f64 only mode

[Kezii]

I'm using rhai as a glorified calculator inside a somewhat popular telegram bot (#69 ), the problem is that the hard distinction between integer and float types that rhai has, is making the language hard to use

It would be cool to have an option where you can make 10 / 9 or sqrt(2) and obtain the correct floating point result instead of an 1 or an error
I suppose this can be solved by having an option to treat all literals as f64 and parsing them as that
Using f64 exclusively does not give immediate problems (or at all) as noted in the lua documentation https://www.lua.org/pil/2.3.html

[schungx]

It is not as simple as just parsing all integer literals as f64 because a lot of built-in functions return integer values, such as len.

INT is just about the most basic type in Rhai; I'm not sure whether it is possible to do away with it.

It is possible, however, to overload the division operator as well as certain math functions. For example, we can always overload / to do floating point instead when being passed two integers. We can define sqrt(INT) and pass it to sqrt(f64).

The user, however, may be surprised that a division turns the number into floating-point.

[schungx]

Alternatively, we can allow you to set a mapper function into the Engine, such that you can convert any Token from the tokenizer into something else. For example, you can register a closure that turns any Token::IntegerConstant into Token::FloatConstant and that should provide you with exactly what you ask for.

Internall, Rhai already has facilities to set such a mapper function; it is just not exposed publicly.

[Kezii]

Thanks for the answer
Yeah just changing the parsing of the literals is enough, that's the bulk of the usability problem, casting the result of len() is less disruptive than remembering to put a . after every constant
I guess that the mapper function should work

[schungx]

You can pull from https://github.com/rhaiscript/rhai and get the version with Engine::on_parse_token which allows you to remap tokens.

Remember to pull in the internals feature.

[Kezii]

that works perfectly, thanks