Prepare a new hex package

esl · May 19, 2021 · 94f27b4 · 94f27b4
1 parent 08c96ac
commit 94f27b4
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Showing 3 changed files with 40 additions and 11 deletions.
diff --git a/README.md b/README.md
@@ -1,10 +1,11 @@
 Base16 encoding and decoding
 ============================
 
-[![Hex](http://img.shields.io/hexpm/v/fast_base16.svg)](https://hex.pm/packages/fast_base16)
+[![Actions Status](https://github.com/esl/base16/workflows/ci/badge.svg)](https://github.com/esl/base16/actions)
+[![codecov](https://codecov.io/gh/esl/base16/branch/main/graph/badge.svg)](https://codecov.io/gh/esl/base16)
+[![Hex](http://img.shields.io/hexpm/v/base16.svg)](https://hex.pm/packages/base16)
 
-API
----
+## API
 
 Both `encode/1` and `decode/1` functions are of `(binary()) -> binary()` type.
 
@@ -19,15 +20,17 @@ B = base16:decode(H).
 Please, note:
 
    * `base16:encode/1` returns lower-case letters.
-   * `base16:decode/1` requires the argument to be a binary of odd-number size, and it parses both
-     in upper-case or lower-case encoding.
+   * `base16:decode/1` requires the argument to be a binary of odd-number size, and it parses both in upper-case or lower-case encoding.
 
 
-Implementation
---------------
+## Implementation
 
-Code is implemented using lookup tables, which tremendously speeds-up the algorithm and consumes
-constant memory. It's the fastest you can get using pure Erlang code!
+Code is implemented using lookup tables, which tremendously speeds-up the algorithm and consumes constant memory. It's the fastest you can get using pure Erlang code!
+
+## NOTE
+
+Note that, lookup tables also means that the code-size is bigger.
+If you're running on embedded, where smaller code-sizes are the actual best, you might benefit from using the version 1.0.0, both available on github and hex.
 
 
 License

diff --git a/src/base16.app.src b/src/base16.app.src
@@ -1,12 +1,11 @@
 {application, base16,
  [
   {description, "Base16 encoding and decoding"},
-  {vsn, "1.1.1"},
+  {vsn, git},
   {registered, []},
   {applications, [kernel, stdlib]},
   {env, []},
   {maintainers, ["ESL"]},
-  {pkg_name, "fast_base16"},
   {licenses, ["MIT", "GPL (for tests)"]},
   {links, [{"Github", "https://github.com/esl/base16"}]}
  ]}.
diff --git a/test/base16_tests.erl b/test/base16_tests.erl
@@ -35,6 +35,14 @@ prop_encode_decode() ->
             H2 =:= list_to_binary(string:to_lower(binary_to_list(H1)))
     end).
 
+prop_compare_algorithms_encode() ->
+    ?FORALL(B, binary(),
+            slow_encode(B) =:= base16:encode(B)).
+
+prop_compare_algorithms_decode() ->
+    ?FORALL(B, even_len_binary(hex_digit()),
+            slow_decode(B) =:= base16:decode(B)).
+
 encode_spec_test() ->
     proper:check_spec({base16, encode, 1}).
 
@@ -69,3 +77,22 @@ even_len_binary(Digit) ->
 
 even_len_list(Elem) ->
     ?SUCHTHAT(L, list(Elem), length(L) rem 2 =:= 0).
+
+
+%%--------------------------------------------------------------------
+%% Older algorithm
+%%--------------------------------------------------------------------
+-spec slow_encode(binary()) -> <<_:_*16>>.
+slow_encode(Data) ->
+    << <<(hex(N div 16)), (hex(N rem 16))>> || <<N>> <= Data >>.
+
+-spec slow_decode(<<_:_*16>>) -> binary().
+slow_decode(Base16) when size(Base16) rem 2 =:= 0 ->
+    << <<(unhex(H) bsl 4 + unhex(L))>> || <<H,L>> <= Base16 >>.
+
+hex(N) when N < 10 -> N + $0;
+hex(N) when N < 16 -> N - 10 + $a.
+
+unhex(D) when $0 =< D andalso D =< $9 -> D - $0;
+unhex(D) when $a =< D andalso D =< $f -> 10 + D - $a;
+unhex(D) when $A =< D andalso D =< $F -> 10 + D - $A.