ordered-float 0.5.2

Wrappers for total ordering on floats.
Documentation 
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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276

#![feature(plugin)]
#![plugin(stainless)]

extern crate ordered_float;
extern crate num_traits;

pub use ordered_float::*;
pub use num_traits::Float;
pub use std::cmp::Ordering::*;
pub use std::{f32, f64, panic};

pub use std::collections::HashSet;
pub use std::collections::hash_map::RandomState;
pub use std::hash::*;

describe! ordered_float32 {
    it "should compare regular floats" {
        assert_eq!(OrderedFloat(7.0f32).cmp(&OrderedFloat(7.0)), Equal);
        assert_eq!(OrderedFloat(8.0f32).cmp(&OrderedFloat(7.0)), Greater);
        assert_eq!(OrderedFloat(4.0f32).cmp(&OrderedFloat(7.0)), Less);
    }

    it "should compare NaN" {
        let f32_nan: f32 = Float::nan();
        assert_eq!(OrderedFloat(f32_nan).cmp(&OrderedFloat(Float::nan())), Equal);
        assert_eq!(OrderedFloat(f32_nan).cmp(&OrderedFloat(-100000.0f32)), Greater);
        assert_eq!(OrderedFloat(-100.0f32).cmp(&OrderedFloat(Float::nan())), Less);
    }

    it "should compare regular floats with comparison operators" {
        assert!(OrderedFloat(7.0f32) == OrderedFloat(7.0));
        assert!(OrderedFloat(7.0f32) <= OrderedFloat(7.0));
        assert!(OrderedFloat(7.0f32) >= OrderedFloat(7.0));
        assert!(OrderedFloat(8.0f32) > OrderedFloat(7.0));
        assert!(OrderedFloat(8.0f32) >= OrderedFloat(7.0));
        assert!(OrderedFloat(4.0f32) < OrderedFloat(7.0));
        assert!(OrderedFloat(4.0f32) <= OrderedFloat(7.0));
    }

    it "should compare NaN with comparison operators" {
        let f32_nan: OrderedFloat<f32> = OrderedFloat(Float::nan());
        assert!(f32_nan == f32_nan);
        assert!(f32_nan <= f32_nan);
        assert!(f32_nan >= f32_nan);
        assert!(f32_nan > OrderedFloat(-100000.0f32));
        assert!(f32_nan >= OrderedFloat(-100000.0f32));
        assert!(OrderedFloat(-100.0f32) < f32_nan);
        assert!(OrderedFloat(-100.0f32) <= f32_nan);
        assert!(f32_nan > OrderedFloat(Float::infinity()));
        assert!(f32_nan >= OrderedFloat(Float::infinity()));
        assert!(f32_nan > OrderedFloat(Float::neg_infinity()));
        assert!(f32_nan >= OrderedFloat(Float::neg_infinity()));
    }
}

describe! ordered_float64 {
    it "should compare regular floats" {
        assert_eq!(OrderedFloat(7.0f64).cmp(&OrderedFloat(7.0)), Equal);
        assert_eq!(OrderedFloat(8.0f64).cmp(&OrderedFloat(7.0)), Greater);
        assert_eq!(OrderedFloat(4.0f64).cmp(&OrderedFloat(7.0)), Less);
    }

    it "should compare NaN" {
        let f64_nan: f64 = Float::nan();
        assert_eq!(OrderedFloat(f64_nan).cmp(&OrderedFloat(Float::nan())), Equal);
        assert_eq!(OrderedFloat(f64_nan).cmp(&OrderedFloat(-100000.0f64)), Greater);
        assert_eq!(OrderedFloat(-100.0f64).cmp(&OrderedFloat(Float::nan())), Less);
    }

    it "should compare regular floats with comparison operators" {
        assert!(OrderedFloat(7.0) == OrderedFloat(7.0));
        assert!(OrderedFloat(7.0) <= OrderedFloat(7.0));
        assert!(OrderedFloat(7.0) >= OrderedFloat(7.0));
        assert!(OrderedFloat(8.0) > OrderedFloat(7.0));
        assert!(OrderedFloat(8.0) >= OrderedFloat(7.0));
        assert!(OrderedFloat(4.0) < OrderedFloat(7.0));
        assert!(OrderedFloat(4.0) <= OrderedFloat(7.0));
    }

