Why should we use lua_pushinteger()?

Question

The current versions of Lua don't support integer numbers, only floats. (With the upcoming 5.3 this is changing, but let's ignore this.)

So, my question is: what use there is in lua_pushinteger()? If the numbers get cast into a float, why not use lua_pushnumber() directly?

(Please don't answer "for future compatibility with 5.3", which is a good answer for today but is an answer that otherwise doesn't satisfy my curisoty: integer support wasn't expected in the old days. I want to know the reason lua_pushinteger() was introduced in the first place, not apologetic in hindsight.)

The answer your propose is the one that is correct, I used to ignore *integer and *unsigned 5.3 in my code, but now I see, the *integer and *unsigned code was introduced to ease us into 5.3. — user1095108, Jun 12 '14 at 13:38
Since using number we get ".0" after every integer in the lua script — Epirocks, Mar 21 '23 at 14:15

score 5 · Accepted Answer · answered Jun 12 '14 at 14:27

5

The explicit handling of integers in the API was introduced for documentation, performance, and correctness.

Concentrating the handling of integers explicitly inside the API allows the core to use the best conversion to and from floats; in some platforms, this can be costly if done naively. It also allows the core to check for overflow, though Lua 5.1 and 5.2 did not check this.

answered Jun 12 '14 at 14:27

lhf

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Thanks. I have a small question: I understand what "documentation" and "performance" mean here, but what do you mean by "correctness"? Since Lua doesn't check for overflow, how else can a cast from int to float be incorrect? – Niccolo M. Jun 12 '14 at 17:51

Why should we use lua_pushinteger()?

1 Answers1