comm-central/third_party/rust/ryu/src/lib.rs

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//! [![github]](https://github.com/dtolnay/ryu) [![crates-io]](https://crates.io/crates/ryu) [![docs-rs]](https://docs.rs/ryu)
//!
//!
//! <br>
//!
//! Pure Rust implementation of Ryū, an algorithm to quickly convert floating
//! point numbers to decimal strings.
//!
//! The PLDI'18 paper [*Ryū: fast float-to-string conversion*][paper] by Ulf
//! Adams includes a complete correctness proof of the algorithm. The paper is
//! available under the creative commons CC-BY-SA license.
//!
//! This Rust implementation is a line-by-line port of Ulf Adams' implementation
//! in C, [https://github.com/ulfjack/ryu][upstream].
//!
//!
//! # Example
//!
//! ```
//! fn main() {
//! let mut buffer = ryu::Buffer::new();
//! let printed = buffer.format(1.234);
//! assert_eq!(printed, "1.234");
//! }
//! ```
//!
//! ## Performance (lower is better)
//!
//!
//! You can run upstream's benchmarks with:
//!
//! ```console
//! $ git clone https://github.com/ulfjack/ryu c-ryu
//! $ cd c-ryu
//! $ bazel run -c opt //ryu/benchmark
//! ```
//!
//! And the same benchmark against our implementation with:
//!
//! ```console
//! $ git clone https://github.com/dtolnay/ryu rust-ryu
//! $ cd rust-ryu
//! $ cargo run --example upstream_benchmark --release
//! ```
//!
//! These benchmarks measure the average time to print a 32-bit float and average
//! time to print a 64-bit float, where the inputs are distributed as uniform random
//! bit patterns 32 and 64 bits wide.
//!
//! The upstream C code, the unsafe direct Rust port, and the safe pretty Rust API
//! all perform the same, taking around 21 nanoseconds to format a 32-bit float and
//! 31 nanoseconds to format a 64-bit float.
//!
//! There is also a Rust-specific benchmark comparing this implementation to the
//! standard library which you can run with:
//!
//! ```console
//! $ cargo bench
//! ```
//!
//! The benchmark shows Ryū approximately 2-5x faster than the standard library
//! across a range of f32 and f64 inputs. Measurements are in nanoseconds per
//! iteration; smaller is better.
//!
//! ## Formatting
//!
//! This library tends to produce more human-readable output than the standard
//! library's to\_string, which never uses scientific notation. Here are two
//! examples:
//!
//! - *ryu:* 1.23e40, *std:* 12300000000000000000000000000000000000000
//! - *ryu:* 1.23e-40, *std:* 0.000000000000000000000000000000000000000123
//!
//! Both libraries print short decimals such as 0.0000123 without scientific
//! notation.
#![no_std]
#![doc(html_root_url = "https://docs.rs/ryu/1.0.12")]
#![allow(
clippy::cast_lossless,
clippy::cast_possible_truncation,
clippy::cast_possible_wrap,
clippy::cast_sign_loss,
clippy::checked_conversions,
clippy::doc_markdown,
clippy::expl_impl_clone_on_copy,
clippy::if_not_else,
clippy::many_single_char_names,
clippy::missing_panics_doc,
clippy::module_name_repetitions,
clippy::must_use_candidate,
clippy::similar_names,
clippy::too_many_lines,
clippy::unreadable_literal,
clippy::unseparated_literal_suffix,
clippy::wildcard_imports
)]
mod buffer;
mod common;
mod d2s;
#[cfg(not(feature = "small"))]
mod d2s_full_table;
mod d2s_intrinsics;
#[cfg(feature = "small")]
mod d2s_small_table;
mod digit_table;
mod f2s;
mod f2s_intrinsics;
mod pretty;
pub use crate::buffer::{Buffer, Float};
/// Unsafe functions that mirror the API of the C implementation of Ryū.
pub mod raw {
pub use crate::pretty::{format32, format64};
}