Packages

object PartialFunction

A few handy operations which leverage the extra bit of information available in partial functions. Examples:

import PartialFunction._

def strangeConditional(other: Any): Boolean = cond(other) {
  case x: String if x == "abc" || x == "def"  => true
  case x: Int => true
}
def onlyInt(v: Any): Option[Int] = condOpt(v) { case x: Int => x }
Source
PartialFunction.scala
Linear Supertypes
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. PartialFunction
  2. AnyRef
  3. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Type Members

  1. final class ElementWiseExtractor[-A, +B] extends AnyVal

Value Members

  1. def cond[T](x: T)(pf: PartialFunction[T, Boolean]): Boolean

    Creates a Boolean test based on a value and a partial function.

    Creates a Boolean test based on a value and a partial function. It behaves like a 'match' statement with an implied 'case _ => false' following the supplied cases.

    x

    the value to test

    pf

    the partial function

    returns

    true, iff x is in the domain of pf and pf(x) == true.

  2. def condOpt[T, U](x: T)(pf: PartialFunction[T, U]): Option[U]

    Transforms a PartialFunction[T, U] pf into Function1[T, Option[U]] f whose result is Some(x) if the argument is in pf's domain and None otherwise, and applies it to the value x.

    Transforms a PartialFunction[T, U] pf into Function1[T, Option[U]] f whose result is Some(x) if the argument is in pf's domain and None otherwise, and applies it to the value x. In effect, it is a match statement which wraps all case results in Some(_) and adds case _ => None to the end.

    x

    the value to test

    pf

    the PartialFunction[T, U]

    returns

    Some(pf(x)) if pf isDefinedAt x, None otherwise.

  3. def empty[A, B]: PartialFunction[A, B]

    The partial function with empty domain.

    The partial function with empty domain. Any attempt to invoke empty partial function leads to throwing scala.MatchError exception.

  4. def fromFunction[A, B](f: (A) => B): PartialFunction[A, B]

    Converts an ordinary function to a partial function.

    Converts an ordinary function to a partial function. Note that calling isDefinedAt(x) on this partial function will return true for every x.

    f

    an ordinary function

    returns

    a partial function which delegates to the ordinary function f