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Diffstat (limited to 'ctr-std/src/num.rs')
| -rw-r--r-- | ctr-std/src/num.rs | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/ctr-std/src/num.rs b/ctr-std/src/num.rs new file mode 100644 index 0000000..d1c2fc3 --- /dev/null +++ b/ctr-std/src/num.rs @@ -0,0 +1,293 @@ +// Copyright 2012-2014 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 functionality for numerics. +//! +//! This module provides some extra types that are useful when doing numerical +//! work. See the individual documentation for each piece for more information. + +#![stable(feature = "rust1", since = "1.0.0")] +#![allow(missing_docs)] + +#[stable(feature = "rust1", since = "1.0.0")] +#[allow(deprecated)] +pub use core::num::{Zero, One}; +#[stable(feature = "rust1", since = "1.0.0")] +pub use core::num::{FpCategory, ParseIntError, ParseFloatError, TryFromIntError}; +#[stable(feature = "rust1", since = "1.0.0")] +pub use core::num::Wrapping; + +#[cfg(test)] use fmt; +#[cfg(test)] use ops::{Add, Sub, Mul, Div, Rem}; + +/// Helper function for testing numeric operations +#[cfg(test)] +pub fn test_num<T>(ten: T, two: T) where + T: PartialEq + + Add<Output=T> + Sub<Output=T> + + Mul<Output=T> + Div<Output=T> + + Rem<Output=T> + fmt::Debug + + Copy +{ + assert_eq!(ten.add(two), ten + two); + assert_eq!(ten.sub(two), ten - two); + assert_eq!(ten.mul(two), ten * two); + assert_eq!(ten.div(two), ten / two); + assert_eq!(ten.rem(two), ten % two); +} + +#[cfg(test)] +mod tests { + use u8; + use u16; + use u32; + use u64; + use usize; + use ops::Mul; + + #[test] + fn test_saturating_add_uint() { + use usize::MAX; + assert_eq!(3_usize.saturating_add(5_usize), 8_usize); + assert_eq!(3_usize.saturating_add(MAX-1), MAX); + assert_eq!(MAX.saturating_add(MAX), MAX); + assert_eq!((MAX-2).saturating_add(1), MAX-1); + } + + #[test] + fn test_saturating_sub_uint() { + use usize::MAX; + assert_eq!(5_usize.saturating_sub(3_usize), 2_usize); + assert_eq!(3_usize.saturating_sub(5_usize), 0_usize); + assert_eq!(0_usize.saturating_sub(1_usize), 0_usize); + assert_eq!((MAX-1).saturating_sub(MAX), 0); + } + + #[test] + fn test_saturating_add_int() { + use isize::{MIN,MAX}; + assert_eq!(3i32.saturating_add(5), 8); + assert_eq!(3isize.saturating_add(MAX-1), MAX); + assert_eq!(MAX.saturating_add(MAX), MAX); + assert_eq!((MAX-2).saturating_add(1), MAX-1); + assert_eq!(3i32.saturating_add(-5), -2); + assert_eq!(MIN.saturating_add(-1), MIN); + assert_eq!((-2isize).saturating_add(-MAX), MIN); + } + + #[test] + fn test_saturating_sub_int() { + use isize::{MIN,MAX}; + assert_eq!(3i32.saturating_sub(5), -2); + assert_eq!(MIN.saturating_sub(1), MIN); + assert_eq!((-2isize).saturating_sub(MAX), MIN); + assert_eq!(3i32.saturating_sub(-5), 8); + assert_eq!(3isize.saturating_sub(-(MAX-1)), MAX); + assert_eq!(MAX.saturating_sub(-MAX), MAX); + assert_eq!((MAX-2).saturating_sub(-1), MAX-1); + } + + #[test] + fn test_checked_add() { + let five_less = usize::MAX - 5; + assert_eq!(five_less.checked_add(0), Some(usize::MAX - 5)); + assert_eq!