develooper Front page | perl.perl6.language | Postings from April 2006

The "whatever" context

Thread Next
Yuval Kogman
April 9, 2006 04:44
The "whatever" context
Message ID:

I think that Perl 6 should have a "whatever" context, which is

	I want either array or scalar or whatever... You choose

so that functions like grep can return an array in "whatever"
context. This is best demonstrated using an example:

	my $x = grep { ... } @list; # returns count

	my $x = whatever grep { ... } @list; # the "natural" context for
	# grep is array, no matter what the context really is

The usefulness of such a construct is two fold:

a. creating large anonymous structures with nested references or
scalar values without having to think (== good for when you are
evaluating a fucntion ref and you don't know what it is, but you
want the "natural" value to be returned).

b. writing eval bots and interactive shells:

	(whatever eval $expr).perl;


  Yuval Kogman <>  0xEBD27418

Thread Next Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at | Group listing | About