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=head1 TITLE
|| should propagate result context to both sides.
=head1 VERSION
Maintainer: Peter Scott <[EMAIL PROTECTED]>
Date: 5 Aug 2000
Version: 1
Mailing List: [EMAIL PROTECTED]
Number: 45
=head1 ABSTRACT
Currently the expression
lvalue = expr_A || expr_B
evaluates C<expr_A> in scalar context, regardless of the type of C<lvalue>,
only propagating list or scalar context to C<expr_B>. This proposal is
that the context of C<lvalue> should be propagated to C<expr_A> as well.
=head1 DESCRIPTION
It would be nice to be able to say
@a = @b || @c
instead of having to resort to
@a = @b ? @b : @c
The reason that it is not currently possible is that C<@b> (or the list
expression in its place) has to be evaluated in scalar context to determine
whether to evaluate C<@c>, and that propagating context to C<@b> would
require reevaluating it, which might have undesirable side effects (instead
of C<@b>, it might be C<decrement_balance()>).
=head1 IMPLEMENTATION
It seems that it ought to be possible to evaluate something in a list
context and test whether there are any entries in the resulting list
without having to reevaluate the expression in a scalar context. The
work-around with the trinary operator also evaluates C<@b> twice.
There is obviously no need to modify the behavior of the C<&&> operator.
=head1 REFERENCES
L<perlop/"C-style Logical Or">
