From d32767dcb4198234733395edddba3753834879fa Mon Sep 17 00:00:00 2001
From: Peter Lemenkov <lemenkov@gmail.com>
Date: Sat, 16 Jun 2012 23:52:50 +0400
Subject: [PATCH 1/2] Rewrote hex routines under MIT license

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
---
 src/hex.erl |   56 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 28 insertions(+), 28 deletions(-)

diff --git a/src/hex.erl b/src/hex.erl
index 77e4224..e36528b 100644
--- a/src/hex.erl
+++ b/src/hex.erl
@@ -1,35 +1,35 @@
-%% from http://necrobious.blogspot.com/2008/03/binary-to-hex-string-back-to-binary-in.html
+%% -------------------------------------------------------------------
+%%
+%% Copyright (c) 2012 Peter Lemenkov.
+%%
+%% The MIT License
+%%
+%% Permission is hereby granted, free of charge, to any person obtaining a copy
+%% of this software and associated documentation files (the "Software"), to deal
+%% in the Software without restriction, including without limitation the rights
+%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+%% copies of the Software, and to permit persons to whom the Software is
+%% furnished to do so, subject to the following conditions:
+%%
+%% The above copyright notice and this permission notice shall be included in
+%% all copies or substantial portions of the Software.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+%% THE SOFTWARE.
+%%
+%% -------------------------------------------------------------------
 
 -module(hex).
 -export([bin_to_hexstr/1,hexstr_to_bin/1]).
 
-hex(N) when N < 10 ->
-    $0+N;
-hex(N) when N >= 10, N < 16 ->
-    $a+(N-10).
-
-int(C) when $0 =< C, C =< $9 ->
-    C - $0;
-int(C) when $A =< C, C =< $F ->
-    C - $A + 10;
-int(C) when $a =< C, C =< $f ->
-    C - $a + 10.
-    
-to_hex(N) when N < 256 ->
-    [hex(N div 16), hex(N rem 16)].
- 
-list_to_hexstr([]) -> 
-    [];
-list_to_hexstr([H|T]) ->
-    to_hex(H) ++ list_to_hexstr(T).
-
 bin_to_hexstr(Bin) ->
-    list_to_hexstr(binary_to_list(Bin)).
+    lists:flatten([(fun(X) when X =< 16 -> [$0 | integer_to_list(X, 16)]; (X) -> integer_to_list(X, 16) end)(Y) || <<Y:8>> <= Bin]).
 
 hexstr_to_bin(S) ->
-    list_to_binary(hexstr_to_list(S)).
-
-hexstr_to_list([X,Y|T]) ->
-    [int(X)*16 + int(Y) | hexstr_to_list(T)];
-hexstr_to_list([]) ->
-    [].
\ No newline at end of file
+    {ok, [N], []} = io_lib:fread("~16u", S),
+    binary:encode_unsigned(N).
-- 
1.7.10.2