On Thu, 2005-02-10 at 11:59, Luke Palmer wrote:
> There's been some discussion about bringing a syntax back for that
> recently, but I haven't really been paying attention. Anyway, this is
> pretty clear:
>
> loop {
> $foo = readline;
> do { stuff :with($foo) };
> last unless $foo;
> }
Well, yes it's clear, but then you run into the problem where your code
looks like:
while stuff() {
more_stuff();
}
loop {
other_more_stuff();
last unless other_stuff();
}
and then you want to add something like:
next if things();
to both... you have to do it in two ways. The Perl 6ish way of dealing
with this is:
while stuff() {
next if things();
more_stuff();
}
loop {
next if other_things();
other_more_stuff();
NEXT { last unless other_stuff(); }
}
I think Larry's contention has been that loop is all you really need,
and everything else is a macro. If you really want dowhile, then it's
something like (making up macro example on the fly, and probably wrong
here...):
macro infix:dowhile (Code $block, Bool $cond) {
loop { $block.(); NEXT { last unless $cond.() } }
}
{
next if other_things();
other_more_stuff();
} dowhile other_stuff();
Of course, that assumes that an expanded macro will, by default, handle
the case when you pass it code that invokes a loop control, expecting to
control the loop inside the macro first.
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