rust/src/libstd/cmp.rs
2013-01-29 16:54:55 -05:00

67 lines
1.8 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.
#[forbid(deprecated_mode)];
//! Additional general-purpose comparison functionality.
use core::f32;
use core::f64;
use core::float;
const fuzzy_epsilon: float = 1.0e-6;
pub trait FuzzyEq {
pure fn fuzzy_eq(&self, other: &self) -> bool;
pure fn fuzzy_eq_eps(&self, other: &self, epsilon: &self) -> bool;
}
impl float: FuzzyEq {
pure fn fuzzy_eq(&self, other: &float) -> bool {
self.fuzzy_eq_eps(other, &fuzzy_epsilon)
}
pure fn fuzzy_eq_eps(&self, other: &float, epsilon: &float) -> bool {
float::abs(*self - *other) < *epsilon
}
}
impl f32: FuzzyEq {
pure fn fuzzy_eq(&self, other: &f32) -> bool {
self.fuzzy_eq_eps(other, &(fuzzy_epsilon as f32))
}
pure fn fuzzy_eq_eps(&self, other: &f32, epsilon: &f32) -> bool {
f32::abs(*self - *other) < *epsilon
}
}
impl f64: FuzzyEq {
pure fn fuzzy_eq(&self, other: &f64) -> bool {
self.fuzzy_eq_eps(other, &(fuzzy_epsilon as f64))
}
pure fn fuzzy_eq_eps(&self, other: &f64, epsilon: &f64) -> bool {
f64::abs(*self - *other) < *epsilon
}
}
#[test]
fn test_fuzzy_equals() {
assert (&1.0).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 (&1.2).fuzzy_eq_eps(&0.9, &0.5);
assert !(&1.5).fuzzy_eq_eps(&0.9, &0.5);
}