Demonstrate use of First Class Functions

Unit 1/Lesson 4/firstClassFunctions.hs

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+inc :: Num a => a -> a
+inc n = n + 1
+double :: Num a => a -> a
+double n = n * 2
+square :: Num a => a -> a
+square n = n ^ 2
+
+isEven :: Integral p => (p -> p) -> p -> p
+isEven myFunction x = if even x
+                      then myFunction x
+                      else x
+
+
+ifEvenDouble :: Integral p => p -> p
+ifEvenDouble x = isEven double x
+ifEvenInc :: Integral p => p -> p
+ifEvenInc x = isEven inc x
+ifEvenSquare :: Integral p => p -> p
+ifEvenSquare x = isEven square x