Add isogram exercise

config.json

@@ -129,6 +129,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "isogram",
+        "name": "Isogram",
+        "uuid": "5b4e8590-7aed-40d3-b337-23f0c1db9d5b",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "luhn",
         "name": "Luhn",

exercises/practice/isogram/.docs/instructions.md

@@ -0,0 +1,14 @@
+# Instructions
+
+Determine if a word or phrase is an isogram.
+
+An isogram (also known as a "non-pattern word") is a word or phrase without a repeating letter, however spaces and hyphens are allowed to appear multiple times.
+
+Examples of isograms:
+
+- lumberjacks
+- background
+- downstream
+- six-year-old
+
+The word _isograms_, however, is not an isogram, because the s repeats.

exercises/practice/isogram/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "isogram.coffee"
+    ],
+    "test": [
+      "isogram.spec.coffee"
+    ],
+    "example": [
+      ".meta/example.coffee"
+    ]
+  },
+  "blurb": "Determine if a word or phrase is an isogram.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Isogram"
+}

exercises/practice/isogram/.meta/example.coffee

@@ -0,0 +1,13 @@
+class Isogram
+  @isIsogram: (phrase) ->
+    seen = {}
+    for char in phrase.toLowerCase()
+        cp = char.charCodeAt(0)
+        if cp >= 97 && cp <= 122
+            if char of seen
+                return false
+
+            seen[char] = true
+    true
+
+module.exports = Isogram

exercises/practice/isogram/.meta/tests.toml

@@ -0,0 +1,52 @@
+# 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.
+
+[a0e97d2d-669e-47c7-8134-518a1e2c4555]
+description = "empty string"
+
+[9a001b50-f194-4143-bc29-2af5ec1ef652]
+description = "isogram with only lower case characters"
+
+[8ddb0ca3-276e-4f8b-89da-d95d5bae78a4]
+description = "word with one duplicated character"
+
+[6450b333-cbc2-4b24-a723-0b459b34fe18]
+description = "word with one duplicated character from the end of the alphabet"
+
+[a15ff557-dd04-4764-99e7-02cc1a385863]
+description = "longest reported english isogram"
+
+[f1a7f6c7-a42f-4915-91d7-35b2ea11c92e]
+description = "word with duplicated character in mixed case"
+
+[14a4f3c1-3b47-4695-b645-53d328298942]
+description = "word with duplicated character in mixed case, lowercase first"
+
+[423b850c-7090-4a8a-b057-97f1cadd7c42]
+description = "hypothetical isogrammic word with hyphen"
+
+[93dbeaa0-3c5a-45c2-8b25-428b8eacd4f2]
+description = "hypothetical word with duplicated character following hyphen"
+
+[36b30e5c-173f-49c6-a515-93a3e825553f]
+description = "isogram with duplicated hyphen"
+
+[cdabafa0-c9f4-4c1f-b142-689c6ee17d93]
+description = "made-up name that is an isogram"
+
+[5fc61048-d74e-48fd-bc34-abfc21552d4d]
+description = "duplicated character in the middle"
+
+[310ac53d-8932-47bc-bbb4-b2b94f25a83e]
+description = "same first and last characters"
+
+[0d0b8644-0a1e-4a31-a432-2b3ee270d847]
+description = "word with duplicated character and with two hyphens"

exercises/practice/isogram/isogram.coffee

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+class Isogram
+  @isIsogram: (phrase) ->
+
+module.exports = Isogram

exercises/practice/isogram/isogram.spec.coffee

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+Isogram = require './isogram'
+
+describe 'Isogram', ->
+  it 'empty string', ->
+    phrase = ''
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'isogram with only lower case characters', ->
+    phrase = 'isogram'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'word with one duplicated character', ->
+    phrase = 'eleven'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'word with one duplicated character from the end of the alphabet', ->
+    phrase = 'zzyzx'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'longest reported english isogram', ->
+    phrase = 'subdermatoglyphic'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'word with duplicated character in mixed case', ->
+    phrase = 'Alphabet'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'word with duplicated character in mixed case, lowercase first', ->
+    phrase = 'alphAbet'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'hypothetical isogrammic word with hyphen', ->
+    phrase = 'thumbscrew-japingly'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'hypothetical word with duplicated character following hyphen', ->
+    phrase = 'thumbscrew-jappingly'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'isogram with duplicated hyphen', ->
+    phrase = 'six-year-old'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'made-up name that is an isogram', ->
+    phrase = 'Emily Jung Schwartzkopf'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual true
+
+  xit 'duplicated character in the middle', ->
+    phrase = 'accentor'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'same first and last characters', ->
+    phrase = 'angola'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false
+
+  xit 'word with duplicated character and with two hyphens', ->
+    phrase = 'up-to-date'
+    result = Isogram.isIsogram(phrase)
+    expect(result).toEqual false