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Add doctests to FloatCore

This commit is contained in:
Josh Stone 2018-02-27 22:12:37 -08:00
parent ec3cd50f3d
commit aa9ceba628
1 changed files with 499 additions and 5 deletions
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504
src/float.rs
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@ -12,48 +12,230 @@ use {Num, NumCast};
/// This trait implements a subset of the `Float` trait.
pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Returns positive infinity.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::infinity() == x);
/// }
///
/// check(f32::INFINITY);
/// check(f64::INFINITY);
/// ```
fn infinity() -> Self;
/// Returns negative infinity.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::neg_infinity() == x);
/// }
///
/// check(f32::NEG_INFINITY);
/// check(f64::NEG_INFINITY);
/// ```
fn neg_infinity() -> Self;
/// Returns NaN.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
///
/// fn check<T: FloatCore>() {
/// let n = T::nan();
/// assert!(n != n);
/// }
///
/// check::<f32>();
/// check::<f64>();
/// ```
fn nan() -> Self;
/// Returns `-0.0`.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(n: T) {
/// let z = T::neg_zero();
/// assert!(z.is_zero());
/// assert!(T::one() / z == n);
/// }
///
/// check(f32::NEG_INFINITY);
/// check(f64::NEG_INFINITY);
/// ```
fn neg_zero() -> Self;
/// Returns the smallest finite value that this type can represent.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::min_value() == x);
/// }
///
/// check(f32::MIN);
/// check(f64::MIN);
/// ```
fn min_value() -> Self;
/// Returns the smallest positive, normalized value that this type can represent.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::min_positive_value() == x);
/// }
///
/// check(f32::MIN_POSITIVE);
/// check(f64::MIN_POSITIVE);
/// ```
fn min_positive_value() -> Self;
/// Returns epsilon, a small positive value.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::epsilon() == x);
/// }
///
/// check(f32::EPSILON);
/// check(f64::EPSILON);
/// ```
fn epsilon() -> Self;
/// Returns the largest finite value that this type can represent.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T) {
/// assert!(T::max_value() == x);
/// }
///
/// check(f32::MAX);
/// check(f64::MAX);
/// ```
fn max_value() -> Self;
/// Returns `true` if the number is NaN.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_nan() == p);
/// }
///
/// check(f32::NAN, true);
/// check(f32::INFINITY, false);
/// check(f64::NAN, true);
/// check(0.0f64, false);
/// ```
#[inline]
fn is_nan(self) -> bool {
self != self
}
/// Returns `true` if the number is infinite.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_infinite() == p);
/// }
///
/// check(f32::INFINITY, true);
/// check(f32::NEG_INFINITY, true);
/// check(f32::NAN, false);
/// check(f64::INFINITY, true);
/// check(f64::NEG_INFINITY, true);
/// check(0.0f64, false);
/// ```
#[inline]
fn is_infinite(self) -> bool {
self == Self::infinity() || self == Self::neg_infinity()
}
/// Returns `true` if the number is neither infinite or NaN.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_finite() == p);
/// }
///
/// check(f32::INFINITY, false);
/// check(f32::MAX, true);
/// check(f64::NEG_INFINITY, false);
/// check(f64::MIN_POSITIVE, true);
/// check(f64::NAN, false);
/// ```
#[inline]
fn is_finite(self) -> bool {
!(self.is_nan() || self.is_infinite())
}
/// Returns `true` if the number is neither zero, infinite, subnormal or NaN.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_normal() == p);
/// }
///
/// check(f32::INFINITY, false);
/// check(f32::MAX, true);
/// check(f64::NEG_INFINITY, false);
/// check(f64::MIN_POSITIVE, true);
/// check(0.0f64, false);
/// ```
#[inline]
fn is_normal(self) -> bool {
self.classify() == FpCategory::Normal
@ -62,9 +244,49 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Returns the floating point category of the number. If only one property
/// is going to be tested, it is generally faster to use the specific
/// predicate instead.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
/// use std::num::FpCategory;
///
/// fn check<T: FloatCore>(x: T, c: FpCategory) {
/// assert!(x.classify() == c);
/// }
///
/// check(f32::INFINITY, FpCategory::Infinite);
/// check(f32::MAX, FpCategory::Normal);
/// check(f64::NAN, FpCategory::Nan);
/// check(f64::MIN_POSITIVE, FpCategory::Normal);
/// check(f64::MIN_POSITIVE / 2.0, FpCategory::Subnormal);
/// check(0.0f64, FpCategory::Zero);
/// ```
fn classify(self) -> FpCategory;
/// Returns the largest integer less than or equal to a number.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.floor() == y);
/// }
///
