2 files changed, 126 insertions, 9 deletions

diff --git a/ext/mixed/js/display-generator.js b/ext/mixed/js/display-generator.js
index 49afc44b..41f7315a 100644
--- a/ext/mixed/js/display-generator.js
+++ b/ext/mixed/js/display-generator.js
@@ -19,6 +19,7 @@
 /* global
  * TemplateHandler
  * apiGetDisplayTemplatesHtml
+ * jp
  */
 
 class DisplayGenerator {
@@ -283,7 +284,7 @@ class DisplayGenerator {
     _appendKanjiLinks(container, text) {
         let part = '';
         for (const c of text) {
-            if (DisplayGenerator._isCharacterKanji(c)) {
+            if (jp.isCodePointKanji(c.codePointAt(0))) {
                 if (part.length > 0) {
                     container.appendChild(document.createTextNode(part));
                     part = '';
@@ -300,14 +301,6 @@ class DisplayGenerator {
         }
     }
 
-    static _isCharacterKanji(c) {
-        const code = c.codePointAt(0);
-        return (
-            code >= 0x4e00 && code < 0x9fb0 ||
-            code >= 0x3400 && code < 0x4dc0
-        );
-    }
-
     static _appendMultiple(container, createItem, detailsArray, fallback=[]) {
         if (container === null) { return 0; }
 
diff --git a/ext/mixed/js/japanese.js b/ext/mixed/js/japanese.js
new file mode 100644
index 00000000..61a247b2
--- /dev/null
+++ b/ext/mixed/js/japanese.js
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * 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/>.
+ */
+
+const jp = (() => {
+    const HIRAGANA_RANGE = [0x3040, 0x309f];
+    const KATAKANA_RANGE = [0x30a0, 0x30ff];
+    const KANA_RANGES = [HIRAGANA_RANGE, KATAKANA_RANGE];
+
+    const CJK_UNIFIED_IDEOGRAPHS_RANGE = [0x4e00, 0x9fff];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A_RANGE = [0x3400, 0x4dbf];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B_RANGE = [0x20000, 0x2a6df];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C_RANGE = [0x2a700, 0x2b73f];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D_RANGE = [0x2b740, 0x2b81f];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E_RANGE = [0x2b820, 0x2ceaf];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_F_RANGE = [0x2ceb0, 0x2ebef];
+    const CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT_RANGE = [0x2f800, 0x2fa1f];
+    const CJK_UNIFIED_IDEOGRAPHS_RANGES = [
+        CJK_UNIFIED_IDEOGRAPHS_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_F_RANGE,
+        CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT_RANGE
+    ];
+
+    // Japanese character ranges, roughly ordered in order of expected frequency
+    const JAPANESE_RANGES = [
+        HIRAGANA_RANGE,
+        KATAKANA_RANGE,
+
+        ...CJK_UNIFIED_IDEOGRAPHS_RANGES,
+
+        [0xff66, 0xff9f], // Halfwidth katakana
+
+        [0x30fb, 0x30fc], // Katakana punctuation
+        [0xff61, 0xff65], // Kana punctuation
+        [0x3000, 0x303f], // CJK punctuation
+
+        [0xff10, 0xff19], // Fullwidth numbers
+        [0xff21, 0xff3a], // Fullwidth upper case Latin letters
+        [0xff41, 0xff5a], // Fullwidth lower case Latin letters
+
+        [0xff01, 0xff0f], // Fullwidth punctuation 1
+        [0xff1a, 0xff1f], // Fullwidth punctuation 2
+        [0xff3b, 0xff3f], // Fullwidth punctuation 3
+        [0xff5b, 0xff60], // Fullwidth punctuation 4
+        [0xffe0, 0xffee]  // Currency markers
+    ];
+
+
+    // Character code testing functions
+
+    function isCodePointKanji(codePoint) {
+        return isCodePointInRanges(codePoint, CJK_UNIFIED_IDEOGRAPHS_RANGES);
+    }
+
+    function isCodePointKana(codePoint) {
+        return isCodePointInRanges(codePoint, KANA_RANGES);
+    }
+
+    function isCodePointJapanese(codePoint) {
+        return isCodePointInRanges(codePoint, JAPANESE_RANGES);
+    }
+
+    function isCodePointInRanges(codePoint, ranges) {
+        for (const [min, max] of ranges) {
+            if (codePoint >= min && codePoint <= max) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    // String testing functions
+
+    function isStringEntirelyKana(str) {
+        if (str.length === 0) { return false; }
+        for (const c of str) {
+            if (!isCodePointKana(c.codePointAt(0))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    function isStringPartiallyJapanese(str) {
+        if (str.length === 0) { return false; }
+        for (const c of str) {
+            if (isCodePointJapanese(c.codePointAt(0))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    // Exports
+
+    return {
+        isCodePointKanji,
+        isCodePointKana,
+        isCodePointJapanese,
+        isStringEntirelyKana,
+        isStringPartiallyJapanese
+    };
+})();