hanja: add single-character dictionary data

map/libhangul2hanja

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+"""Extract single-character Hanja readings from libhangul data."""
+
+import sys
+from pathlib import Path
+
+
+def ishangul(s):
+    return len(s) == 1 and 0xAC00 <= ord(s) <= 0xD7A3
+
+
+def ishanja(s):
+    if len(s) != 1:
+        return False
+    c = ord(s)
+    return (0x3400 <= c <= 0x4DBF
+            or 0x4E00 <= c <= 0x9FFF
+            or 0xF900 <= c <= 0xFAFF)
+
+
+def extract(src, name):
+    comments = []
+    entries = []
+    seen = set()
+    leading = True
+    for lineno, raw in enumerate(src, 1):
+        line = raw.rstrip("\r\n")
+        if not line:
+            continue
+        if line.startswith("#"):
+            if leading:
+                comments.append(line.rstrip())
+            continue
+        leading = False
+        fields = line.split(":")
+        if len(fields) != 3:
+            raise ValueError(f"{name}:{lineno}: need key:value:comment")
+        reading, hanja, _ = fields
+        if not ishangul(reading) or not ishanja(hanja):
+            continue
+        pair = (hanja, reading)
+        if pair in seen:
+            raise ValueError(f"{name}:{lineno}: duplicate Hanja reading")
+        seen.add(pair)
+        entries.append(pair)
+    if not entries:
+        raise ValueError(f"{name}: no single-character Hanja readings")
+    return comments, entries
+
+
+def main():
+    if len(sys.argv) > 2:
+        print(f"usage: {sys.argv[0]} [libhangul-hanja.txt]", file=sys.stderr)
+        return 2
+    src = sys.stdin
+    name = "<stdin>"
+    try:
+        if len(sys.argv) == 2:
+            name = sys.argv[1]
+            src = Path(name).open(encoding="utf-8")
+        comments, entries = extract(src, name)
+        for line in comments:
+            print(line)
+        if comments:
+            print()
+        for hanja, reading in entries:
+            print(f"{hanja}\t{reading}")
+    except (OSError, UnicodeError, ValueError) as error:
+        print(error, file=sys.stderr)
+        return 1
+    finally:
+        if src is not sys.stdin:
+            src.close()
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())