/// check(f32::INFINITY, f32::INFINITY);
/// check(0.9f32, 0.0);
/// check(1.0f32, 1.0);
/// check(1.1f32, 1.0);
/// check(-0.0f64, 0.0);
/// check(-0.9f64, -1.0);
/// check(-1.0f64, -1.0);
/// check(-1.1f64, -2.0);
/// check(f64::MIN, f64::MIN);
/// ```
#[inline]
fn floor(self) -> Self {
let f = self.fract();
@ -78,6 +300,27 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Returns the smallest integer greater than or equal to a number.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.ceil() == y);
/// }
///
/// check(f32::INFINITY, f32::INFINITY);
/// check(0.9f32, 1.0);
/// check(1.0f32, 1.0);
/// check(1.1f32, 2.0);
/// check(-0.0f64, 0.0);
/// check(-0.9f64, -0.0);
/// check(-1.0f64, -1.0);
/// check(-1.1f64, -1.0);
/// check(f64::MIN, f64::MIN);
/// ```
#[inline]
fn ceil(self) -> Self {
let f = self.fract();
@ -91,6 +334,26 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Returns the nearest integer to a number. Round half-way cases away from `0.0`.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.round() == y);
/// }
///
/// check(f32::INFINITY, f32::INFINITY);
/// check(0.4f32, 0.0);
/// check(0.5f32, 1.0);
/// check(0.6f32, 1.0);
/// check(-0.4f64, 0.0);
/// check(-0.5f64, -1.0);
/// check(-0.6f64, -1.0);
/// check(f64::MIN, f64::MIN);
/// ```
#[inline]
fn round(self) -> Self {
let one = Self::one();
@ -114,6 +377,27 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Return the integer part of a number.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.trunc() == y);
/// }
///
/// check(f32::INFINITY, f32::INFINITY);
/// check(0.9f32, 0.0);
/// check(1.0f32, 1.0);
/// check(1.1f32, 1.0);
/// check(-0.0f64, 0.0);
/// check(-0.9f64, -0.0);
/// check(-1.0f64, -1.0);
/// check(-1.1f64, -1.0);
/// check(f64::MIN, f64::MIN);
/// ```
#[inline]
fn trunc(self) -> Self {
let f = self.fract();
@ -125,6 +409,27 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Returns the fractional part of a number.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.fract() == y);
/// }
///
/// check(f32::MAX, 0.0);
/// check(0.75f32, 0.75);
/// check(1.0f32, 0.0);
/// check(1.25f32, 0.25);
/// check(-0.0f64, 0.0);
/// check(-0.75f64, -0.75);
/// check(-1.0f64, 0.0);
/// check(-1.25f64, -0.25);
/// check(f64::MIN, 0.0);
/// ```
#[inline]
fn fract(self) -> Self {
if self.is_zero() {
@ -136,6 +441,24 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Computes the absolute value of `self`. Returns `FloatCore::nan()` if the
/// number is `FloatCore::nan()`.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.abs() == y);
/// }
///
/// check(f32::INFINITY, f32::INFINITY);
/// check(1.0f32, 1.0);
/// check(0.0f64, 0.0);
/// check(-0.0f64, 0.0);
/// check(-1.0f64, 1.0);
/// check(f64::MIN, f64::MAX);
/// ```
#[inline]
fn abs(self) -> Self {
if self.is_sign_positive() {
@ -152,6 +475,24 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// - `1.0` if the number is positive, `+0.0` or `FloatCore::infinity()`
/// - `-1.0` if the number is negative, `-0.0` or `FloatCore::neg_infinity()`
/// - `FloatCore::nan()` if the number is `FloatCore::nan()`
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.signum() == y);
/// }
///
/// check(f32::INFINITY, 1.0);
/// check(3.0f32, 1.0);
/// check(0.0f32, 1.0);
/// check(-0.0f64, -1.0);
/// check(-3.0f64, -1.0);
/// check(f64::MIN, -1.0);
/// ```
#[inline]
fn signum(self) -> Self {
if self.is_nan() {
@ -164,14 +505,54 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Returns `true` if `self` is positive, including `+0.0` and
/// `FloatCore::infinity()`.
/// `FloatCore::infinity()`, and with newer versions of Rust
/// even `FloatCore::nan()`.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_sign_positive() == p);
/// }
///
/// check(f32::INFINITY, true);
/// check(f32::MAX, true);
/// check(0.0f32, true);
/// check(-0.0f64, false);
/// check(f64::NEG_INFINITY, false);
/// check(f64::MIN_POSITIVE, true);
/// check(-f64::NAN, false);
/// ```
#[inline]
fn is_sign_positive(self) -> bool {
!self.is_sign_negative()
}
/// Returns `true` if `self` is negative, including `-0.0` and
/// `FloatCore::neg_infinity()`.
/// `FloatCore::neg_infinity()`, and with newer versions of Rust
/// even `-FloatCore::nan()`.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, p: bool) {
/// assert!(x.is_sign_negative() == p);
/// }
///
/// check(f32::INFINITY, false);
/// check(f32::MAX, false);
/// check(0.0f32, false);
/// check(-0.0f64, true);
/// check(f64::NEG_INFINITY, true);
/// check(f64::MIN_POSITIVE, false);
/// check(f64::NAN, false);
/// ```
#[inline]
fn is_sign_negative(self) -> bool {
let (_, _, sign) = self.integer_decode();
@ -181,6 +562,22 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Returns the minimum of the two numbers.
