From 5585bfe12d9ec48a7993f04fb0c87eaacb9436f1 Mon Sep 17 00:00:00 2001
From: MrZ_26 <1046101471@qq.com>
Date: Wed, 28 Sep 2022 00:42:05 +0800
Subject: [PATCH] little optimization on hex2bin and bin2hex

---
 sha2.lua | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/sha2.lua b/sha2.lua
index 201f52e..a56b1ae 100644
--- a/sha2.lua
+++ b/sha2.lua
@@ -4706,20 +4706,18 @@ end
 
 local hex_to_bin, bin_to_hex, bin_to_base64, base64_to_bin
 do
+   local function repl_hex2bin(hh)
+      return char(tonumber(hh, 16))
+   end
    function hex_to_bin(hex_string)
-      return (gsub(hex_string, "%x%x",
-         function (hh)
-            return char(tonumber(hh, 16))
-         end
-      ))
+      return (gsub(hex_string, "%x%x", repl_hex2bin))
    end
 
+   local function repl_bin2hex(c)
+      return string_format("%02x", byte(c))
+   end
    function bin_to_hex(binary_string)
-      return (gsub(binary_string, ".",
-         function (c)
-            return string_format("%02x", byte(c))
-         end
-      ))
+      return (gsub(binary_string, ".", repl_bin2hex))
    end
 
    local base64_symbols = {