humenda/isolang-rs

Rust library to convert between ISO 639 codes and English language names

Rust

40

137 commits

updated Feb 15, 2026

See the code

README

ISO 639 language codes

Build Status Crates.io Documentation Licence: Apache 2.0

Introduction

When dealing with different language inputs and APIs, different standards are used to identify a language. Converting between these in an automated way can be tedious. This crate provides an enum which enables conversion between the standards 639-1, 639-2t, 639-2b and 639-3, as well as conversion into English and local names (autonyms).

This crate contains the ISO 639 table in statically embedded tables. This increases binary size, but allows for very efficient look-up if performance matters. If size is a concern, both and the English names and local names can be enabled or disabled individually.

This crate is licensed under the Apache 2.0 license, please see LICENSE.md for the details.

Usage

Cargo.toml:

[dependencies]
isolang = "2.0"

Example

use isolang::Language;

assert_eq!(Language::from_639_1("de").unwrap().to_name(), "German");
assert_eq!(Language::from_639_2b("fre").unwrap().to_name(), "French");
assert_eq!(Language::from_639_2t("fra").unwrap().to_name(), "French");
assert_eq!(Language::from_639_3("spa").unwrap().to_639_1(), Some("es"));
// undefined language (ISO code und)
assert_eq!(Language::default(), Language::Und);
use isolang::Language;
// `to_name()` is available if compiled with the `english_names` feature.
assert_eq!(Language::from_str("es").unwrap().to_name(), "Spanish");
assert_eq!(Language::from_str("spa").unwrap().to_name(), "Spanish");
// `from_str(lowercase_name)` is available if compiled with the `english_names` and `lowercase_names` features.
assert_eq!(Language::from_str("spanish").unwrap().to_name(), "Spanish");
// `from_str(local_name)` is available if compiled with the `english_names`, `lowercase_names` and `local_names` features.
assert_eq!(Language::from_str("español").unwrap().to_name(), "Spanish");

Supported Cargo Features

Please take a look at the commented Cargo.toml file for a up-to-date list of supported features.

Serde support

This crate also supports serializing the Language enum. To enable this please add the following lines to your Cargo.toml (instead of the above code):

[dependencies.isolang]
features = ["serde"]
version = "2.0"

Data Source

The data is downloaded from https://iso639-3.sil.org/code_tables/download_tables.

humenda/isolang-rs

Rust library to convert between ISO 639 codes and English language names

Rust

40

137 commits

updated Feb 15, 2026

See the code

README

ISO 639 language codes

Build Status Crates.io Documentation Licence: Apache 2.0

Introduction

When dealing with different language inputs and APIs, different standards are used to identify a language. Converting between these in an automated way can be tedious. This crate provides an enum which enables conversion between the standards 639-1, 639-2t, 639-2b and 639-3, as well as conversion into English and local names (autonyms).

This crate contains the ISO 639 table in statically embedded tables. This increases binary size, but allows for very efficient look-up if performance matters. If size is a concern, both and the English names and local names can be enabled or disabled individually.

This crate is licensed under the Apache 2.0 license, please see LICENSE.md for the details.

Usage

Cargo.toml:

[dependencies]
isolang = "2.0"

Example

use isolang::Language;

assert_eq!(Language::from_639_1("de").unwrap().to_name(), "German");
assert_eq!(Language::from_639_2b("fre").unwrap().to_name(), "French");
assert_eq!(Language::from_639_2t("fra").unwrap().to_name(), "French");
assert_eq!(Language::from_639_3("spa").unwrap().to_639_1(), Some("es"));
// undefined language (ISO code und)
assert_eq!(Language::default(), Language::Und);
use isolang::Language;
// `to_name()` is available if compiled with the `english_names` feature.
assert_eq!(Language::from_str("es").unwrap().to_name(), "Spanish");
assert_eq!(Language::from_str("spa").unwrap().to_name(), "Spanish");
// `from_str(lowercase_name)` is available if compiled with the `english_names` and `lowercase_names` features.
assert_eq!(Language::from_str("spanish").unwrap().to_name(), "Spanish");
// `from_str(local_name)` is available if compiled with the `english_names`, `lowercase_names` and `local_names` features.
assert_eq!(Language::from_str("español").unwrap().to_name(), "Spanish");

Supported Cargo Features

Please take a look at the commented Cargo.toml file for a up-to-date list of supported features.

Serde support

This crate also supports serializing the Language enum. To enable this please add the following lines to your Cargo.toml (instead of the above code):

[dependencies.isolang]
features = ["serde"]
version = "2.0"

Data Source

The data is downloaded from https://iso639-3.sil.org/code_tables/download_tables.

Project health

Overall

3.0/10

Maintained

0/10

Code review

3/10
OpenSSF Scorecard

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