thousands 0.2.0

Adds digit separators to numbers, configurably.


Build Status License: MIT License: Apache 2.0

Provides a trait, Separable, for formatting numbers with separators between the digits. Typically this will be used to add commas or spaces every three digits from the right, but can be configured via a SeparatorPolicy.


The simplest way to use the library is with trait Separable’s method separate_with_commas method, which does what it sounds like:

use thousands::Separable;

 assert_eq!(   12345  .separate_with_commas(),  "12,345" );
 assert_eq!( (-12345) .separate_with_commas(), "-12,345" );
 assert_eq!(    9876.5.separate_with_commas(),   "9,876.5" );

There are also methods separate_with_spaces, separate_with_dots, and separate_with_underscores, in case you, your culture, or your file format prefer those separators.

However, it's also possible to pass a policy for different behavior:

use thousands::{Separable, SeparatorPolicy, digits};

let policy = SeparatorPolicy {
    separator: ',',
    groups:    &[3, 2],
    digits:    digits::ASCII_DECIMAL,

assert_eq!( 1234567890.separate_by_policy(policy), "1,23,45,67,890" );


It’s on, so you can add

thousands = "0.2.0"

to your Cargo.toml.

This crate supports Rust version 1.22 and newer.