use crate::Rational;
use malachite_base::num::arithmetic::traits::DivRound;
use malachite_base::num::conversion::traits::{ConvertibleFrom, RoundingFrom};
use malachite_base::rounding_modes::RoundingMode;
use malachite_nz::integer::Integer;
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct IntegerFromRationalError;
impl TryFrom<Rational> for Integer {
type Error = IntegerFromRationalError;
/// Converts a [`Rational`] to an [`Integer`](malachite_nz::integer::Integer), taking the
/// [`Rational`] by value. If the [`Rational`] is not an integer, an error is returned.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_nz::integer::Integer;
/// use malachite_q::conversion::integer_from_rational::IntegerFromRationalError;
/// use malachite_q::Rational;
///
/// assert_eq!(Integer::try_from(Rational::from(123)).unwrap(), 123);
/// assert_eq!(Integer::try_from(Rational::from(-123)).unwrap(), -123);
/// assert_eq!(
/// Integer::try_from(Rational::from_signeds(22, 7)),
/// Err(IntegerFromRationalError)
/// );
/// ```
fn try_from(x: Rational) -> Result<Integer, Self::Error> {
if x.denominator == 1u32 {
Ok(Integer::from_sign_and_abs(x.sign, x.numerator))
} else {
Err(IntegerFromRationalError)
}
}
}
impl<'a> TryFrom<&'a Rational> for Integer {
type Error = IntegerFromRationalError;
/// Converts a [`Rational`] to an [`Integer`](malachite_nz::integer::Integer), taking the
/// [`Rational`] by reference. If the [`Rational`] is not an integer, an error is returned.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `x.significant_bits()`.
///
/// # Examples
/// ```
/// use malachite_nz::integer::Integer;
/// use malachite_q::conversion::integer_from_rational::IntegerFromRationalError;
/// use malachite_q::Rational;
///
/// assert_eq!(Integer::try_from(&Rational::from(123)).unwrap(), 123);
/// assert_eq!(Integer::try_from(&Rational::from(-123)).unwrap(), -123);
/// assert_eq!(
/// Integer::try_from(&Rational::from_signeds(22, 7)),
/// Err(IntegerFromRationalError)
/// );
/// ```
fn try_from(x: &Rational) -> Result<Integer, Self::Error> {
if x.denominator == 1u32 {
Ok(Integer::from_sign_and_abs_ref(x.sign, &x.numerator))
} else {
Err(IntegerFromRationalError)
}
}
}
impl<'a> ConvertibleFrom<&'a Rational> for Integer {
/// Determines whether a [`Rational`] can be converted to an
/// [`Integer`](malachite_nz::integer::Integer), taking the [`Rational`] by reference.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::conversion::traits::ConvertibleFrom;
/// use malachite_nz::integer::Integer;
/// use malachite_q::Rational;
///
/// assert_eq!(Integer::convertible_from(&Rational::from(123)), true);
/// assert_eq!(Integer::convertible_from(&Rational::from(-123)), true);
/// assert_eq!(Integer::convertible_from(&Rational::from_signeds(22, 7)), false);
/// ```
#[inline]
fn convertible_from(x: &Rational) -> bool {
x.denominator == 1u32
}
}
impl RoundingFrom<Rational> for Integer {
/// Converts a [`Rational`] to an [`Integer`](malachite_nz::integer::Integer), using a
/// specified [`RoundingMode`](malachite_base::rounding_modes::RoundingMode) and taking the
/// [`Rational`] by value.
///
/// # Worst-case complexity
/// $T(n) = O(n \log n \log\log n)$
///
/// $M(n) = O(n \log n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `x.significant_bits()`.
///
/// # Panics
/// Panics if the [`Rational`] is not an integer and `rm` is `Exact`.
