first commit

index.js

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+var languageData = require( './language-data.json' );
+
+/**
+ * Utility functions for querying language data.
+ */
+
+/**
+ * Is this language a redirect to another language?
+ * @param {string} language  Language code
+ * @return {string} Target language code if it's a redirect or false if it's not
+ */
+function isRedirect( language ) {
+	return ( languageData.languages[ language ] !== undefined && languageData.languages[ language ].length === 1 ) ? languageData.languages[ language ][ 0 ] : false;
+}
+
+/**
+ * Returns the script of the language.
+ * @param {string} language Language code
+ * @return {string}
+ */
+function getScript( language ) {
+	var target = isRedirect( language );
+	if ( target ) {
+		return getScript( target );
+	}
+	if ( !languageData.languages[ language ] ) {
+		// Undetermined
+		return 'Zyyy';
+	}
+	return languageData.languages[ language ][ 0 ];
+}
+
+/**
+ * Returns the regions in which a language is spoken.
+ * @param {string} language Language code
+ * @return {string[]} 'UNKNOWN'
+ */
+function getRegions( language ) {
+	var target = isRedirect( language );
+	if ( target ) {
+		return getRegions( target );
+	}
+	return ( languageData.languages[ language ] && languageData.languages[ language ][ 1 ] ) || 'UNKNOWN';
+}
+
+/**
+ * Returns the autonym of the language.
+ * @param {string} language Language code
+ * @return {string}
+ */
+function getAutonym( language ) {
+	var target = isRedirect( language );
+	if ( target ) {
+		return getAutonym( target );
+	}
+	return ( languageData.languages[ language ] && languageData.languages[ language ][ 2 ] ) || language;
+}
+
+/**
+ * Returns all language codes and corresponding autonyms
+ * @return {array}
+ */
+function getAutonyms() {
+	var language,
+		autonymsByCode = {};
+	for ( language in languageData.languages ) {
+		if ( isRedirect( language ) ) {
+			continue;
+		}
+		autonymsByCode[ language ] = getAutonym( language );
+	}
+	return autonymsByCode;
+}
+
+/**
+ * Returns all languages written in the given scripts.
+ * @param {string[]} scripts
+ * @return {string[]} languages codes
+ */
+function getLanguagesInScripts( scripts ) {
+	var language, i,
+		languagesInScripts = [];
+	for ( language in languageData.languages ) {
+		if ( isRedirect( language ) ) {
+			continue;
+		}
+		for ( i = 0; i < scripts.length; i++ ) {
+			if ( scripts[ i ] === getScript( language ) ) {
+				languagesInScripts.push( language );
+				break;
+			}
+		}
+	}
+	return languagesInScripts;
+}
+
+/**
+ * Returns all languages written in script.
+ * @param {string} script
+ * @return {string[]} array of strings (languages codes)
+ */
+function getLanguagesInScript( script ) {
+	return getLanguagesInScripts( [ script ] );
+}
+
+/**
+ * Returns the script group of a script or 'Other' if it doesn't
+ * belong to any group.
+ * @param {string} script Script code
+ * @return {string} script group name
+ */
+function getGroupOfScript( script ) {
+	var scriptGroup;
+	for ( scriptGroup in languageData.scriptgroups ) {
+		if ( languageData.scriptgroups[ scriptGroup ].includes( script ) ) {
+			return scriptGroup;
+		}
+	}
+	return 'Other';
+}
+
+/**
+ * Returns the script group of a language.
+ * @param {string} language Language code
+ * @return {string} script group name
+ */
+function getScriptGroupOfLanguage( language ) {
+	return getGroupOfScript( getScript( language ) );
+}
+
+/**
+ * Get the given list of languages grouped by script.
