schubfach

Schubfach algorithm

This is a Rust implementation of the Schufbach algorithm that converts IEEE-754 double-precision floating-point values to their string decimal representation.

It is performant and has a relatively small footprint. For performance comparisons, check the Drachennest project or the Dragonbox project.

Status

WARNING! This is very much work-in-progress.

The code is functional but must still be more thoroughly tested and optimized. The API is not considered as definitive yet, not is the code architecture.

Current features:

double-precision values (f64) are supported
a simple function converts values to a simple string format, either fixed or scientific depending on the value
a more complex function offers more choices, like
- fixed / scientific format selection
- precision
- correct rounding to even
- interface through method or Display trait

Planned features:

engineering format

References

The algorithm is described by its author in the following article:

Raffaello Giulietti, "The Schubfach way to render doubles", March 16, 2020,

The author made a Java implementation:

https://github.com/c4f7fcce9cb06515/Schubfach

The Rust code is mainly a translation from Alexander Bolz's C++ implementation:

https://github.com/abolz/Drachennest

with the following licence:

Copyright 2020 Alexander Bolz

Distributed under the Boost Software License, Version 1.0.
 (See accompanying file LICENSE_1_0.txt or copy at 
  https://www.boost.org/LICENSE_1_0.txt)

Compatibility

The schubfach crate is tested for rustc 1.68 and greater, on Windows 64-bit and Linux 64/32-bit platforms. There shouldn't be any problem with older versions.

License