add kansuji converter

akaza-im · Jan 30, 2023 · 7ec44cf · 7ec44cf
1 parent b5d3571
commit 7ec44cf
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diff --git a/libakaza/src/kansuji.rs b/libakaza/src/kansuji.rs
@@ -0,0 +1,80 @@
+use std::cmp::min;
+
+const NUMS: [&str; 10] = ["", "一", "二", "三", "四", "五", "六", "七", "八", "九"];
+const SUBS: [&str; 4] = ["", "十", "百", "千"];
+const PARTS: [&str; 18] = [
+    "",
+    "万",
+    "億",
+    "兆",
+    "京",
+    "垓",
+    "𥝱",
+    "穣",
+    "溝",
+    "澗",
+    "正",
+    "載",
+    "極",
+    "恒河沙",
+    "阿僧祇",
+    "那由他",
+    "不可思議",
+    "無量大数",
+];
+
+fn int2kanji(i: i64) -> String {
+    let s = i.to_string();
+    let chars = s.bytes();
+    let p = chars.into_iter().rev().enumerate().collect::<Vec<_>>();
+    let mut buf: Vec<&'static str> = Vec::new();
+    for (i, b) in p.clone() {
+        let c = (b - 48) as usize; // 48 is '0'
+        if i % 4 == 0
+            && i > 0
+            && (i..min(i + 4, s.len()))
+                .map(|i| {
+                    let (_, c) = p.get(i).unwrap();
+                    *c
+                })
+                .any(|n| n != 48)
+        {
+            buf.push(PARTS[i / 4]);
+        }
+        if c != 0 {
+            // その桁が 0 のときは区切りを追加しない
+            buf.push(SUBS[i % 4]);
+        }
+        if !(i % 4 != 0 && c == 1) {
+            // 十百千を表示したときで、一のときは追加しない。
+            buf.push(NUMS[c]); // 48 is '0'
+        }
+    }
+    buf.reverse();
+    buf.join("")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_int2kanji() {
+        assert_eq!(int2kanji(1), "一");
+        assert_eq!(int2kanji(9), "九");
+        assert_eq!(int2kanji(10), "十");
+        assert_eq!(int2kanji(11), "十一");
+        assert_eq!(int2kanji(21), "二十一");
+        assert_eq!(int2kanji(99), "九十九");
+        assert_eq!(int2kanji(100), "百");
+        assert_eq!(int2kanji(999), "九百九十九");
+        assert_eq!(int2kanji(1000), "千");
+        assert_eq!(int2kanji(9999), "九千九百九十九");
+        assert_eq!(int2kanji(10000), "一万");
+        assert_eq!(int2kanji(10020), "一万二十");
+        assert_eq!(int2kanji(1_000_020), "百万二十");
+        assert_eq!(int2kanji(100_000_020), "一億二十");
+        assert_eq!(int2kanji(1_0000_4423), "一億四千四百二十三");
+        assert_eq!(int2kanji(1_8000_4423), "一億八千万四千四百二十三");
+    }
+}
diff --git a/libakaza/src/lib.rs b/libakaza/src/lib.rs
@@ -12,6 +12,7 @@ pub mod extend_clause;
 pub mod graph;
 pub mod kana_kanji;
 pub mod kana_trie;
+pub mod kansuji;
 pub mod keymap;
 pub mod lm;
 mod resource;