• Home
Name Date Size #Lines LOC

..--

.github/workflows/03-May-2024-6457

benches/03-May-2024-5848

examples/03-May-2024-8672

src/03-May-2024-2,7662,055

tests/03-May-2024-1,005719

.cargo_vcs_info.jsonD03-May-202494 66

.clippy.tomlD03-May-202416 21

.gitignoreD03-May-202440 54

Android.bpD03-May-20243.3 KiB131120

Cargo.tomlD03-May-20241.1 KiB4136

Cargo.toml.origD03-May-2024940 3227

LICENSED03-May-202411.9 KiB228190

LICENSE-APACHED03-May-202411.1 KiB202169

LICENSE-BOOSTD03-May-20241.3 KiB2420

METADATAD03-May-2024359 2019

MODULE_LICENSE_APACHE2D03-May-20240

OWNERSD03-May-202440 21

README.mdD03-May-20244.6 KiB11179

TEST_MAPPINGD03-May-20241.7 KiB9493

cargo2android.jsonD03-May-2024159 1010

README.md

1# Ryū
2
3[<img alt="github" src="https://img.shields.io/badge/github-dtolnay/ryu-8da0cb?style=for-the-badge&labelColor=555555&logo=github" height="20">](https://github.com/dtolnay/ryu)
4[<img alt="crates.io" src="https://img.shields.io/crates/v/ryu.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/ryu)
5[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-ryu-66c2a5?style=for-the-badge&labelColor=555555&logoColor=white&logo=data:image/svg+xml;base64,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" height="20">](https://docs.rs/ryu)
6[<img alt="build status" src="https://img.shields.io/github/workflow/status/dtolnay/ryu/CI/master?style=for-the-badge" height="20">](https://github.com/dtolnay/ryu/actions?query=branch%3Amaster)
7
8Pure Rust implementation of Ryū, an algorithm to quickly convert floating point
9numbers to decimal strings.
10
11The PLDI'18 paper [*Ryū: fast float-to-string conversion*][paper] by Ulf Adams
12includes a complete correctness proof of the algorithm. The paper is available
13under the creative commons CC-BY-SA license.
14
15This Rust implementation is a line-by-line port of Ulf Adams' implementation in
16C, [https://github.com/ulfjack/ryu][upstream].
17
18*Requirements: this crate supports any compiler version back to rustc 1.36; it
19uses nothing from the Rust standard library so is usable from no_std crates.*
20
21[paper]: https://dl.acm.org/citation.cfm?id=3192369
22[upstream]: https://github.com/ulfjack/ryu/tree/abf76d252bc97300354857e64e80d4a2bf664291
23
24```toml
25[dependencies]
26ryu = "1.0"
27```
28
29<br>
30
31## Example
32
33```rust
34fn main() {
35    let mut buffer = ryu::Buffer::new();
36    let printed = buffer.format(1.234);
37    assert_eq!(printed, "1.234");
38}
39```
40
41<br>
42
43## Performance (lower is better)
44
45![performance](https://raw.githubusercontent.com/dtolnay/ryu/master/performance.png)
46
47You can run upstream's benchmarks with:
48
49```console
50$ git clone https://github.com/ulfjack/ryu c-ryu
51$ cd c-ryu
52$ bazel run -c opt //ryu/benchmark:ryu_benchmark
53```
54
55And the same benchmark against our implementation with:
56
57```console
58$ git clone https://github.com/dtolnay/ryu rust-ryu
59$ cd rust-ryu
60$ cargo run --example upstream_benchmark --release
61```
62
63These benchmarks measure the average time to print a 32-bit float and average
64time to print a 64-bit float, where the inputs are distributed as uniform random
65bit patterns 32 and 64 bits wide.
66
67The upstream C code, the unsafe direct Rust port, and the safe pretty Rust API
68all perform the same, taking around 21 nanoseconds to format a 32-bit float and
6931 nanoseconds to format a 64-bit float.
70
71There is also a Rust-specific benchmark comparing this implementation to the
72standard library which you can run with:
73
74```console
75$ cargo bench
76```
77
78The benchmark shows Ryū approximately 2-5x faster than the standard library
79across a range of f32 and f64 inputs. Measurements are in nanoseconds per
80iteration; smaller is better.
81
82## Formatting
83
84This library tends to produce more human-readable output than the standard
85library's to\_string, which never uses scientific notation. Here are two
86examples:
87
88- *ryu:* 1.23e40, *std:* 12300000000000000000000000000000000000000
89- *ryu:* 1.23e-40, *std:* 0.000000000000000000000000000000000000000123
90
91Both libraries print short decimals such as 0.0000123 without scientific
92notation.
93
94<br>
95
96#### License
97
98<sup>
99Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
1002.0</a> or <a href="LICENSE-BOOST">Boost Software License 1.0</a> at your
101option.
102</sup>
103
104<br>
105
106<sub>
107Unless you explicitly state otherwise, any contribution intentionally submitted
108for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
109be dual licensed as above, without any additional terms or conditions.
110</sub>
111