Re: Throwing an error on a yielded thread

["Sam Roberts" <vieuxtech@...>]

On Wed, Dec 3, 2008 at 3:17 AM,  <esmil@mailme.dk> wrote:
> Another option is to have some Lua code wrap all the C callbacks that
> might yield in an assert()-like function (or assert() itself) that

This is the essence of my suggestion. Of course you wouldn't litter
your code with raw calls to assert and coroutine.yield() as in my
example, you'd factor them into some nice functions so users or your
APIs would have the mechanics hidden from them.

> calls errors on some magic input, before any script is run. This
> just seems like a very inefficent and awkward solution to me.

Not sure what do you mean by inefficient? Wrapping calls that might
return nil, possibly because they were resumed, in an assert is pretty
easy!

Also, since you can't yield across C function calls, there's no
particular reason to not always do the yielding in the lua code that
wraps your C code. Its cleaner, in a way, since it allows you to test
your C bindings independently from the use of coroutines.

This technique is demonstrated:

  http://www.lua.org/pil/9.4.html

Note that the underlying C API (connection:receive()) doesn't yield,
the yield behaviour is implemented in lua on top of it, seperating the
concerns.

Cheers,
Sam