[luatex] luatexbase.add_to_callback does not preserve the order

[Hironori KITAGAWA]

Hello David,

> I put a comment in github but I think that this fixes the issue (using
> ipairs rather than pairs in add_to_callback so the list is constituted
> in the right order)  Below I redefine add_to_callback in the test file
> but if you locally edit luatexbase.sty with that definition and could
> confirm it works on your original files, we will push an update to
> ctan, thanks again.

This works as expected, thank you!

Regards
Hironori KITAGAWA <h_kitagawa2001 at yahoo.co.jp>


On Wed, 3 Feb 2016 10:12:26 +0000
David Carlisle <d.p.carlisle at gmail.com> wrote:

> I put a comment in github but I think that this fixes the issue (using
> ipairs rather than pairs in add_to_callback so the list is constituted
> in the right order)  Below I redefine add_to_callback in the test file
> but if you locally edit luatexbase.sty with that definition and could
> confirm it works on your original files, we will push an update to
> ctan, thanks again.
> 
> 
> 
> \batchmode
> \input luatexbase.sty
> \directlua{
> function luatexbase.add_to_callback(name,fun,description,priority)
>   local priority= priority
>   local len=\string#luatexbase.callback_descriptions(name)
>   if (priority==nil) then
>    priority=len+1
>   end
>   if(luatexbase.callbacktypes[name] == 3 and
>      priority == 1 and
>      len==1) then
>     luatexbase.module_warning("luatexbase",
>                               "resetting exclusive callback: " .. name)
>     luatexbase.reset_callback(name)
>   end
>   local saved_callback={},ff,dd
>   for k,v in ipairs(luatexbase.callback_descriptions(name)) do
>     if k >= priority then
>       ff,dd= luatexbase.remove_from_callback(name, v)
>       saved_callback[1+k-priority]={ff,dd}
>     end
>   end
>   luatexbase.base_add_to_callback(name,fun,description)
>   for k,v in ipairs(saved_callback) do
>     luatexbase.base_add_to_callback(name,v[1],v[2])
>   end
>   return
> end
> }
> \scrollmode\catcode`\_=12
> 
> \directlua{
>   luatexbase.create_callback('test', 'data', function(n) return n end)
>   local fn = {}
>   for n=1,20 do
>     fn[n] = function()
>       texio.write(tostring(n) .. ', '); return 1
>     end
>     luatexbase.add_to_callback('test', fn[n], n, n)
>   end
>   luatexbase.call_callback('test', 0)
>   texio.write_nl('')
>   for i=1,300 do
>     local n = math.random(20)
>     luatexbase.remove_from_callback('test', n) % remove fn[n]
>     luatexbase.add_to_callback('test', fn[n], n, n)
>   end
>   texio.write_nl('')
>   luatexbase.call_callback('test', 0)
> }
> 
> \batchmode\bye