///
/// # Examples
/// ```
/// use malachite_base::num::conversion::traits::RoundingFrom;
/// use malachite_base::rounding_modes::RoundingMode;
/// use malachite_nz::integer::Integer;
/// use malachite_q::Rational;
///
/// assert_eq!(Integer::rounding_from(Rational::from(123), RoundingMode::Exact), 123);
/// assert_eq!(Integer::rounding_from(Rational::from(-123), RoundingMode::Exact), -123);
///
/// assert_eq!(Integer::rounding_from(Rational::from_signeds(22, 7), RoundingMode::Floor), 3);
/// assert_eq!(Integer::rounding_from(Rational::from_signeds(22, 7), RoundingMode::Down), 3);
/// assert_eq!(
/// Integer::rounding_from(Rational::from_signeds(22, 7), RoundingMode::Ceiling),
/// 4
/// );
/// assert_eq!(Integer::rounding_from(Rational::from_signeds(22, 7), RoundingMode::Up), 4);
/// assert_eq!(
/// Integer::rounding_from(Rational::from_signeds(22, 7), RoundingMode::Nearest),
/// 3
/// );
///
/// assert_eq!(
/// Integer::rounding_from(Rational::from_signeds(-22, 7), RoundingMode::Floor),
/// -4
/// );
/// assert_eq!(Integer::rounding_from(Rational::from_signeds(-22, 7), RoundingMode::Down), -3);
/// assert_eq!(
/// Integer::rounding_from(Rational::from_signeds(-22, 7), RoundingMode::Ceiling),
/// -3
/// );
/// assert_eq!(Integer::rounding_from(Rational::from_signeds(-22, 7), RoundingMode::Up), -4);
/// assert_eq!(
/// Integer::rounding_from(Rational::from_signeds(-22, 7), RoundingMode::Nearest),
/// -3
/// );
/// ```
fn rounding_from(x: Rational, rm: RoundingMode) -> Integer {
Integer::from_sign_and_abs(
x.sign,
x.numerator
.div_round(x.denominator, if x.sign { rm } else { -rm }),
)
}
}
impl<'a> RoundingFrom<&'a Rational> for Integer {
/// Converts a [`Rational`] to an [`Integer`](malachite_nz::integer::Integer), using a
/// specified [`RoundingMode`](malachite_base::rounding_modes::RoundingMode) and taking the
/// [`Rational`] by reference.
///
/// # Worst-case complexity
/// $T(n) = O(n \log n \log\log n)$
///
/// $M(n) = O(n \log n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `x.significant_bits()`.
///
/// # Panics
/// Panics if the [`Rational`] is not an integer and `rm` is `Exact`.
///
/// # Examples
/// ```
/// use malachite_base::num::conversion::traits::RoundingFrom;
/// use malachite_base::rounding_modes::RoundingMode;
/// use malachite_nz::integer::Integer;
/// use malachite_q::Rational;
///
/// assert_eq!(Integer::rounding_from(&Rational::from(123), RoundingMode::Exact), 123);
/// assert_eq!(Integer::rounding_from(&Rational::from(-123), RoundingMode::Exact), -123);
///
/// assert_eq!(Integer::rounding_from(&Rational::from_signeds(22, 7), RoundingMode::Floor), 3);
/// assert_eq!(Integer::rounding_from(&Rational::from_signeds(22, 7), RoundingMode::Down), 3);
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(22, 7), RoundingMode::Ceiling),
/// 4
/// );
/// assert_eq!(Integer::rounding_from(&Rational::from_signeds(22, 7), RoundingMode::Up), 4);
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(22, 7), RoundingMode::Nearest),
/// 3
/// );
///
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(-22, 7), RoundingMode::Floor),
/// -4
/// );
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(-22, 7), RoundingMode::Down),
/// -3
/// );
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(-22, 7), RoundingMode::Ceiling),
/// -3
/// );
/// assert_eq!(Integer::rounding_from(&Rational::from_signeds(-22, 7), RoundingMode::Up), -4);
/// assert_eq!(
/// Integer::rounding_from(&Rational::from_signeds(-22, 7), RoundingMode::Nearest),
/// -3
/// );
/// ```
fn rounding_from(x: &Rational, rm: RoundingMode) -> Integer {
Integer::from_sign_and_abs(
x.sign,
(&x.numerator).div_round(&x.denominator, if x.sign { rm } else { -rm }),
)
}
}