Merge pull request scala-exercises#43 from natansil/patch-1

add collection style operations to options

Author: Rafa Paradela

app/json/options.json

@@ -45,6 +45,24 @@
         "0.0"
       ],
       "postparagraph": ""
+    },
+    {
+      "preparagraph": "An alternative for pattern matching is performing collection style operations.\nThis is possible because an option could be looked at as a collection with either one or zero elements.\n\nOne of these operations is `map`. this operation allows to map the inner value to a different type while preserving the option",
+      "code": "val number: Option[Int] = Some(3)\nval noNumber: Option[Int] = None\nval result1 = number.map(_ * 1.5)\nval result2 = noNumber.map(_ * 1.5)\n\nresult1 should be(__)\nresult2 should be(__)",
+      "solutions": [
+        "Some(4.5)",
+        "None"
+      ],
+      "postparagraph": ""
+    },
+    {
+      "preparagraph": "Another operation is `fold`. this operation will extract the value from the option, or provide a default if the value is `None`",
+      "code": "val number: Option[Int] = Some(3)\nval noNumber: Option[Int] = None\nval result1 = number.fold(0)(_ * 3)val result2 = noNumber.fold(0)(_ * 3)\n\nresult1 should be(__)\nresult2 should be(__)",
+      "solutions": [
+        "9",
+        "0"
+      ],
+      "postparagraph": ""
     }
   ]
-}
+}