Re: `require()` semantics?

[Rob Hoelz <rob@...>]

If you want to compare notes with another implementation, I've done the
same thing with lua-procure:

https://github.com/hoelzro/lua-procure

-Rob

On Wed, 25 Jun 2014 00:04:25 +0200
Pierre-Yves Gérardy <pygy79@gmail.com> wrote:

> I already spotted a bug:
> 
> -            if loader == nil then
> +            if type(loader) ~= "function" then
> —Pierre-Yves
> 
> 
> On Tue, Jun 24, 2014 at 11:49 PM, Pierre-Yves Gérardy
> <pygy79@gmail.com> wrote:
> > I've adapted the simplifed `require()` found in PiL 2nd ed. to
> > hopefully match the C implementation (beside the stack trace that
> > starts one level deeper).
> >
> > It works around an "yield across C boundary" issue when using the
> > MoonScript loader with OpenResty. The first resumes a coroutine at
> > parse time, and the latter runs request handlers in coroutines.
> > Requiring a MoonScript file from a handler breaks because of this,
> > since `require()` is a C function.
> >
> > I plan to release it as a Rock and want to make sure it is correct.
> >
> > For Lua 5.1:
> >
> >     -- package and package.loaded are cached, while package.loaders
> > isn't. local package, p_loaded = package, package.loaded
> >
> >     function require (name)
> >         if not p_loaded[name] then
> >             local msg = {}
> >             local loader
> >             for _, searcher in ipairs(package.loaders) do
> >                 loader = searcher(name)
> >                 if type(loader) == "function" then break end
> >                 if type(loader) == "string" then
> >                     -- `loader` is actually an error message
> >                     msg[#msg + 1] = loader
> >                 end
> >             end
> >             if loader == nil then
> >                 error("module '" .. name .. "' not
> > found:"..table.concat(msg), 2)
> >             end
> >             p_loaded[name] = true
> >             local res = loader(name)
> >             if res ~= nil then
> >                 p_loaded[name] = res
> >             end
> >         end
> >         return p_loaded[name]
> >     end
> >
> > While I'm at it, is it correct for Lua 5.2?
> >
> > -            local loader
> > +            local loader, param
> > -              loader = searcher(name)
> > +              loader, param = searcher(name)
> > -          local res = loader(name)
> > +          local res = loader(name, param)
> >
> > Thanks in advance :-)
> >
> > —Pierre-Yves
>