Add resistor-color-duo

config.json

@@ -982,6 +982,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "resistor-color-duo",
+        "name": "Resistor Color Duo",
+        "uuid": "3678ff1c-79de-47bc-9219-80268cde53ce",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "reverse-string",
         "name": "Reverse String",

exercises/practice/resistor-color-duo/.docs/instructions.md

@@ -0,0 +1,33 @@
+# Instructions
+
+If you want to build something using a Raspberry Pi, you'll probably use _resistors_.
+For this exercise, you need to know two things about them:
+
+- Each resistor has a resistance value.
+- Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
+
+To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values.
+Each band has a position and a numeric value.
+
+The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.
+For example, if they printed a brown band (value 1) followed by a green band (value 5), it would translate to the number 15.
+
+In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands.
+The program will take color names as input and output a two digit number, even if the input is more than two colors!
+
+The band colors are encoded as follows:
+
+- black: 0
+- brown: 1
+- red: 2
+- orange: 3
+- yellow: 4
+- green: 5
+- blue: 6
+- violet: 7
+- grey: 8
+- white: 9
+
+From the example above:
+brown-green should return 15, and
+brown-green-violet should return 15 too, ignoring the third color.

exercises/practice/resistor-color-duo/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "src/resistor_color_duo.erl"
+    ],
+    "test": [
+      "test/resistor_color_duo_tests.erl"
+    ],
+    "example": [
+      ".meta/example.erl"
+    ]
+  },
+  "blurb": "Convert color codes, as used on resistors, to a numeric value.",
+  "source": "Maud de Vries, Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/1464"
+}

exercises/practice/resistor-color-duo/.meta/example.erl

@@ -0,0 +1,18 @@
+-module(example).
+
+-export([value/1]).
+
+
+value([First, Second | _]) ->
+    color_code(First) * 10 + color_code(Second).
+
+color_code(black) -> 0;
+color_code(brown) -> 1;
+color_code(red) -> 2;
+color_code(orange) -> 3;
+color_code(yellow) -> 4;
+color_code(green) -> 5;
+color_code(blue) -> 6;
+color_code(violet) -> 7;
+color_code(grey) -> 8;
+color_code(white) -> 9.

exercises/practice/resistor-color-duo/.meta/tests.toml

@@ -0,0 +1,31 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[ce11995a-5b93-4950-a5e9-93423693b2fc]
+description = "Brown and black"
+
+[7bf82f7a-af23-48ba-a97d-38d59406a920]
+description = "Blue and grey"
+
+[f1886361-fdfd-4693-acf8-46726fe24e0c]
+description = "Yellow and violet"
+
+[b7a6cbd2-ae3c-470a-93eb-56670b305640]
+description = "White and red"
+
+[77a8293d-2a83-4016-b1af-991acc12b9fe]
+description = "Orange and orange"
+
+[0c4fb44f-db7c-4d03-afa8-054350f156a8]
+description = "Ignore additional colors"
+
+[4a8ceec5-0ab4-4904-88a4-daf953a5e818]
+description = "Black and brown, one-digit"

exercises/practice/resistor-color-duo/rebar.config

@@ -0,0 +1,30 @@
+%% Erlang compiler options
+{erl_opts, [debug_info, warnings_as_errors]}.
+
+{deps, [{erl_exercism, "0.1.2"}]}.
+
+{dialyzer, [
+  {warnings, [underspecs, no_return]},
+  {get_warnings, true},
+  {plt_apps, top_level_deps}, % top_level_deps | all_deps
+  {plt_extra_apps, []},
+  {plt_location, local}, % local | "/my/file/name"
+  {plt_prefix, "rebar3"},
+  {base_plt_apps, [stdlib, kernel, crypto]},
+  {base_plt_location, global}, % global | "/my/file/name"
+  {base_plt_prefix, "rebar3"}
+]}.
+
+%% eunit:test(Tests)
+{eunit_tests, []}.
+%% Options for eunit:test(Tests, Opts)
+{eunit_opts, [verbose]}.
+
+%% == xref ==
+
+{xref_warnings, true}.
+
+%% xref checks to run
+{xref_checks, [undefined_function_calls, undefined_functions,
+  locals_not_used, exports_not_used,
+  deprecated_function_calls, deprecated_functions]}.

exercises/practice/resistor-color-duo/src/resistor_color_duo.app.src

@@ -0,0 +1,9 @@
+{application, resistor_color_duo,
+  [{description, "exercism.io - resistor color duo"},
+    {vsn, "0.0.1"},
+    {modules, []},
+    {registered, []},
+    {applications, [kernel,
+      stdlib]},
+    {env, []}
+  ]}.

exercises/practice/resistor-color-duo/src/resistor_color_duo.erl

@@ -0,0 +1,7 @@
+-module(resistor_color_duo).
+
+-export([value/1]).
+
+
+value(_Colors) ->
+    undefined.

exercises/practice/resistor-color-duo/test/resistor_color_duo_tests.erl

@@ -0,0 +1,35 @@
+-module(resistor_color_duo_tests).
+
+-include_lib("erl_exercism/include/exercism.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+
+
+
+'1_brown_and_black_test_'() ->
+    {"brown and black",
+     ?_assertMatch(10, resistor_color_duo:value([brown, black]))}.
+
+'2_blue_and_grey_test_'() ->
+    {"blue and grey",
+     ?_assertMatch(68, resistor_color_duo:value([blue, grey]))}.
+
+'3_yellow_and_violet_test_'() ->
+    {"yellow and violet",
+     ?_assertMatch(47, resistor_color_duo:value([yellow, violet]))}.
+
+'4_white_and_red_test_'() ->
+    {"white and red",
+     ?_assertMatch(92, resistor_color_duo:value([white, red]))}.
+
+'5_orange_and_orange_test_'() ->
+    {"orange and orange",
+     ?_assertMatch(33, resistor_color_duo:value([orange, orange]))}.
+
+'6_ignore_additional_colors_test_'() ->
+    {"ignore additional colors",
+     ?_assertMatch(51, resistor_color_duo:value([green, brown, orange]))}.
+
+'7_black_and_brown_one_digit_test_'() ->
+    {"black and brown, one-digit",
+     ?_assertMatch(1, resistor_color_duo:value([black, brown]))}.