decode support

[rfc1751] / rfc1751.py

diff --git a/rfc1751.py b/rfc1751.py
index 70bae6e5c91a7a95469d5e348886f608d322a7cb..70f5b3a64e469c0faed2ad37509474989f991368 100644 (file)
--- a/rfc1751.py
+++ b/rfc1751.py
@@ -18,7 +18,8 @@ import sys
 from rfc1751wordlist import WORD_LIST, WORD_LIST_SIZE
 
 
-# TODO: Decode
+WORD_LIST_INVERTED = {word: i for (i, word) in enumerate(WORD_LIST)}
+assert len(WORD_LIST_INVERTED) == WORD_LIST_SIZE
 
 
 def encode_actual(x: int) -> list[str]:
@@ -30,8 +31,18 @@ def encode(x: int) -> list[str]:
     return [WORD_LIST[x]] if x == 0 else encode_actual(x)
 
 
+def decode(x: list[str]) -> int:
+    return WORD_LIST_SIZE * decode(x[:-1]) + \
+        WORD_LIST_INVERTED[x[-1]] if x else 0
+
+
 def main() -> None:
-    print(' '.join(encode(int(sys.argv[1]))))
+    if sys.argv[1].isnumeric():
+        print(' '.join(encode(int(sys.argv[1]))))
+    elif len(sys.argv) == 2:
+        print(decode(sys.argv[1].split(' ')))
+    else:
+        print(decode(sys.argv[1:]))
 
 
 if __name__ == '__main__':