org.scalactic

OptionSugar

trait OptionSugar extends AnyRef

Trait providing an implicit class that adds a toOr method to Option, which converts Some to Good, None to Bad.

You can use the toOr method to record information about why a processing of nested Options resulted in None. For example, the following for expression results in None if either the passed optional Person is None or else if the contained optional age is None:

scala> case class Person(name: String, age: Option[Int])
defined class Person

scala> def ageOf(person: Option[Person]) =
     |   for {
     |     per <- person
     |     age <- per.age
     |   } yield age
ageOf: (person: Option[Person])Option[Int]

scala> ageOf(Some(Person("Ralph", Some(32))))
res0: Option[Int] = Some(32)

scala> ageOf(Some(Person("Curt", None)))
res3: Option[Int] = None

scala> ageOf(None)
res2: Option[Int] = None

If you instead populate the for expression with Ors, supplying an error message or other "bad" value to the toOr method in case of None, you'll get an indication of which part failed if a None is encountered:

scala> import OptionSugar._
import OptionSugar._

scala> def ageOf(person: Option[Person]) =
     |   for {
     |     per <- person toOr "no person here"
     |     age <- per.age toOr "ageless person"
     |   } yield age
ageOf: (person: Option[Person])org.scalactic.Or[Int,String]

scala> ageOf(Some(Person("Ralph", Some(32))))
res1: org.scalactic.Or[Int,String] = Good(32)

scala> ageOf(Some(Person("Curt", None)))
res2: org.scalactic.Or[Int,String] = Bad(ageless person)

scala> ageOf(None)
res3: org.scalactic.Or[Int,String] = Bad(no person here)

Source
OptionSugar.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. OptionSugar
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Type Members

  1. implicit class Optionizer[G] extends AnyRef

    Implicit class that adds a toOr method to Option, which converts Some to Good, None to Bad.

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any
  6. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  7. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  8. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  9. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  10. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  11. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  12. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  13. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  14. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  15. final def notify(): Unit

    Definition Classes
    AnyRef
  16. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  17. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  18. def toString(): String

    Definition Classes
    AnyRef → Any
  19. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  20. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  21. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped