Add Result.recover

Similar to getOrElse but returns an Ok of the transformed error

src/main/kotlin/com/github/michaelbull/result/Or.kt

@@ -29,3 +29,14 @@ inline infix fun <V, E> Result<V, E>.orElse(transform: (E) -> Result<V, E>): Res
         is Err -> transform(error)
     }
 }
+
+/**
+ * Returns the [transformation][transform] of the [error][Err.error] if this [Result] is [Err],
+ * otherwise this [Ok].
+ */
+inline infix fun <V, E> Result<V, E>.recover(transform: (E) -> V): Ok<V> {
+    return when(this) {
+        is Ok -> this
+        is Err -> Ok(transform(error))
+    }
+}

src/test/kotlin/com/github/michaelbull/result/OrTest.kt

@@ -41,4 +41,22 @@ internal class OrTest {
             )
         }
     }
+
+    internal class `recover` {
+        @Test
+        internal fun returnsValueIfOk() {
+            assertEquals(
+                expected = 3000,
+                actual = Ok(3000).recover { 4000 }.get()
+            )
+        }
+
+        @Test
+        internal fun returnsTransformedValueIfErr() {
+            assertEquals(
+                expected = 2000,
+                actual = Err(4000).recover { 2000 }.get()
+            )
+        }
+    }
 }