malachite-float 0.10.0

The arbitrary-precision floating-point type Float, with efficient algorithms partially derived from MPFR.
Documentation 
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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.

use crate::test_util::common::rug_float_significant_bits;
use core::cmp::Ordering;
use malachite_base::num::conversion::traits::ExactFrom;
use malachite_q::Rational;
use rug::float::Round;
use rug::ops::AssignRound;

pub fn rug_exp_prec_round(x: &rug::Float, prec: u64, rm: Round) -> (rug::Float, Ordering) {
    let mut e = rug::Float::with_val(u32::exact_from(prec), 0);
    let o = e.assign_round(x.exp_ref(), rm);
    (e, o)
}

pub fn rug_exp_prec(x: &rug::Float, prec: u64) -> (rug::Float, Ordering) {
    rug_exp_prec_round(x, prec, Round::Nearest)
}

// Computes exp(x) for a Rational x, rounded to `prec` with mode `rm`. The Rational is first
// converted to a rug `Float` with `prec + 128` bits; since the finite exp range has |x| < 2^30,
// that is enough extra precision that the result rounds the same as the exact exp(x) for all
// property test inputs (it would only differ if exp(x) were within ~2^-98 of a rounding boundary).
pub fn rug_exp_rational_prec_round(x: &Rational, prec: u64, rm: Round) -> (rug::Float, Ordering) {
    let rx = rug::Float::with_val(u32::exact_from(prec + 128), rug::Rational::exact_from(x));
    let mut e = rug::Float::with_val(u32::exact_from(prec), 0);
    let o = e.assign_round(rx.exp_ref(), rm);
    (e, o)
}

pub fn rug_exp_rational_prec(x: &Rational, prec: u64) -> (rug::Float, Ordering) {
    rug_exp_rational_prec_round(x, prec, Round::Nearest)
}

pub fn rug_exp_round(x: &rug::Float, rm: Round) -> (rug::Float, Ordering) {
    rug_exp_prec_round(x, rug_float_significant_bits(x), rm)
}

pub fn rug_exp(x: &rug::Float) -> rug::Float {
    rug_exp_prec_round(x, rug_float_significant_bits(x), Round::Nearest).0
}