    it "should compare NaN with comparison operators" {
        let f64_nan: OrderedFloat<f64> = OrderedFloat(Float::nan());
        assert!(f64_nan == f64_nan);
        assert!(f64_nan <= f64_nan);
        assert!(f64_nan >= f64_nan);
        assert!(f64_nan > OrderedFloat(-100000.0));
        assert!(f64_nan >= OrderedFloat(-100000.0));
        assert!(OrderedFloat(-100.0) < f64_nan);
        assert!(OrderedFloat(-100.0) <= f64_nan);
        assert!(f64_nan > OrderedFloat(Float::infinity()));
        assert!(f64_nan >= OrderedFloat(Float::infinity()));
        assert!(f64_nan > OrderedFloat(Float::neg_infinity()));
        assert!(f64_nan >= OrderedFloat(Float::neg_infinity()));
    }
}

describe! not_nan32 {
    it "should compare regular floats" {
        assert_eq!(NotNaN::from(7.0f32).cmp(&NotNaN::from(7.0)), Equal);
        assert_eq!(NotNaN::from(8.0f32).cmp(&NotNaN::from(7.0)), Greater);
        assert_eq!(NotNaN::from(4.0f32).cmp(&NotNaN::from(7.0)), Less);
    }

    it "should fail when constructing NotNaN with NaN" {
        let f32_nan: f32 = Float::nan();
        assert!(NotNaN::new(f32_nan).is_err());
    }
    
    it "should calculate correctly" {
        assert_eq!(*(NotNaN::from(5.0f32) + NotNaN::from(4.0f32)), 5.0f32 + 4.0f32);
        assert_eq!(*(NotNaN::from(5.0f32) + 4.0f32), 5.0f32 + 4.0f32);
        assert_eq!(*(NotNaN::from(5.0f32) - NotNaN::from(4.0f32)), 5.0f32 - 4.0f32);
        assert_eq!(*(NotNaN::from(5.0f32) - 4.0f32), 5.0f32 - 4.0f32);
        assert_eq!(*(NotNaN::from(5.0f32) * NotNaN::from(4.0f32)), 5.0f32 * 4.0f32);
        assert_eq!(*(NotNaN::from(5.0f32) * 4.0f32), 5.0f32 * 4.0f32);
        assert_eq!(*(NotNaN::from(8.0f32) / NotNaN::from(4.0f32)), 8.0f32 / 4.0f32);
        assert_eq!(*(NotNaN::from(8.0f32) / 4.0f32), 8.0f32 / 4.0f32);
        assert_eq!(*(NotNaN::from(8.0f32) % NotNaN::from(4.0f32)), 8.0f32 % 4.0f32);
        assert_eq!(*(NotNaN::from(8.0f32) % 4.0f32), 8.0f32 % 4.0f32);
        assert_eq!(*(-NotNaN::from(1.0f32)), -1.0f32);
        
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f32) + f32::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f32) - f32::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f32) * f32::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f32) / f32::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f32) % f32::NAN}).is_err());
        
        let mut number = NotNaN::from(5.0f32);
        number += NotNaN::from(4.0f32);
        assert_eq!(*number, 9.0f32);
        number -= NotNaN::from(4.0f32);
        assert_eq!(*number, 5.0f32);
        number *= NotNaN::from(4.0f32);
        assert_eq!(*number, 20.0f32);
        number /= NotNaN::from(4.0f32);
        assert_eq!(*number, 5.0f32);
        number %= NotNaN::from(4.0f32);
        assert_eq!(*number, 1.0f32);
        
        number = NotNaN::from(5.0f32);
        number += 4.0f32;
        assert_eq!(*number, 9.0f32);
        number -= 4.0f32;
        assert_eq!(*number, 5.0f32);
        number *= 4.0f32;
        assert_eq!(*number, 20.0f32);
        number /= 4.0f32;
        assert_eq!(*number, 5.0f32);
        number %= 4.0f32;
        assert_eq!(*number, 1.0f32);
        
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f32); tmp += f32::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f32); tmp -= f32::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f32); tmp *= f32::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f32); tmp /= f32::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f32); tmp %= f32::NAN;}).is_err());
    }
}

describe! not_nan64 {
    it "should compare regular floats" {
        assert_eq!(NotNaN::from(7.0f64).cmp(&NotNaN::from(7.0)), Equal);
        assert_eq!(NotNaN::from(8.0f64).cmp(&NotNaN::from(7.0)), Greater);
        assert_eq!(NotNaN::from(4.0f64).cmp(&NotNaN::from(7.0)), Less);
    }

    it "should fail when constructing NotNaN with NaN" {
        let f64_nan: f64 = Float::nan();
        assert!(NotNaN::new(f64_nan).is_err());
    }
    
