PartialFunction

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

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 }

Companion: class

class Object

trait Matchable

class Any

Type members

Classlikes

Value members

Concrete methods

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.

Value Params

pf: the partial function
x: the value to test

Returns

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

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.

Value Params

pf: the PartialFunction[T, U]
x: the value to test

Returns

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

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.

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.

Value Params

f: an ordinary function

Returns

a partial function which delegates to the ordinary function f