Re: Yielding across lua_load

["Christian N." <cn00@...>]

On 2015-10-08 19:48 +0200, Soni L. wrote:
> On 08/10/15 02:21 PM, Patrick Donnelly wrote:
> > On Thu, Oct 8, 2015 at 7:55 AM, Soni L. <fakedme@gmail.com> wrote:
> > > Is it possible to yield across lua_load?
> > >
> > > --
> > > Disclaimer: these emails may be made public at any given time, with or
> > > without reason. If you don't agree with this, DO NOT REPLY.
> > $ lua
> > Lua 5.3.1  Copyright (C) 1994-2015 Lua.org, PUC-Rio
> > > coroutine.wrap(function() assert(load(function() coroutine.yield("a =
> > > 1") end)) end)()
> > stdin:1: stdin:1: attempt to yield across a C-call boundary
> > stack traceback:
> >          [C]: in ?
> >          stdin:1: in main chunk
> >          [C]: in ?
> I said lua_load.
>
> load() uses lua_call internally (not lua_callk)

I don't think that would be possible, as yielding would jump outside 
lua_load using longjmp, losing any information lua_load has stored on 
the C stack (probably even leaking memory). However, using something 
like the C++ library Boost.Context or Boost.Coroutine, a workaround 
might maybe be possible as these libraries provide a way to sort of save 
the C stack.