google-closure-library
Version:
Google's common JavaScript library
60 lines (51 loc) • 1.91 kB
JavaScript
/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Contains helper functions for performing locale-sensitive
* collation.
*/
goog.provide('goog.i18n.collation');
/**
* Returns the comparator for a locale. If a locale is not explicitly specified,
* a comparator for the user's locale will be returned. Note that if the browser
* does not support locale-sensitive string comparisons, the comparator returned
* will be a simple codepoint comparator.
*
* @param {string=} opt_locale the locale that the comparator is used for.
* @param {{usage: (string|undefined), localeMatcher: (string|undefined),
* sensitivity: (string|undefined), ignorePunctuation: (boolean|undefined),
* numeric: (boolean|undefined), caseFirst: (string|undefined)}=}
* opt_options the optional set of options for use with the native
* collator.
* @return {function(string, string): number} The locale-specific comparator.
*/
goog.i18n.collation.createComparator = function(opt_locale, opt_options) {
'use strict';
// See http://code.google.com/p/v8-i18n.
if (goog.i18n.collation.hasNativeComparator()) {
const intl = goog.global.Intl;
return new intl.Collator([opt_locale || goog.LOCALE], opt_options || {})
.compare;
} else {
return function(arg1, arg2) {
'use strict';
return arg1.localeCompare(arg2);
};
}
};
/**
* Returns true if a locale-sensitive comparator is available for a locale. If
* a locale is not explicitly specified, the user's locale is used instead.
*
* @return {boolean} Whether there is a locale-sensitive comparator available
* for the locale.
*/
goog.i18n.collation.hasNativeComparator = function() {
'use strict';
if (goog.FEATURESET_YEAR >= 2019) return true;
const intl = goog.global.Intl;
return !!(intl && intl.Collator);
};