+ * @param {string[]} languages Array of language codes
+ * @return {Object} Array of languages indexed by script codes
+ */
+function getLanguagesByScriptGroup( languages ) {
+	var languagesByScriptGroup = {},
+		language, resolvedRedirect, langScriptGroup;
+	for ( language in languages ) {
+		resolvedRedirect = isRedirect( language ) || language;
+		langScriptGroup = getScriptGroupOfLanguage( resolvedRedirect );
+		if ( !languagesByScriptGroup[ langScriptGroup ] ) {
+			languagesByScriptGroup[ langScriptGroup ] = [];
+		}
+		languagesByScriptGroup[ langScriptGroup ].push( language );
+	}
+	return languagesByScriptGroup;
+}
+
+/**
+ * Returns an associative array of languages in several regions,
+ * grouped by script group.
+ * @param {string[]} regions array of region codes
+ * @return {Object}
+ */
+function getLanguagesByScriptGroupInRegions( regions ) {
+	var language, i, scriptGroup,
+		languagesByScriptGroupInRegions = {};
+	for ( language in languageData.languages ) {
+		if ( isRedirect( language ) ) {
+			continue;
+		}
+		for ( i = 0; i < regions.length; i++ ) {
+			if ( getRegions( language ).includes( regions[ i ] ) ) {
+				scriptGroup = getScriptGroupOfLanguage( language );
+				if ( languagesByScriptGroupInRegions[ scriptGroup ] === undefined ) {
+					languagesByScriptGroupInRegions[ scriptGroup ] = [];
+				}
+				languagesByScriptGroupInRegions[ scriptGroup ].push( language );
+				break;
+			}
+		}
+	}
+	return languagesByScriptGroupInRegions;
+}
+
+/**
+ * Returns an associative array of languages in a region,
+ * grouped by script group.
+ * @param {string} region Region code
+ * @return {Object}
+ */
+function getLanguagesByScriptGroupInRegion( region ) {
+	return getLanguagesByScriptGroupInRegions( [ region ] );
+}
+
+/**
+ * A callback for sorting languages by autonym.
+ * Can be used as an argument to a sort function.
+ * @param {string} a Language code
+ * @param {string} b Language code
+ * @return {number}
+ */
+function sortByAutonym( a, b ) {
+	var autonymA = getAutonym( a ) || a,
+		autonymB = getAutonym( b ) || b;
+	return ( autonymA.toLowerCase() < autonymB.toLowerCase() ) ? -1 : 1;
+}
+
+/**
+ * Check if a language is right-to-left.
+ * @param {string} language Language code
+ * @return {boolean}
+ */
+function isRtl( language ) {
+	return languageData.rtlscripts.includes( getScript( language ) );
+}
+
+/**
+ * Return the direction of the language
+ * @param {string} language Language code
+ * @return {string}
+ */
+function getDir( language ) {
+	return isRtl( language ) ? 'rtl' : 'ltr';
+}
+
+/**
+ * Returns the languages spoken in a territory.
+ * @param {string} territory Territory code
+ * @return {string[]} list of language codes
+ */
+function getLanguagesInTerritory( territory ) {
+	return languageData.territories[ territory ];
+}
+
+/**
+ * Adds a language in run time and sets its options as provided.
+ * If the target option is provided, the language is defined as a redirect.
+ * Other possible options are script, regions and autonym.
+ *
+ * @param {string} code New language code.
+ * @param {Object} options Language properties.
+ */
+function addLanguage( code, options ) {
+	if ( options.target ) {
+		languageData.languages[ code ] = [ options.target ];
+	} else {
+		languageData.languages[ code ] = [ options.script, options.regions, options.autonym ];
+	}
+}
+
+module.exports = {
+	addLanguage,
+	getAutonym,
+	getAutonyms,
+	getDir,
+	getGroupOfScript,
+	getLanguagesByScriptGroup,
+	getLanguagesByScriptGroupInRegion,
+	getLanguagesByScriptGroupInRegions,
+	getLanguagesInScript,
+	getLanguagesInScripts,
+	getLanguagesInTerritory,
+	getRegions,
+	getScript,
+	getScriptGroupOfLanguage,
+	isRedirect,
+	isRtl,
+	sortByAutonym
+};