Re: Change request for 5.2: luai_lnumdiv and luai_lnummod

[David Jones <drj@...>]

On 27 Jul 2006, at 14:49, John D. Ramsdell wrote:

> The file src/luaconf.h greatly eases the task of adjusting the type of
> numerical data used by Lua, however, if LUA_NUMBER is defined to be an
> integral type, the interpreter must throw an exception on divide by
> zero.

[to avoid invoking C's undefined behaviour]

>   The constant propagation code need not worry about divide by
> zero because it checks before it applies a reduction.  Therefore, the
> context in which luai_numdiv(a,b) is expanded in the constant
> propagation code does not have a lua_State available, while the
> interpreter does, and access to that state is needed to signal an
> exception.  Please provide a macro for use in each environment.


Seconded.

There are floating point environments where this is useful too.

drj