Add resistor-color-duo exercise

config.json

@@ -217,6 +217,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "resistor-color-duo",
+        "name": "Resistor Color Duo",
+        "uuid": "e4b8a28c-56e7-4fec-9fe9-d52902743153",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "rotational-cipher",
         "name": "Rotational Cipher",

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": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "resistor_color_duo.fut"
+    ],
+    "test": [
+      "test.fut"
+    ],
+    "example": [
+      ".meta/example.fut"
+    ]
+  },
+  "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.fut

@@ -0,0 +1,22 @@
+def equal [m] [n] (first: [m]u8) (second: [n]u8): bool =
+  if m != n then false else
+  let same = loop same = true for i < n do
+    same && (first[i] == second[i])
+  in
+    same
+
+def colorCode (color: []u8): i32 =
+  if equal color "black" then 0 else
+  if equal color "brown" then 1 else
+  if equal color "red" then 2 else
+  if equal color "orange" then 3 else
+  if equal color "yellow" then 4 else
+  if equal color "green" then 5 else
+  if equal color "blue" then 6 else
+  if equal color "violet" then 7 else
+  if equal color "grey" then 8 else
+  if equal color "white" then 9 else
+  assert false 0
+
+def value (first: []u8) (second: []u8): i32 =
+  10 * (colorCode first) + (colorCode second)

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/resistor_color_duo.fut

@@ -0,0 +1 @@
+def value (first: []u8) (second: []u8): i32 = ???

exercises/practice/resistor-color-duo/test.fut

@@ -0,0 +1,39 @@
+import "resistor_color_duo"
+
+-- Brown and black
+-- ==
+-- input { "brown" "black" }
+-- output { 10 }
+
+-- Blue and grey
+-- ==
+-- input { "blue" "grey" }
+-- output { 68 }
+
+-- Yellow and violet
+-- ==
+-- input { "yellow" "violet" }
+-- output { 47 }
+
+-- White and red
+-- ==
+-- input { "white" "red" }
+-- output { 92 }
+
+-- Orange and orange
+-- ==
+-- input { "orange" "orange" }
+-- output { 33 }
+
+-- Ignore additional colors
+-- ==
+-- input { "green" "brown" }
+-- output { 51 }
+
+-- Black and brown, one-digit
+-- ==
+-- input { "black" "brown" }
+-- output { 1 }
+
+let main (first: []u8) (second: []u8): i32 =
+  value first second

generators/exercises/resistor_color_duo.py

@@ -0,0 +1,11 @@
+def gen_test_case(prop, description, inp, expected, f):
+    colors = inp["colors"]
+    f.write(f"-- {description}\n")
+    f.write("-- ==\n")
+    f.write(f'-- input {{ "{colors[0]}" "{colors[1]}" }}\n')
+    f.write(f"-- output {{ {expected} }}\n\n")
+
+
+def gen_main(f):
+    f.write("let main (first: []u8) (second: []u8): i32 =\n")
+    f.write("  value first second\n")