Demonstrate returning values from functions

Unit 1/Lesson 4/returningFunctions.hs

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+sfOffice :: ([Char], [Char]) -> [Char]
+sfOffice name = if surname < "L"
+                then nameText ++ " - PO Box 1234 - San Francisco, CA, 94111"
+                else nameText ++ " - PO Box 1010 - San Francisco, CA, 94109"
+  where surname = snd name
+        nameText = fst name ++ " " ++ surname
+
+
+nyOffice :: ([Char], [Char]) -> [Char]
+nyOffice name = nameText ++ ": PO Box 789 - New York, NY, 10013"
+  where nameText = fst name ++ " " ++ snd name
+
+
+renoOffice :: (a, [Char]) -> [Char]
+renoOffice name = nameText ++ " - PO Box 456 - Reno, NV 89523"
+  where nameText = snd name
+
+
+getLocation :: [Char] -> ([Char], [Char]) -> [Char]
+getLocation location = case location of
+  "ny" -> nyOffice
+  "sf" -> sfOffice
+  "reno" -> renoOffice
+  _ -> (\name -> fst name ++ " " ++ snd name)
+
+
+addressLetter :: ([Char], [Char]) -> [Char] -> [Char]
+addressLetter name location = locationFunction name
+  where locationFunction = getLocation location