rust/src/libstd/cmp.rs
2013-03-29 16:39:08 -07:00

103 lines
2.8 KiB
Rust

// Copyright 2012-2013 The Rust Project Developers. See the
// COPYRIGHT file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Additional general-purpose comparison functionality.
use core::f32;
use core::f64;
use core::float;
pub static FUZZY_EPSILON: float = 1.0e-6;
pub trait FuzzyEq<Eps> {
fn fuzzy_eq(&self, other: &Self) -> bool;
fn fuzzy_eq_eps(&self, other: &Self, epsilon: &Eps) -> bool;
}
impl FuzzyEq<float> for float {
fn fuzzy_eq(&self, other: &float) -> bool {
self.fuzzy_eq_eps(other, &FUZZY_EPSILON)
}
fn fuzzy_eq_eps(&self, other: &float, epsilon: &float) -> bool {
float::abs(*self - *other) < *epsilon
}
}
impl FuzzyEq<f32> for f32 {
fn fuzzy_eq(&self, other: &f32) -> bool {
self.fuzzy_eq_eps(other, &(FUZZY_EPSILON as f32))
}
fn fuzzy_eq_eps(&self, other: &f32, epsilon: &f32) -> bool {
f32::abs(*self - *other) < *epsilon
}
}
impl FuzzyEq<f64> for f64 {
fn fuzzy_eq(&self, other: &f64) -> bool {
self.fuzzy_eq_eps(other, &(FUZZY_EPSILON as f64))
}
fn fuzzy_eq_eps(&self, other: &f64, epsilon: &f64) -> bool {
f64::abs(*self - *other) < *epsilon
}
}
#[test]
fn test_fuzzy_equals() {
assert!((&1.0f).fuzzy_eq(&1.0));
assert!((&1.0f32).fuzzy_eq(&1.0f32));
assert!((&1.0f64).fuzzy_eq(&1.0f64));
}
#[test]
fn test_fuzzy_eq_eps() {
assert!((&1.2f).fuzzy_eq_eps(&0.9, &0.5));
assert!(!(&1.5f).fuzzy_eq_eps(&0.9, &0.5));
}
#[test]
mod test_complex{
use cmp::*;
struct Complex { r: float, i: float }
impl FuzzyEq<float> for Complex {
fn fuzzy_eq(&self, other: &Complex) -> bool {
self.fuzzy_eq_eps(other, &FUZZY_EPSILON)
}
fn fuzzy_eq_eps(&self, other: &Complex,
epsilon: &float) -> bool {
self.r.fuzzy_eq_eps(&other.r, epsilon) &&
self.i.fuzzy_eq_eps(&other.i, epsilon)
}
}
#[test]
fn test_fuzzy_equals() {
let a = Complex {r: 0.9, i: 0.9};
let b = Complex {r: 0.9, i: 0.9};
assert!((a.fuzzy_eq(&b)));
}
#[test]
fn test_fuzzy_eq_eps() {
let other = Complex {r: 0.9, i: 0.9};
assert!((&Complex {r: 0.9, i: 1.2}).fuzzy_eq_eps(&other, &0.5));
assert!((&Complex {r: 1.2, i: 0.9}).fuzzy_eq_eps(&other, &0.5));
assert!(!(&Complex {r: 0.9, i: 1.5}).fuzzy_eq_eps(&other, &0.5));
assert!(!(&Complex {r: 1.5, i: 0.9}).fuzzy_eq_eps(&other, &0.5));
}
}