Introduction to Scala Part3: Option & Pattern Matching
Bubu
4,020 views
Open Source Your Knowledge, Become a Contributor
Technology knowledge has to be shared and made accessible for free. Join the movement.
Create your own Option type
- Some extends Option
- None is an object that extends Option
Goal of this exercice: create your own MyOption, MySome and MyNone. For the sake of simplicity, MyOption, MySome and MyNone will have simpler implementations
MySome
MyNone
Open Source Your Knowledge: become a Contributor and help others learn. Create New Content
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
package fp101.tp03.option
object ExerciceOptionCreator {
/**
*
* Our own simplified implementation of Option type
*
*
*/
trait MyOption[+T] {
def get: T
/**
*
* Method to implement here
*
* Note: U :> T says that B type parameter must be a supertype of T
* hint: implements the methods of MySome and MyNone before
*/
def getOrElse[U >: T](e: U): U = ???
def isEmpty: Boolean
}
class MySome[T](x: T) extends MyOption[T] {
def get: T = ???
def isEmpty: Boolean = ???
}
object MySome {
def apply[T](e: T): MySome[T] = ???
Enter to Rename, Shift+Enter to Preview