luaur-code-gen 0.1.0

extern crate alloc;

use alloc::format;
use alloc::string::String;

pub(crate) fn format_g(v: f64, precision: i32) -> String {
    if v.is_nan() {
        return String::from("nan");
    }

    if v.is_infinite() {
        return if v.is_sign_negative() {
            String::from("-inf")
        } else {
            String::from("inf")
        };
    }

    if v == 0.0 {
        return if v.is_sign_negative() {
            String::from("-0")
        } else {
            String::from("0")
        };
    }

    let sci = format!("{:.*e}", (precision - 1).max(0) as usize, v);
    let exp: i32 = sci[sci.find('e').map(|i| i + 1).unwrap_or(sci.len())..]
        .parse()
        .unwrap_or(0);

    if exp >= -4 && exp < precision {
        let frac = (precision - 1 - exp).max(0) as usize;
        let mut s = format!("{:.*}", frac, v);

        if s.contains('.') {
            while s.ends_with('0') {
                s.pop();
            }
            if s.ends_with('.') {
                s.pop();
            }
        }

        s
    } else {
        let (mant, exp_part) = sci.split_once('e').unwrap_or((sci.as_str(), "0"));
        let mut m = String::from(mant);

        if m.contains('.') {
            while m.ends_with('0') {
                m.pop();
            }
            if m.ends_with('.') {
                m.pop();
            }
        }

        let e: i32 = exp_part.parse().unwrap_or(0);
        format!("{}e{}{:02}", m, if e < 0 { "-" } else { "+" }, e.abs())
    }
}