On Wed, Nov 19, 2003 at 09:12:01AM -0600, Jonathan Scott Duff wrote:
: On Tue, Nov 18, 2003 at 09:36:31PM -0800, Larry Wall wrote:
: > As for the original question that started this whole silly thread,
: > control structures that return values should probably be considered
: > some kind of generator, and have an explicit "yield"-like statement
: > that is orthogonal to "last" and such. Such a generator would be
: > explicitly marked, as with "do {...}" above, only different. The
: > inside of such a generator after the loop is the natural place
: > to say what happens if nothing in the loop "works".
:
: I don't understand ... Do you mean something like this?
:
: confer {
: for @a -> $x { ... } || beget @results;
: }
:
: where "confer" is the do-like marker and "beget" is the yield-like
: statement. But why not this?
:
: for @a -> $x { ... } or do { ... }
:
: I need an example.
Sorry, I wasn't being very clear. It wouldn't be logically attached to
the outside of the for, but to the inside of the "confer", or whatever:
@foo = gather {
for @a -> $x { pick $x if mumble($x) }
DEFAULT { @results }
}
In which case you could also write:
@foo = gather {
DEFAULT { @results }
for @a -> $x { pick $x if mumble($x) }
}
But it might be clearer to put it outside:
@foo = gather {
for @a -> $x { pick $x if mumble($x) }
} or @results;
On the other hand, putting the default up front is clearer if the
block is long. Could even be something like:
@foo = gather is default(@results) {
for @a -> $x { pick $x if mumble($x) }
}
Larry
