Re: Lua 5.3 work1 Considering math.isinteger or type()

[Roberto Ierusalimschy <roberto@...>]

> On Wed, Jul 17, 2013 at 10:10 AM, David Demelier
> <demelier.david@gmail.com>wrote:
> 
> > type(10) -> "number", "integer"
> > type(10.0) -> "number", "float"
> >
> > This is not a bad idea, it will not break compatibility but adds a
> > second feature to determine the actual type of the integer.

I do not think it is a good idea. If something is an integer, it must
be a number, so the first result is useless when you want the second.
And to simply check whether something is an integer you will need extra
local variables or 'select', to access that second result.


> (Saying this because string.gsub is always biting me this way)

That was not a good idea, either :)

We moved that functionality to a new function, debug.subtype, that
returns the following: integer, float, Cfunction, Luafunction,
lightudata, fulludata, string, boolean, nil, table, and thread.

Some of that functionality may not be strictly "debug", but anyway
it is something you should not be using every day, and we could not
find a better place to put that function; it may move to the global
space...

(In an ideal world, probably we should have a library with those
functions we do not use every day (maybe with rawget, rawset,
getmetatable, setmetatable, collectgarbage, and some others), but I do
not think the change is worth the trouble. Just imagine the endless
discussions about what functions should go there...)

-- Roberto