base58

commit 369b408991a98ad43b8f8c68e10464ffa44949e2
parent 70dc813a0f10c820a41727dddf02af89ce93212c
Author: Jared Tobin <jared@jtobin.io>
Date:   Sat, 10 Oct 2026 15:24:32 +0400

lib: build leading ones and zeros via replicate

Diffstat:
M
lib/Data/ByteString/Base58.hs
 | 
14
++------------

1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/lib/Data/ByteString/Base58.hs b/lib/Data/ByteString/Base58.hs
@@ -64,21 +64,11 @@ base58_charset = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
 
 -- produce leading ones from leading zeros
 leading_ones :: BS.ByteString -> BS.ByteString
-leading_ones = go mempty where
-  go acc bs = case BS.uncons bs of
-    Nothing -> acc
-    Just (h, t)
-      | h == 0 -> go (BS.cons 0x31 acc) t
-      | otherwise -> acc
+leading_ones bs = BS.replicate (BS.length (BS.takeWhile (== 0x00) bs)) 0x31
 
 -- produce leading zeros from leading ones
 leading_zeros :: BS.ByteString -> BS.ByteString
-leading_zeros = go mempty where
-  go acc bs = case BS.uncons bs of
-    Nothing -> acc
-    Just (h, t)
-      | h == 0x31 -> go (BS.cons 0x00 acc) t
-      | otherwise -> acc
+leading_zeros bs = BS.replicate (BS.length (BS.takeWhile (== 0x31) bs)) 0x00
 
 -- to base256
 unroll_base256 :: Integer -> BS.ByteString