Re: Are automatic coercions ever going away?

[Sean Conner <sean@...>]

It was thus said that the Great Coroutines once stated:
> On Fri, Aug 1, 2014 at 12:57 PM, Sean Conner <sean@conman.org> wrote:
> 
> >   One situation I hit in C was the following:
> >
> >         static int foobar___index(lua_State *L)
> >         {
> >           foobar__s *foo = luaL_checkudata(L,1,TYPE_FOO);
> >
> >           if (lua_isstring(L,2))
> >             ...
> >           else if (lua_isnumber(L,2))
> >             ...
> >         }
> >
> > Odd bugs until I actually read the description for lua_isstring():
> >
> >         Returns 1 if the value at the given index is a string or a number
> >         (which is always convertible to a string), and 0 otherwise.
> >
> > lua_to[l]string() will do a convertion if the target is a number.  I'm sure
> > it's convenient in some cases, but not in others.
> >
> >   Oddly enough, I dont' have an issue with lua_isboolean() or
> > lua_toboolean() even though they do a conversion as well (nil or false as
> > false, anything else is true).
> 
> I think I've just made it a habit to use luaL_checktype(), I can see
> how that might be confusing to use the is<type>() functions, though

  luaL_checktype() throws an error though.  Here, I'm checking the same
index for different types.  I suppose I could have done:

	if (lua_type(L,2) == LUA_TNUMBER)
	  ...
	else if (lua_type(L,2) == LUA_TSTRING)
	  ...

  -spc