From 84759bd46e7e50571ff523698e25d0d320e641a5 Mon Sep 17 00:00:00 2001
From: Luke Westby <luke.westby@raise.com>
Date: Sat, 9 Apr 2016 20:15:51 -0700
Subject: [PATCH] refactor sublist

---
 exercises/sublist/Sublist.elm      |  7 ++++++
 exercises/sublist/Sublist.example  | 25 ++++++++++----------
 exercises/sublist/SublistTests.elm | 38 +++++++++++++++---------------
 3 files changed, 38 insertions(+), 32 deletions(-)

diff --git a/exercises/sublist/Sublist.elm b/exercises/sublist/Sublist.elm
index 53ce299..a536680 100644
--- a/exercises/sublist/Sublist.elm
+++ b/exercises/sublist/Sublist.elm
@@ -1 +1,8 @@
 module Sublist (..) where
+
+
+type ListComparison
+  = Equal
+  | Superlist
+  | Sublist
+  | Unequal
diff --git a/exercises/sublist/Sublist.example b/exercises/sublist/Sublist.example
index 8cea41b..1f2a36f 100644
--- a/exercises/sublist/Sublist.example
+++ b/exercises/sublist/Sublist.example
@@ -1,31 +1,30 @@
 module Sublist (..) where
 
-import List exposing (..)
-import String
+
+type ListComparison
+  = Equal
+  | Superlist
+  | Sublist
+  | Unequal
 
 
-sublist : List a -> List a -> String
+sublist : List a -> List a -> ListComparison
 sublist alist blist =
   if alist == blist then
-    "Equal"
+    Equal
   else if inList alist blist then
-    "Superlist"
+    Superlist
   else if inList blist alist then
-    "Sublist"
+    Sublist
   else
-    "Unequal"
+    Unequal
 
 
 inList : List a -> List a -> Bool
 inList alist blist =
   let
     getLastInList sublist =
-      case (List.tail sublist) of
-        Just list ->
-          list
-
-        Nothing ->
-          []
+      Maybe.withDefault [] (List.tail sublist)
   in
     if (List.length alist) < (List.length blist) then
       False
diff --git a/exercises/sublist/SublistTests.elm b/exercises/sublist/SublistTests.elm
index aba6f6b..0f89598 100644
--- a/exercises/sublist/SublistTests.elm
+++ b/exercises/sublist/SublistTests.elm
@@ -3,7 +3,7 @@ module Main (..) where
 import Task
 import Console
 import ElmTest exposing (..)
-import Sublist exposing (sublist)
+import Sublist exposing (sublist, ListComparison(..))
 
 
 tests : Test
@@ -12,58 +12,58 @@ tests =
     "Sublist"
     [ test
         "empty equals empty"
-        (assertEqual "Equal" (sublist [] []))
+        (assertEqual Equal (sublist [] []))
     , test
         "empty is a sublist of anything"
-        (assertEqual "Sublist" (sublist [] [ 1, 2 ]))
+        (assertEqual Sublist (sublist [] [ 1, 2 ]))
     , test
         "anything is a superlist of empty"
-        (assertEqual "Superlist" (sublist [ 1, 2 ] []))
+        (assertEqual Superlist (sublist [ 1, 2 ] []))
     , test
         "1 is not 2"
-        (assertEqual "Unequal" (sublist [ 1 ] [ 2 ]))
+        (assertEqual Unequal (sublist [ 1 ] [ 2 ]))
     , test
         "compare larger equal lists"
-        (assertEqual "Equal" (sublist [ 1, 1, 1 ] [ 1, 1, 1 ]))
+        (assertEqual Equal (sublist [ 1, 1, 1 ] [ 1, 1, 1 ]))
     , test
         "sublist at start"
-        (assertEqual "Sublist" (sublist [ 1, 2, 3 ] [ 1, 2, 3, 4, 5 ]))
+        (assertEqual Sublist (sublist [ 1, 2, 3 ] [ 1, 2, 3, 4, 5 ]))
     , test
         "sublist in the middle"
-        (assertEqual "Sublist" (sublist [ 4, 3, 2 ] [ 5, 4, 3, 2, 1 ]))
+        (assertEqual Sublist (sublist [ 4, 3, 2 ] [ 5, 4, 3, 2, 1 ]))
     , test
         "sublist at end"
-        (assertEqual "Sublist" (sublist [ 3, 4, 5 ] [ 1, 2, 3, 4, 5 ]))
+        (assertEqual Sublist (sublist [ 3, 4, 5 ] [ 1, 2, 3, 4, 5 ]))
     , test
         "partially matching sublist at start"
-        (assertEqual "Sublist" (sublist [ 1, 1, 2 ] [ 1, 1, 1, 2 ]))
+        (assertEqual Sublist (sublist [ 1, 1, 2 ] [ 1, 1, 1, 2 ]))
     , test
         "sublist early in huge list"
-        (assertEqual "Sublist" (sublist [ 3, 4, 5 ] [1..100000]))
+        (assertEqual Sublist (sublist [ 3, 4, 5 ] [1..100000]))
     , test
         "huge sublist not in list"
-        (assertEqual "Unequal" (sublist [10..100001] [1..100000]))
+        (assertEqual Unequal (sublist [10..100001] [1..100000]))
     , test
         "superlist at start"
-        (assertEqual "Superlist" (sublist [ 1, 2, 3, 4, 5 ] [ 1, 2, 3 ]))
+        (assertEqual Superlist (sublist [ 1, 2, 3, 4, 5 ] [ 1, 2, 3 ]))
     , test
         "superlist in middle"
-        (assertEqual "Superlist" (sublist [ 5, 4, 3, 2, 1 ] [ 4, 3, 2 ]))
+        (assertEqual Superlist (sublist [ 5, 4, 3, 2, 1 ] [ 4, 3, 2 ]))
     , test
         "superlist at end"
-        (assertEqual "Superlist" (sublist [ 1, 2, 3, 4, 5 ] [ 3, 4, 5 ]))
+        (assertEqual Superlist (sublist [ 1, 2, 3, 4, 5 ] [ 3, 4, 5 ]))
     , test
         "partially matching superlist at start"
-        (assertEqual "Superlist" (sublist [ 1, 1, 1, 2 ] [ 1, 1, 2 ]))
+        (assertEqual Superlist (sublist [ 1, 1, 1, 2 ] [ 1, 1, 2 ]))
     , test
         "superlist early in huge list"
-        (assertEqual "Superlist" (sublist [1..100000] [ 3, 4, 5 ]))
+        (assertEqual Superlist (sublist [1..100000] [ 3, 4, 5 ]))
     , test
         "recurring values sublist"
-        (assertEqual "Sublist" (sublist [ 1, 2, 1, 2, 3 ] [ 1, 2, 3, 1, 2, 1, 2, 3, 2, 1 ]))
+        (assertEqual Sublist (sublist [ 1, 2, 1, 2, 3 ] [ 1, 2, 3, 1, 2, 1, 2, 3, 2, 1 ]))
     , test
         "recurring values unequal"
-        (assertEqual "Unequal" (sublist [ 1, 2, 1, 2, 3 ] [ 1, 2, 3, 1, 2, 3, 2, 3, 2, 1 ]))
+        (assertEqual Unequal (sublist [ 1, 2, 1, 2, 3 ] [ 1, 2, 3, 1, 2, 3, 2, 3, 2, 1 ]))
     ]