Re: Are automatic coercions ever going away?

[Mike Nelson <mikestar1313@...>]

On 7/28/2014 12:32 PM, Coda Highland wrote:
> On Mon, Jul 28, 2014 at 12:15 PM, Luiz Henrique de Figueiredo
> <lhf@tecgraf.puc-rio.br> wrote:
> > > It sits rather deeply in the implementation.  [...]
> > > it is so troublesome that it has not been done yet
> > Not really. See http://lua-users.org/lists/lua-l/2014-03/msg00699.html
> Breaking tonumber() isn't exactly the same thing as removing implicit
> coercions -- it breaks explicit conversions too.
>
> /s/ Adam
This one is simple--make a copy of LuaV_tonumber with a new name (say 
LuaV_explicittonumber or whatever) but the old code, then set "tonumber" 
to a pointer to this new function. Explicit coercion via tonumber still 
works, but implicit string to number coercions are removed, without 
changing the various other code sites where LuaV_tonumber is called. I 
believe that number to string  coercions are not as easy to remove, but 
also not as troublesome to leave them in. If say, it is decided to do a 
very thorough code rewrite for Lua 6, definitely remove this 
auto-conversion then: not to suggest that such a rewrite should or 
shouldn't be done, that is purely the Lua authors' decision.