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Postings from October 2008
On Wednesday, 1. October 2008 21:54:12 larry@cvs.perl.org wrote: > If you apply an assignment operator to a protoobject, it is assumed that > you are implementing some kind of notional "reduction" to an accumulator > -variable. To that end, the base operator is dropped and a simple > -assignment is done instead. Hence you may correctly write: > +variable. To that end, the operation is defined in terms > +of the corresponding reduction operator, where the protoobject > +becomes the operator's identify value. So if you say: > + > + $x -= 1; > + > +it is more or less equivalent to: > + > + $x = [-]() unless defined $x; # 0 for [-]() > + $x = $x - 1; > + > +and $x ends up with -1 in it, as expected. Can't we have that as a general feature of all operators? That is: my ($x, $y); say $x * $y; # prints 1 say $x + $y; # prints 0 It is a cleaver idea to make the operator choose an appropriate value for a Nothing value. Why having that only for meta operators? Regards, TSa. -- "The unavoidable price of reliability is simplicity" -- C.A.R. Hoare "Simplicity does not precede complexity, but follows it." -- A.J. Perlis 1 + 2 + 3 + 4 + ... = -1/12 -- Srinivasa RamanujanThread Previous | Thread Next