Tejú Jaguá

Tejú Jaguá is an algorithm for converting floating point values into strings. This crate is an implementation of this algorithm in Rust.

teju is an alternative to the formatting facilities in Rust's std library. It is also a drop-in replacement for ryu, another very popular crate to format floating point values (this crate implements the same interface).

Compared to ryu, it should have the following advantages:

• It's faster.

• Can format in decimal and scientific notation.

Usage

teju is very simple to use. teju::Buffer provides enough storage for the string, and the format function writes the string to that storage and returns it as a &str.

assert_eq!(teju::Buffer::new().format(1.234), "1.234")

Storage is stack allocated so you don't need to worry about re-using Buffers for efficiency. To force scientific notation or decimal notation, use format_exp/format_dec, respectively.

Performance

Tejú Jaguá is a very fast algorithm. As a ballpark estimate, this crate should be around 1.5–6× faster than ryu and 3–8× faster than std/core.

These are microbenchmarks so take them with a grain of salt. A few more comprehensive benchmarks are included; run them with cargo bench.

Implementation

The core Tejú algorithm and C implementation are all by Cassio Neri; for more info refer to https://github.com/cassioneri/teju_jagua. The algorithms for rendering to string are based on a two-digit lookup table.

This crate has no (non-dev) dependencies, and can be used in no_std contexts.