sealed_languages 0.2.0

Provides data for world languages in the form of sealed classes.

This ISO-driven, pure Dart, fully tested and and dependency-free package provides information about world languages in form of compile-time constant sealed classes. Contains the all 184 languages with ISO 639-1 codes, also provides ISO 639-2 codes, their English, native names, language family info, etc. For Flutter ready widgets (like language picker) please use world_countries package.

Features

NaturalLanguage class provides the following information about languages:

Field	Mandatory	Description	Example for LangEng
name	Yes	A non-empty string representing the English name of the natural language.	"English"
code	Yes	A three-letter string representing the ISO 639-2/T Terminological code for the language.	"ENG"
codeShort	Yes	A two-letter string representing the ISO 639-1 code for the language.	"EN"
namesNative	Yes	A list of non-empty strings representing the language's native names.	["English"]
bibliographicCode	No	A three-letter string representing the ISO 639-2/B Bibliographic code for the language.	null
family	No	The language family to which the language belongs.	LanguageFamily(name: "Indo-European")
isRightToLeft	No	A boolean value specifying whether the language is written right-to-left.	false

Compile time constant list of all languages accessible via NaturalLanguage.list and more over, the NaturalLanguage class provides the following methods:

• maybeFromValue - returns a language instance if the value matches the provided value, otherwise returns null.
• fromCode - returns a language instance if the value matches the provided ISO 639-2 code.
• fromCodeShort - returns a language instance if the value matches the provided ISO 639-1 code code.
• fromName - returns a language instance if the value matches the provided name.

and (thanks to sealed nature of the class) functional-style like methods: whenOrNull, maybeWhen, when, map, maybeMap.

Getting started

To use this package, add sealed_languages as a dependency in your pubspec.yaml file.

dependencies:
  sealed_languages: any

Then import the package in your Dart code:

import 'package:sealed_languages/sealed_languages.dart';

Usage

Use NaturalLanguage class to get information about languages. Either construct a new instance directly or with use of the class factory constructors/method fromCode, fromCodeShort, fromName or from any value that class contains maybeFromValue, or select one from the NaturalLanguage.list constant.

 final english = NaturalLanguage.fromCode("Eng");
 print("${english.name}: ${english.codeShort}"); // Prints: "English: EN".

 final maybeCzech = NaturalLanguage.maybeFromValue(
   "CZE",
   where: (language) => language.bibliographicCode,
 );

 // This will print: "Native name: čeština".
 print("Native name: ${maybeCzech?.namesNative.first}");

 final indoEuropeanLanguages = NaturalLanguage.list.where(
   (language) => language.family is IndoEuropean,
 );
 // Prints a list of Indo-European languages:
 print(indoEuropeanLanguages);
 // (Language(name: Avestan), Language(name: Afrikaans),
 // ...
 // Language(name: Walloon), Language(name: Yiddish).

For more usage examples, please see the /example folder.

Additional information

For more information on using this package, check out the API documentation. If you have any issues or suggestions for the package, please file them in the GitHub repository.

References, credits and sources

• ISO
• Wikipedia
• Data Source¹