Add Pangram Exercise

config.json

@@ -28,6 +28,12 @@
       "topics": [
       ]
     },
+    {
+      "slug": "pangram",
+      "difficulty": 1,
+      "topics": [
+      ]
+    },
     {
       "slug": "run-length-encoding",
       "difficulty": 1,

exercises/pangram/examples/success-standard/package.yaml

@@ -0,0 +1,16 @@
+name: pangram
+
+dependencies:
+  - base
+
+library:
+  exposed-modules: Pangram
+  source-dirs: src
+
+tests:
+  test:
+    main: Tests.hs
+    source-dirs: test
+    dependencies:
+      - pangram
+      - hspec

exercises/pangram/examples/success-standard/src/Pangram.hs

@@ -0,0 +1,7 @@
+module Pangram (isPangram) where
+
+import Data.Char (toLower)
+
+isPangram :: String -> Bool
+isPangram xs = all (`elem` fixedText) ['a'..'z']
+  where fixedText = map toLower xs

exercises/pangram/package.yaml

@@ -0,0 +1,19 @@
+name: pangram
+
+dependencies:
+  - base
+
+library:
+  exposed-modules: Pangram
+  source-dirs: src
+  dependencies:
+  # - foo       # List here the packages you
+  # - bar       # want to use in your solution.
+
+tests:
+  test:
+    main: Tests.hs
+    source-dirs: test
+    dependencies:
+      - pangram
+      - hspec

exercises/pangram/src/Pangram.hs

@@ -0,0 +1,4 @@
+module Pangram (isPangram) where
+
+isPangram :: String -> Bool
+isPangram text = error "You need to implement this function."

exercises/pangram/stack.yaml

@@ -0,0 +1 @@
+resolver: lts-8.2

exercises/pangram/test/Tests.hs

@@ -0,0 +1,65 @@
+{-# LANGUAGE RecordWildCards #-}
+
+import Data.Foldable     (for_)
+import Test.Hspec        (Spec, describe, it, shouldBe)
+import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
+
+import Pangram (isPangram)
+
+main :: IO ()
+main = hspecWith defaultConfig {configFastFail = True} specs
+
+specs :: Spec
+specs = describe "pangram" $
+          describe "isPangram" $ for_ cases test
+  where
+    test Case{..} = it description $ isPangram input `shouldBe` expected
+
+-- Adapted from
+-- Source: exercism/x-common/exercises/pangram/canonical-data.json
+-- Version: 1.0.0
+-- Date: 2017-03-28.
+
+data Case = Case { description :: String
+                 , input       :: String
+                 , expected    :: Bool
+                 }
+
+cases :: [Case]
+cases = [ Case { description = "sentence empty"
+               , input       = ""
+               , expected    = False
+               }
+        , Case { description = "pangram with only lower case"
+               , input       = "the quick brown fox jumps over the lazy dog"
+               , expected    = True
+               }
+        , Case { description = "missing character 'x'"
+               , input       = "a quick movement of the enemy will jeopardize five gunboats"
+               , expected    = False
+               }
+        , Case { description = "another missing character 'x'"
+               , input       = "the quick brown fish jumps over the lazy dog"
+               , expected    = False
+               }
+        , Case { description = "pangram with underscores"
+               , input       = "the_quick_brown_fox_jumps_over_the_lazy_dog"
+               , expected    = True
+               }
+        , Case { description = "pangram with numbers"
+               , input       = "the 1 quick brown fox jumps over the 2 lazy dogs"
+               , expected    = True
+               }
+        , Case { description = "missing letters replaced by numbers"
+               , input       = "7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog"
+               , expected    = False
+               }
+        , Case { description = "pangram with mixed case and punctuation"
+               , input       = "\"Five quacking Zephyrs jolt my wax bed.\""
+               , expected    = True
+               }
+        , Case { description = "upper and lower case versions of the same character should not be counted separately"
+               , input       = "the quick brown fox jumped over the lazy FOX"
+               , expected    = False
+               }
+        ]