Re: [Patch] Finalization of function objects

[Thomas Harning <harningt@...>]

Nodir Temirhodzhaev wrote:
> > Luiz Henrique de Figueiredo sent:
> >
> > "Finalization of function objects" patch for Lua 5.1.2
> >
> > What is the rationale for this patch?
>
> For rationale see this old article:
> "Generic: Change the Way You Write Exception-Safe Code - Forever" ( 
> http://www.ddj.com/cpp/184403758).
>
> Patch is naive implementation of this idea and hint for Lua team.
Has there been any work on enhancing this?  I've found a few glitches on 
another machine that I haven't had the chance to get the code from...

Examples from memory...
Adding a finalizer for non-error then one for error... something 'wrong' 
happens....

print"-- Finalize on error"
do
   local function add5(x)
       finally(x, print, false)
       finally("Z", print, false)
       finally("Z", print, true)
       return x + 5
   end

   add5(5)
   assert(not pcall(add5), "Error expected")
   print"OK"
end
-----OUTPUT
-- Finalize on error
Z
Z    Z
nil    Z
OK


Another error I recall is when an error is thrown from a coroutine... no 
finalizers are executed in that case....