Improve {furigana} marker for anki export

1 files changed, 78 insertions, 0 deletions

diff --git a/ext/mixed/js/japanese.js b/ext/mixed/js/japanese.js
index c11e955b..a8f72059 100644
--- a/ext/mixed/js/japanese.js
+++ b/ext/mixed/js/japanese.js
@@ -38,3 +38,81 @@ function jpKatakanaToHiragana(text) {
 
     return result;
 }
+
+function distributeFurigana(word, reading) { 
+    reading = reading || wanakana.toHiragana(word); 
+    function span(str, pred) { 
+        let i = 0; 
+        while (i < str.length && pred(str[i])) { 
+            i++; 
+        } 
+        return [str.substring(0, i), str.substring(i)]; 
+    } 
+    const isKanji = c => jpIsKanji(c) || 
+        c == "\u3005"; /* kurikaeshi */ 
+    const isKana = c => jpIsKana(c) || 
+        c == "\u30fc"; /* chouonpu */ 
+    function parse(word) { 
+        const res = []; 
+        while (word.length > 0) { 
+            const c = word.charAt(0); 
+            if (isKana(c)) { 
+                const [text, rest] = span(word, isKana); 
+                res.push({ type: "kana", text }); 
+                word = rest; 
+            } else if (isKanji(c)) { 
+                const [text, rest] = span(word, isKanji); 
+                res.push({ type: "kanji", text }); 
+                word = rest; 
+            } else return null; 
+        } 
+        return res; 
+    } 
+ 
+    let fallback = () => [{ text: word, furigana: reading }]; 
+    let parts = parse(word); 
+    if (parts == null) return fallback(); 
+    let parti = 0; 
+    let readingi = 0; 
+    let res = []; 
+    let current = null; 
+    function backtrack() { 
+        parti--; 
+        const prev = res.pop(); 
+        current = prev.furigana; 
+    } 
+    while (parti < parts.length) { 
+        const part = parts[parti]; 
+        switch (part.type) { 
+            case 'kana': 
+                if (reading.startsWith(wanakana.toHiragana(part.text), readingi)) { 
+                    if (parti == parts.length - 1 && readingi != reading.length - part.text.length) { 
+                        backtrack(); 
+                    } else { 
+                        readingi += part.text.length; 
+                        res.push({ text: part.text }); 
+                        parti++; 
+                    } 
+                } else backtrack(); 
+                break; 
+            case "kanji": 
+                current = current || ""; 
+                if (parti == parts.length - 1) { 
+                    // last part, consume all 
+                    current += reading.substring(readingi); 
+                } else { 
+                    const nextText = parts[parti + 1].text; 
+                    let end = reading.indexOf(nextText, readingi + 1); // consume at least one character 
+                    if (end == -1) { 
+                        return fallback(); 
+                    } 
+                    current += reading.substring(readingi, end); 
+                    readingi = end; 
+                } 
+                res.push({ text: part.text, furigana: current }); 
+                current = null; 
+                parti++; 
+        } 
+    } 
+    return res;
+}