    it "should calculate correctly" {
        assert_eq!(*(NotNaN::from(5.0f64) + NotNaN::from(4.0f64)), 5.0f64 + 4.0f64);
        assert_eq!(*(NotNaN::from(5.0f64) + 4.0f64), 5.0f64 + 4.0f64);
        assert_eq!(*(NotNaN::from(5.0f64) - NotNaN::from(4.0f64)), 5.0f64 - 4.0f64);
        assert_eq!(*(NotNaN::from(5.0f64) - 4.0f64), 5.0f64 - 4.0f64);
        assert_eq!(*(NotNaN::from(5.0f64) * NotNaN::from(4.0f64)), 5.0f64 * 4.0f64);
        assert_eq!(*(NotNaN::from(5.0f64) * 4.0f64), 5.0f64 * 4.0f64);
        assert_eq!(*(NotNaN::from(8.0f64) / NotNaN::from(4.0f64)), 8.0f64 / 4.0f64);
        assert_eq!(*(NotNaN::from(8.0f64) / 4.0f64), 8.0f64 / 4.0f64);
        assert_eq!(*(NotNaN::from(8.0f64) % NotNaN::from(4.0f64)), 8.0f64 % 4.0f64);
        assert_eq!(*(NotNaN::from(8.0f64) % 4.0f64), 8.0f64 % 4.0f64);
        assert_eq!(*(-NotNaN::from(1.0f64)), -1.0f64);
        
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f64) + f64::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f64) - f64::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f64) * f64::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f64) / f64::NAN}).is_err());
        assert!(panic::catch_unwind(|| {NotNaN::from(0.0f64) % f64::NAN}).is_err());
        
        let mut number = NotNaN::from(5.0f64);
        number += NotNaN::from(4.0f64);
        assert_eq!(*number, 9.0f64);
        number -= NotNaN::from(4.0f64);
        assert_eq!(*number, 5.0f64);
        number *= NotNaN::from(4.0f64);
        assert_eq!(*number, 20.0f64);
        number /= NotNaN::from(4.0f64);
        assert_eq!(*number, 5.0f64);
        number %= NotNaN::from(4.0f64);
        assert_eq!(*number, 1.0f64);
        
        number = NotNaN::from(5.0f64);
        number += 4.0f64;
        assert_eq!(*number, 9.0f64);
        number -= 4.0f64;
        assert_eq!(*number, 5.0f64);
        number *= 4.0f64;
        assert_eq!(*number, 20.0f64);
        number /= 4.0f64;
        assert_eq!(*number, 5.0f64);
        number %= 4.0f64;
        assert_eq!(*number, 1.0f64);
        
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f64); tmp += f64::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f64); tmp -= f64::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f64); tmp *= f64::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f64); tmp /= f64::NAN;}).is_err());
        assert!(panic::catch_unwind(|| {let mut tmp = NotNaN::from(0.0f64); tmp %= f64::NAN;}).is_err());
    }
}

describe! hashing {
    it "should hash zero and neg-zero to the same hc" {
        let state = RandomState::new();
        let mut h1 = state.build_hasher();
        let mut h2 = state.build_hasher();
        OrderedFloat::from(0f64).hash(&mut h1);
        OrderedFloat::from(-0f64).hash(&mut h2);
        assert_eq!(h1.finish(), h2.finish());
    }

    it "should hash inf and neg-inf to different hcs" {
        let state = RandomState::new();
        let mut h1 = state.build_hasher();
        let mut h2 = state.build_hasher();
        OrderedFloat::from(f64::INFINITY).hash(&mut h1);
        OrderedFloat::from(f64::NEG_INFINITY).hash(&mut h2);
        assert!(h1.finish() != h2.finish());
    }

    it "should have a good hash function for whole numbers" {
        let state = RandomState::new();
        let limit = 10000;

        let mut set = ::std::collections::HashSet::with_capacity(limit);
        for i in 0..limit {
            let mut h = state.build_hasher();
            OrderedFloat::from(i as f64).hash(&mut h);
            set.insert(h.finish());
        }

        // This allows 100 collisions, which is far too
        // many, but should guard against transient issues
        // that will result from using RandomState
        let pct_unique = set.len() as f64 / limit as f64;
        assert!(0.99f64 < pct_unique, "percent-unique={}", pct_unique);
    }

    it "should have a good hash function for fractional numbers" {
        let state = RandomState::new();
        let limit = 10000;

        let mut set = ::std::collections::HashSet::with_capacity(limit);
        for i in 0..limit {
            let mut h = state.build_hasher();
            OrderedFloat::from(i as f64 * (1f64 / limit as f64)).hash(&mut h);
            set.insert(h.finish());
        }

        // This allows 100 collisions, which is far too
        // many, but should guard against transient issues
        // that will result from using RandomState
        let pct_unique = set.len() as f64 / limit as f64;
        assert!(0.99f64 < pct_unique, "percent-unique={}", pct_unique);
    }
}