Hola, Some of us on #perl6 bitched once more about how lazy will make our IO brain hurt a lot.
The concensus is that a lazy context has not been discussed yet.
Here is a proposal for lazyness defined with coroutines.
we have a lazy modifier:
my $a = lazy { get_value(5, 10) };
my @array = lazy gather { ... take ... };
What it returns is a proxy object that vivifies to a true value, or
in the case of list context lazy, a proxy object array that
implements a generator.
The rvalue of the lazy context modifier is turned into a coro
closure, and is invoked only when the value is accessed.
Moreover, in lazy context, if the coro yields instead of finishing,
then it is not finalized into a real value. Here's how the range
operator would be implemented:
sub &infix:<..> ($from, $to where { $to < $from }){ reverse $to ..
$from }
sub &infix:<..> ($from, $to) { lazy gather {
while ($from <= $to) {
take($from++);
}
}}
In this case, take in lazy context gather would yield.
The only "builtin" feature that needs to be added is that coroutines
can masquerade as their return value, and not a code reference, but
AFAIK proxy objects will give us that anyway, right?
--
() Yuval Kogman <[EMAIL PROTECTED]> 0xEBD27418 perl hacker &
/\ kung foo master: /me wields bonsai kittens: neeyah!!!!!!!!!!!!!!!!
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