well-defined as returning the number of elements assigned.
The result may be slightly unexpected to the uninitiated, but its no
different than say
$count = (($y) = "x");
which sets count to 1.
In the second instance, (($y) = "x") in scalar context is an expression
that returns a well-defined numeric value. I see no rationale for it
to be read-only, any more than any other expression should return a
read-only value.
--
In economics, the exam questions are the same every year.
They just change the answers.
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