On Sat, 25 Dec 2010 19:18:43 -0000, Robert Jacques <[email protected]>
wrote:
This @owned is very similar to previous 'scope' proposals (and oddly
dissimilar to previous owned proposals). To answer your question, under
previous proposals the scope keyword would allow you to declare that a
variable doesn't escape the current scope. So you could define external
functions that would take a 'scope int[]' and be guaranteed that it
wouldn't escape. (returning scoped values has to obey certain
restrictions)
The previous 'owned' proposals are a bit more general. Owned types allow
you parameterize a type on a variable, which sounds complex, but what it
means in terms of the runtime, is that all objects in the same ownership
group shared the same monitor. The big advantage is that inside a
synchronized method you don't have to synchronize other 'owned' objects
of the same type. It also makes this like unique a lot more viable,
since you can now define trees, etc.
Ok, I'll try to find previous proposals about 'scope' - now I cannot
understand
how you can prevent external function from, e.g., saving owned object or
array (i.e. references)
in global variable, if it's at all possible to pass owned variables into
external functions.
