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vendor/yomitan/js/language/text-utilities.js

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+/*
+ * Copyright (C) 2024-2025  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import {isStringPartiallyJapanese} from './ja/japanese.js';
+import {isStringPartiallyChinese} from './zh/chinese.js';
+
+/**
+ * Returns the language that the string might be by using some heuristic checks.
+ * Values returned are ISO codes. `null` is returned if no language can be determined.
+ * @param {string} text
+ * @param {?string} language
+ * @returns {?string}
+ */
+export function getLanguageFromText(text, language) {
+    const partiallyJapanese = isStringPartiallyJapanese(text);
+    const partiallyChinese = isStringPartiallyChinese(text);
+    if (!['zh', 'yue'].includes(language ?? '')) {
+        if (partiallyJapanese) { return 'ja'; }
+        if (partiallyChinese) { return 'zh'; }
+    }
+    return language;
+}