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reifydb_value/value/
ordered_f32.rs

1// SPDX-License-Identifier: MIT
2// Copyright (c) 2026 ReifyDB
3
4use std::{
5	cmp::Ordering,
6	fmt,
7	fmt::{Display, Formatter},
8	hash::{Hash, Hasher},
9	ops::Deref,
10};
11
12use serde::{Deserialize, Deserializer, Serialize, Serializer, de, de::Visitor};
13
14use crate::{
15	error::{Error, TypeError},
16	util::float_format::format_f32,
17};
18
19#[repr(transparent)]
20#[derive(Debug, Copy, Clone, Default)]
21pub struct OrderedF32(f32);
22
23impl Serialize for OrderedF32 {
24	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
25	where
26		S: Serializer,
27	{
28		serializer.serialize_f32(self.0)
29	}
30}
31
32impl<'de> Deserialize<'de> for OrderedF32 {
33	fn deserialize<D>(deserializer: D) -> Result<OrderedF32, D::Error>
34	where
35		D: Deserializer<'de>,
36	{
37		struct F32Visitor;
38
39		impl Visitor<'_> for F32Visitor {
40			type Value = OrderedF32;
41
42			fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
43				formatter.write_str("a 32-bit floating point number")
44			}
45
46			fn visit_f32<E>(self, value: f32) -> Result<Self::Value, E> {
47				Ok(OrderedF32(value))
48			}
49
50			fn visit_f64<E>(self, value: f64) -> Result<Self::Value, E>
51			where
52				E: de::Error,
53			{
54				Ok(OrderedF32(value as f32))
55			}
56		}
57
58		deserializer.deserialize_f32(F32Visitor)
59	}
60}
61
62impl OrderedF32 {
63	pub fn value(&self) -> f32 {
64		self.0
65	}
66
67	pub fn zero() -> OrderedF32 {
68		OrderedF32(0.0f32)
69	}
70}
71
72impl Deref for OrderedF32 {
73	type Target = f32;
74
75	fn deref(&self) -> &Self::Target {
76		&self.0
77	}
78}
79
80impl Display for OrderedF32 {
81	fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
82		f.write_str(&format_f32(self.0))
83	}
84}
85
86impl PartialEq for OrderedF32 {
87	fn eq(&self, other: &Self) -> bool {
88		self.0.to_bits() == other.0.to_bits()
89	}
90}
91
92impl Eq for OrderedF32 {}
93
94impl PartialOrd for OrderedF32 {
95	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
96		Some(self.cmp(other))
97	}
98}
99
100impl Ord for OrderedF32 {
101	fn cmp(&self, other: &Self) -> Ordering {
102		let l = float_to_ordered_u32(self.0);
103		let r = float_to_ordered_u32(other.0);
104		l.cmp(&r)
105	}
106}
107
108#[inline]
109fn float_to_ordered_u32(f: f32) -> u32 {
110	let bits = f.to_bits();
111	if bits & 0x80000000 == 0 {
112		bits ^ 0x80000000
113	} else {
114		!bits
115	}
116}
117
118impl Hash for OrderedF32 {
119	fn hash<H: Hasher>(&self, state: &mut H) {
120		self.0.to_bits().hash(state);
121	}
122}
123
124impl From<OrderedF32> for f32 {
125	fn from(v: OrderedF32) -> Self {
126		v.0
127	}
128}
129
130impl TryFrom<f32> for OrderedF32 {
131	type Error = Error;
132
133	fn try_from(f: f32) -> Result<Self, Self::Error> {
134		let normalized = if f == 0.0 {
135			0.0
136		} else {
137			f
138		};
139		if f.is_nan() {
140			Err(TypeError::NanNotAllowed.into())
141		} else {
142			Ok(OrderedF32(normalized))
143		}
144	}
145}
146
147#[cfg(test)]
148pub mod tests {
149	use std::{collections::HashSet, convert::TryFrom};
150
151	use super::*;
152
153	#[test]
154	fn test_sorting() {
155		let mut values = vec![
156			OrderedF32::try_from(10.0).unwrap(),
157			OrderedF32::try_from(2.0).unwrap(),
158			OrderedF32::try_from(5.0).unwrap(),
159		];
160		values.sort();
161		let sorted: Vec<f32> = values.into_iter().map(|v| v.0).collect();
162		assert_eq!(sorted, vec![2.0, 5.0, 10.0]);
163	}
164
165	#[test]
166	fn test_hash_eq() {
167		let a = OrderedF32::try_from(1.0).unwrap();
168		let b = OrderedF32::try_from(1.0).unwrap();
169
170		let mut set = HashSet::new();
171		set.insert(a);
172		assert!(set.contains(&b));
173	}
174
175	#[test]
176	fn test_normalizes_zero() {
177		let pos_zero = OrderedF32::try_from(0.0).unwrap();
178		let neg_zero = OrderedF32::try_from(-0.0).unwrap();
179
180		assert_eq!(pos_zero, neg_zero);
181
182		let mut set = HashSet::new();
183		set.insert(pos_zero);
184		assert!(set.contains(&neg_zero));
185	}
186
187	#[test]
188	fn test_nan_fails() {
189		assert!(OrderedF32::try_from(f32::NAN).is_err());
190	}
191
192	#[test]
193	fn test_negative_less_than_positive() {
194		let neg = OrderedF32::try_from(-1.5).unwrap();
195		let pos = OrderedF32::try_from(1.5).unwrap();
196		assert!(neg < pos);
197	}
198
199	#[test]
200	fn test_negative_less_than_zero() {
201		let neg = OrderedF32::try_from(-0.0001).unwrap();
202		let zero = OrderedF32::try_from(0.0).unwrap();
203		assert!(neg < zero);
204	}
205
206	#[test]
207	fn test_sorting_with_negatives() {
208		let mut values = vec![
209			OrderedF32::try_from(3.14).unwrap(),
210			OrderedF32::try_from(-1.5).unwrap(),
211			OrderedF32::try_from(0.0).unwrap(),
212			OrderedF32::try_from(99999.0).unwrap(),
213			OrderedF32::try_from(-100.0).unwrap(),
214		];
215		values.sort();
216		let sorted: Vec<f32> = values.into_iter().map(|v| v.0).collect();
217		assert_eq!(sorted, vec![-100.0, -1.5, 0.0, 3.14, 99999.0]);
218	}
219}