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, Eq};
use ops::{Add, Div, Modulo, Mul, Neg, Sub};
use option::{None, Option, Some};
use kinds::Copy;
pub mod strconv;
pub trait IntConvertible {
pure fn to_int(&self) -> int;
static pure fn from_int(n: int) -> Self;
}
pub trait Zero {
static pure fn zero() -> Self;
}
pub trait One {
static pure fn one() -> Self;
}
pub pure fn abs<T:Ord + Zero + Neg<T>>(v: T) -> T {
if v < Zero::zero() { v.neg() } else { v }
}
pub trait Round {
pure fn round(&self, mode: RoundMode) -> Self;
pure fn floor(&self) -> Self;
pure fn ceil(&self) -> Self;
pure 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);
* fail_unless!(twenty == 20f32);
* ~~~
*/
#[inline(always)]
pub pure fn cast<T:NumCast,U:NumCast>(n: T) -> U {
NumCast::from(n)
}
/**
* An interface for generic numeric type casts
*/
pub trait NumCast {
static pure fn from<T:NumCast>(n: T) -> Self;
pure fn to_u8(&self) -> u8;
pure fn to_u16(&self) -> u16;
pure fn to_u32(&self) -> u32;
pure fn to_u64(&self) -> u64;
pure fn to_uint(&self) -> uint;
pure fn to_i8(&self) -> i8;
pure fn to_i16(&self) -> i16;
pure fn to_i32(&self) -> i32;
pure fn to_i64(&self) -> i64;
pure fn to_int(&self) -> int;
pure fn to_f32(&self) -> f32;
pure fn to_f64(&self) -> f64;
pure fn to_float(&self) -> float;
}
pub trait ToStrRadix {
pub pure fn to_str_radix(&self, radix: uint) -> ~str;
}
pub trait FromStrRadix {
static pub pure 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 pure 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
}
|
