Re: Fallbacks in Euphoria
- Posted by dcuny Jan 12, 2015
- 1687 views
Definitely interesting. The delete_routine() is a bit like that, being only called when the reference count drops to 0.
I should have mentioned that Lua has a gc fallback, too. That might actually be very useful when trying to wrap objects from other libraries.
One difference is that you can deliberately keep a table empty of key values in Lua, so you can force indexing to happen. In Euphoria, it's not quite the same because indexing is done via a numeric value, not a key/value pair.
So you could start with an empty sequence in Euphoria, and something like:
s = foo[1]
would fail the first time, calling the fallback. But as soon as you stored a value in the sequence,
s = foo[1]
would trigger correctly, which is a bit of a conundrum. So... what to do?
One option would be to allow access to the sequence that holds the fallback list, calling it meta. You could do anything you'd want with that sequence - even store data in it.
Of course, you couldn't access it directly, so you'd need some way to get and set the meta sequence.
- David