(five_less.checked_add(1), Some(usize::MAX - 4)); + assert_eq!(five_less.checked_add(2), Some(usize::MAX - 3)); + assert_eq!(five_less.checked_add(3), Some(usize::MAX - 2)); + assert_eq!(five_less.checked_add(4), Some(usize::MAX - 1)); + assert_eq!(five_less.checked_add(5), Some(usize::MAX)); + assert_eq!(five_less.checked_add(6), None); + assert_eq!(five_less.checked_add(7), None); + } + + #[test] + fn test_checked_sub() { + assert_eq!(5_usize.checked_sub(0), Some(5)); + assert_eq!(5_usize.checked_sub(1), Some(4)); + assert_eq!(5_usize.checked_sub(2), Some(3)); + assert_eq!(5_usize.checked_sub(3), Some(2)); + assert_eq!(5_usize.checked_sub(4), Some(1)); + assert_eq!(5_usize.checked_sub(5), Some(0)); + assert_eq!(5_usize.checked_sub(6), None); + assert_eq!(5_usize.checked_sub(7), None); + } + + #[test] + fn test_checked_mul() { + let third = usize::MAX / 3; + assert_eq!(third.checked_mul(0), Some(0)); + assert_eq!(third.checked_mul(1), Some(third)); + assert_eq!(third.checked_mul(2), Some(third * 2)); + assert_eq!(third.checked_mul(3), Some(third * 3)); + assert_eq!(third.checked_mul(4), None); + } + + macro_rules! test_is_power_of_two { + ($test_name:ident, $T:ident) => ( + fn $test_name() { + #![test] + assert_eq!((0 as $T).is_power_of_two(), false); + assert_eq!((1 as $T).is_power_of_two(), true); + assert_eq!((2 as $T).is_power_of_two(), true); + assert_eq!((3 as $T).is_power_of_two(), false); + assert_eq!((4 as $T).is_power_of_two(), true); + assert_eq!((5 as $T).is_power_of_two(), false); + assert_eq!(($T::MAX / 2 + 1).is_power_of_two(), true); + } + ) + } + + test_is_power_of_two!{ test_is_power_of_two_u8, u8 } + test_is_power_of_two!{ test_is_power_of_two_u16, u16 } + test_is_power_of_two!{ test_is_power_of_two_u32, u32 } + test_is_power_of_two!{ test_is_power_of_two_u64, u64 } + test_is_power_of_two!{ test_is_power_of_two_uint, usize } + + macro_rules! test_next_power_of_two { + ($test_name:ident, $T:ident) => ( + fn $test_name() { + #![test] + assert_eq!((0 as $T).next_power_of_two(), 1); + let mut next_power = 1; + for i in 1 as $T..40 { + assert_eq!(i.next_power_of_two(), next_power); + if i == next_power { next_power *= 2 } + } + } + ) + } + + test_next_power_of_two! { test_next_power_of_two_u8, u8 } + test_next_power_of_two! { test_next_power_of_two_u16, u16 } + test_next_power_of_two! { test_next_power_of_two_u32, u32 } + test_next_power_of_two! { test_next_power_of_two_u64, u64 } + test_next_power_of_two! { test_next_power_of_two_uint, usize } + + macro_rules! test_checked_next_power_of_two { + ($test_name:ident, $T:ident) => ( + fn $test_name() { + #![test] + assert_eq!((0 as $T).checked_next_power_of_two(), Some(1)); + assert!(($T::MAX / 2).checked_next_power_of_two().is_some()); + assert_eq!(($T::MAX - 1).checked_next_power_of_two(), None); + assert_eq!($T::MAX.checked_next_power_of_two(), None); + let mut next_power = 1; + for i in 1 as $T..40 { + assert_eq!