1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
// 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.
//! An interface for numeric types
use cmp::Ord;
use ops::{Div, Mul, Neg};
use option::Option;
use kinds::Copy;
pub mod strconv;
pub trait IntConvertible {
fn to_int(&self) -> int;
fn from_int(n: int) -> Self;
}
pub trait Zero {
fn zero() -> Self;
}
pub trait One {
fn one() -> Self;
}
pub fn abs<T:Ord + Zero + Neg<T>>(v: T) -> T {
if v < Zero::zero() { v.neg() } else { v }
}
pub trait Round {
fn round(&self, mode: RoundMode) -> Self;
fn floor(&self) -> Self;
fn ceil(&self) -> Self;
fn fract(&self) -> Self;
}
pub enum RoundMode {
RoundDown,
RoundUp,
RoundToZero,
RoundFromZero
}
/**
* Cast a number the the enclosing type
*
* # Example
*
* ~~~
* let twenty: f32 = num::cast(0x14);
* assert!(twenty == 20f32);
* ~~~
*/
#[inline(always)]
pub fn cast<T:NumCast,U:NumCast>(n: T) -> U {
NumCast::from(n)
}
/**
* An interface for generic numeric type casts
*/
pub trait NumCast {
fn from<T:NumCast>(n: T) -> Self;
fn to_u8(&self) -> u8;
fn to_u16(&self) -> u16;
fn to_u32(&self) -> u32;
fn to_u64(&self) -> u64;
fn to_uint(&self) -> uint;
fn to_i8(&self) -> i8;
fn to_i16(&self) -> i16;
fn to_i32(&self) -> i32;
fn to_i64(&self) -> i64;
fn to_int(&self) -> int;
fn to_f32(&self) -> f32;
fn to_f64(&self) -> f64;
fn to_float(&self) -> float;
}
pub trait ToStrRadix {
pub fn to_str_radix(&self, radix: uint) -> ~str;
}
pub trait FromStrRadix {
pub fn from_str_radix(str: &str, radix: uint) -> Option<Self>;
}
// Generic math functions:
/**
* Calculates a power to a given radix, optimized for uint `pow` and `radix`.
*
* Returns `radix^pow` as `T`.
*
* Note:
* Also returns `1` for `0^0`, despite that technically being an
* undefined number. The reason for this is twofold:
* - If code written to use this function cares about that special case, it's
* probably going to catch it before making the call.
* - If code written to use this function doesn't care about it, it's
* probably assuming that `x^0` always equals `1`.
*/
pub fn pow_with_uint<T:NumCast+One+Zero+Copy+Div<T,T>+Mul<T,T>>(
radix: uint, pow: uint) -> T {
let _0: T = Zero::zero();
let _1: T = One::one();
if pow == 0u { return _1; }
if radix == 0u { return _0; }
let mut my_pow = pow;
let mut total = _1;
let mut multiplier = cast(radix as int);
while (my_pow > 0u) {
if my_pow % 2u == 1u {
total *= multiplier;
}
my_pow /= 2u;
multiplier *= multiplier;
}
total
}
|