///
/// If one of the arguments is NaN, then the other argument is returned.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T, min: T) {
/// assert!(x.min(y) == min);
/// }
///
/// check(1.0f32, 2.0, 1.0);
/// check(f32::NAN, 2.0, 2.0);
/// check(1.0f64, -2.0, -2.0);
/// check(1.0f64, f64::NAN, 1.0);
/// ```
#[inline]
fn min(self, other: Self) -> Self {
if self.is_nan() {
@ -195,6 +592,22 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Returns the maximum of the two numbers.
///
/// If one of the arguments is NaN, then the other argument is returned.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T, min: T) {
/// assert!(x.max(y) == min);
/// }
///
/// check(1.0f32, 2.0, 2.0);
/// check(1.0f32, f32::NAN, 1.0);
/// check(-1.0f64, 2.0, 2.0);
/// check(-1.0f64, f64::NAN, -1.0);
/// ```
#[inline]
fn max(self, other: Self) -> Self {
if self.is_nan() {
@ -207,6 +620,23 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Returns the reciprocal (multiplicative inverse) of the number.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, y: T) {
/// assert!(x.recip() == y);
/// assert!(y.recip() == x);
/// }
///
/// check(f32::INFINITY, 0.0);
/// check(2.0f32, 0.5);
/// check(-0.25f64, -4.0);
/// check(-0.0f64, f64::NEG_INFINITY);
/// ```
#[inline]
fn recip(self) -> Self {
Self::one() / self
@ -215,6 +645,22 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
/// Raise a number to an integer power.
///
/// Using this function is generally faster than using `powf`
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
///
/// fn check<T: FloatCore>(x: T, exp: i32, powi: T) {
/// assert!(x.powi(exp) == powi);
/// }
///
/// check(9.0f32, 2, 81.0);
/// check(1.0f32, -2, 1.0);
/// check(10.0f64, 20, 1e20);
/// check(4.0f64, -2, 0.0625);
/// check(-1.0f64, std::i32::MIN, 1.0);
/// ```
#[inline]
fn powi(mut self, mut exp: i32) -> Self {
if exp < 0 {
@ -226,14 +672,64 @@ pub trait FloatCore: Num + NumCast + Neg<Output = Self> + PartialOrd + Copy {
}
/// Converts to degrees, assuming the number is in radians.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(rad: T, deg: T) {
/// assert!(rad.to_degrees() == deg);
/// }
///
/// check(0.0f32, 0.0);
/// check(f32::consts::PI, 180.0);
/// check(f64::consts::FRAC_PI_4, 45.0);
/// check(f64::INFINITY, f64::INFINITY);
/// ```
fn to_degrees(self) -> Self;
/// Converts to radians, assuming the number is in degrees.
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(deg: T, rad: T) {
/// assert!(deg.to_radians() == rad);
/// }
///
/// check(0.0f32, 0.0);
/// check(180.0, f32::consts::PI);
/// check(45.0, f64::consts::FRAC_PI_4);
/// check(f64::INFINITY, f64::INFINITY);
/// ```
fn to_radians(self) -> Self;
/// Returns the mantissa, base 2 exponent, and sign as integers, respectively.
/// The original number can be recovered by `sign * mantissa * 2 ^ exponent`.
/// The floating point encoding is documented in the [Reference][floating-point].
///
/// # Examples
///
/// ```
/// use num_traits::float::FloatCore;
/// use std::{f32, f64};
///
/// fn check<T: FloatCore>(x: T, m: u64, e: i16, s:i8) {
/// let (mantissa, exponent, sign) = x.integer_decode();
/// assert_eq!(mantissa, m);
/// assert_eq!(exponent, e);
/// assert_eq!(sign, s);
/// }
///
/// check(2.0f32, 1 << 23, -22, 1);
/// check(-2.0f32, 1 << 23, -22, -1);
/// check(f32::INFINITY, 1 << 23, 105, 1);
/// check(f64::NEG_INFINITY, 1 << 52, 972, -1);
/// ```
fn integer_decode(self) -> (u64, i16, i8);
}
@ -1275,7 +1771,6 @@ pub trait Float
/// Returns the mantissa, base 2 exponent, and sign as integers, respectively.
/// The original number can be recovered by `sign * mantissa * 2 ^ exponent`.
/// The floating point encoding is documented in the [Reference][floating-point].
///
/// ```
/// use num_traits::Float;
@ -1293,7 +1788,6 @@ pub trait Float
///
/// assert!(abs_difference < 1e-10);
/// ```
/// [floating-point]: ../../../../../reference.html#machine-types
fn integer_decode(self) -> (u64, i16, i8);
}