(i.checked_next_power_of_two(), Some(next_power)); + if i == next_power { next_power *= 2 } + } + } + ) + } + + test_checked_next_power_of_two! { test_checked_next_power_of_two_u8, u8 } + test_checked_next_power_of_two! { test_checked_next_power_of_two_u16, u16 } + test_checked_next_power_of_two! { test_checked_next_power_of_two_u32, u32 } + test_checked_next_power_of_two! { test_checked_next_power_of_two_u64, u64 } + test_checked_next_power_of_two! { test_checked_next_power_of_two_uint, usize } + + #[test] + fn test_pow() { + fn naive_pow<T: Mul<Output=T> + Copy>(one: T, base: T, exp: usize) -> T { + (0..exp).fold(one, |acc, _| acc * base) + } + macro_rules! assert_pow { + (($num:expr, $exp:expr) => $expected:expr) => {{ + let result = $num.pow($exp); + assert_eq!(result, $expected); + assert_eq!(result, naive_pow(1, $num, $exp)); + }} + } + assert_pow!((3u32, 0 ) => 1); + assert_pow!((5u32, 1 ) => 5); + assert_pow!((-4i32, 2 ) => 16); + assert_pow!((8u32, 3 ) => 512); + assert_pow!((2u64, 50) => 1125899906842624); + } + + #[test] + fn test_uint_to_str_overflow() { + let mut u8_val: u8 = 255; + assert_eq!(u8_val.to_string(), "255"); + + u8_val = u8_val.wrapping_add(1); + assert_eq!(u8_val.to_string(), "0"); + + let mut u16_val: u16 = 65_535; + assert_eq!(u16_val.to_string(), "65535"); + + u16_val = u16_val.wrapping_add(1); + assert_eq!(u16_val.to_string(), "0"); + + let mut u32_val: u32 = 4_294_967_295; + assert_eq!(u32_val.to_string(), "4294967295"); + + u32_val = u32_val.wrapping_add(1); + assert_eq!(u32_val.to_string(), "0"); + + let mut u64_val: u64 = 18_446_744_073_709_551_615; + assert_eq!(u64_val.to_string(), "18446744073709551615"); + + u64_val = u64_val.wrapping_add(1); + assert_eq!(u64_val.to_string(), "0"); + } + + fn from_str<T: ::str::FromStr>(t: &str) -> Option<T> { + ::str::FromStr::from_str(t).ok() + } + + #[test] + fn test_uint_from_str_overflow() { + let mut u8_val: u8 = 255; + assert_eq!(from_str::<u8>("255"), Some(u8_val)); + assert_eq!(from_str::<u8>("256"), None); + + u8_val = u8_val.wrapping_add(1); + assert_eq!(from_str::<u8>("0"), Some(u8_val)); + assert_eq!(from_str::<u8>("-1"), None); + + let mut u16_val: u16 = 65_535; + assert_eq!(from_str::<u16>("65535"), Some(u16_val)); + assert_eq!(from_str::<u16>("65536"), None); + + u16_val = u16_val.wrapping_add(1); + assert_eq!(from_str::<u16>("0"), Some(u16_val)); + assert_eq!(from_str::<u16>("-1"), None); + + let mut u32_val: u32 = 4_294_967_295; + assert_eq!(from_str::<u32>("4294967295"), Some(u32_val)); + assert_eq!(from_str::<u32>("4294967296"), None); + + u32_val = u32_val.wrapping_add(1); + assert_eq!(from_str::<u32>("0"), Some(u32_val)); + assert_eq!(from_str::<u32>("-1"), None); + + let mut u64_val: u64 = 18_446_744_073_709_551_615; + assert_eq!(from_str::<u64>("18446744073709551615"), Some(u64_val)); + assert_eq!(from_str::<u64>("18446744073709551616"), None); + + u64_val = u64_val.wrapping_add(1); + assert_eq!(from_str::<u64>("0"), Some(u64_val)); + assert_eq!(from_str::<u64>("-1"), None); + } +} + + +#[cfg(test)] +mod bench { + extern crate test; + use self::test::Bencher; + + #[bench] + fn bench_pow_function(b: &mut Bencher) { + let v = (0..1024).collect::<Vec<u32>>(); + b.iter(|| {v.iter().fold(0u32, |old, new| old.pow(*new as u32));}); + } +} |