Function1

@implicitNotFound(msg = "No implicit view available from ${T1} => ${R}.")

trait Function1[@specialized -T1, @specialized +R] extends AnyRef

A function of 1 parameter.

In the following example, the definition of succ is a shorthand for the anonymous class definition anonfun1:

object Main extends App {
  val succ = (x: Int) => x + 1
  val anonfun1 = new Function1[Int, Int] {
    def apply(x: Int): Int = x + 1
  }
  assert(succ(0) == anonfun1(0))
}

Note that the difference between Function1 and scala.PartialFunction is that the latter can specify inputs which it will not handle.

Companion:: object
Source:: Function1.scala

class Object

trait Matchable

class Any

class From <:< To

class From =:= To

class Conversion[T, U]

trait PartialFunction[A, B]

trait MapOps[K, V, CC, C]

trait Map[K, V]

class AbstractMap[K, V]

class HashMap[K, V]

class IntMap[T]

class ListMap[K, V]

class LongMap[T]

class Map1[K, V]

class Map2[K, V]

class Map3[K, V]

class Map4[K, V]

class WithDefault[K, V]

class TreeMap[K, V]

class TreeSeqMap[K, V]

class VectorMap[K, V]

class AbstractMap[K, V]

class TrieMap[K, V]

class AnyRefMap[K, V]

class CollisionProofHashMap[K, V]

class HashMap[K, V]

class LinkedHashMap[K, V]

class ListMap[K, V]

class LongMap[V]

class WithDefault[K, V]

class OpenHashMap[Key, Value]

class TreeMap[K, V]

class SystemProperties

trait DefaultMap[K, V]

trait SeqMap[K, V]

trait SortedMap[K, V]

trait Map[K, V]

trait MultiMap[K, V]

trait MapFactoryDefaults[K, V, CC, WithFilterCC]

class WeakHashMap[K, V]

trait MapView[K, V]

class AbstractMapView[K, V]

class Filter[K, V]

class FilterKeys[K, V]

class Id[K, V]

class MapValues[K, V, W]

class TapEach[K, V, U]

trait SortedMapFactoryDefaults[K, V, CC, WithFilterCC, UnsortedCC]

trait SortedMapOps[K, V, CC, C]

trait StrictOptimizedSortedMapOps[K, V, CC, C]

trait SortedMapOps[K, V, CC, C]

trait StrictOptimizedMapOps[K, V, CC, C]

trait MapOps[K, V, CC, C]

trait Seq[A]

class AbstractSeq[A]

class ArraySeq[A]

class ofBoolean

class ofByte

class ofChar

class ofDouble

class ofFloat

class ofInt

class ofLong

class ofRef[T]

class ofShort

class ofUnit

class LazyList[A]

class List[A]

class ::[A]

object Nil.type

class NumericRange[T]

class Exclusive[T]

class Inclusive[T]

class Queue[A]

class Range

class Exclusive

class Inclusive

class Stream[A]

class Cons[A]

object Empty.type

class Vector[A]

class WrappedString

class AbstractSeq[A]

class AbstractBuffer[A]

class ArrayBuffer[A]

class ArrayDeque[A]

class Queue[A]

class Stack[A]

class ListBuffer[A]

class UnrolledBuffer[T]

class ArraySeq[T]

class ofBoolean

class ofByte

class ofChar

class ofDouble

class ofFloat

class ofInt

class ofLong

class ofRef[T]

class ofShort

class ofUnit

class StringBuilder

trait IndexedSeq[A]

trait IndexedSeq[T]

trait IndexedBuffer[A]

trait LinearSeq[A]

trait Seq[A]

trait Buffer[A]

class Accumulator[A, CC, C]

class AnyAccumulator[A]

class DoubleAccumulator

class IntAccumulator

class LongAccumulator

class AbstractPartialFunction[T1, R]

trait SetOps[A, CC, C]

trait Set[A]

class AbstractSet[A]

class ValueSet

class ImmutableKeySet

class BitSet

class BitSet1

class BitSet2

class BitSetN

class HashSet[A]

class ListSet[A]

class Set1[A]

class Set2[A]

class Set3[A]

class Set4[A]

class ImmutableKeySortedSet

class TreeSet[A]

class AbstractSet[A]

class BitSet

class HashSet[A]

class LinkedHashSet[A]

class TreeSet[A]

trait SortedSet[A]

trait BitSet

trait SortedSet[A]

trait Set[A]

trait SortedSetOps[A, CC, C]

trait BitSetOps[C]

trait SortedSetFactoryDefaults[A, CC, WithFilterCC]

trait StrictOptimizedSortedSetOps[A, CC, C]

trait SortedSetOps[A, CC, C]

trait StrictOptimizedSetOps[A, CC, C]

trait SetOps[A, CC, C]

class FromJavaConsumer[T]

class FromJavaDoubleConsumer

class FromJavaDoubleFunction[R]

class FromJavaDoublePredicate

class FromJavaDoubleToIntFunction

class FromJavaDoubleToLongFunction

class FromJavaDoubleUnaryOperator

class FromJavaFunction[T, R]

class FromJavaIntConsumer

class FromJavaIntFunction[R]

class FromJavaIntPredicate

class FromJavaIntToDoubleFunction

class FromJavaIntToLongFunction

class FromJavaIntUnaryOperator

class FromJavaLongConsumer

class FromJavaLongFunction[R]

class FromJavaLongPredicate

class FromJavaLongToDoubleFunction

class FromJavaLongToIntFunction

class FromJavaLongUnaryOperator

class FromJavaPredicate[T]

class FromJavaToDoubleFunction[T]

class FromJavaToIntFunction[T]

class FromJavaToLongFunction[T]

class FromJavaUnaryOperator[T]

class AbstractFunction1[T1, R]

trait JFunction1$mcDD$sp

trait JFunction1$mcDF$sp

trait JFunction1$mcDI$sp

trait JFunction1$mcDJ$sp

trait JFunction1$mcFD$sp

trait JFunction1$mcFF$sp

trait JFunction1$mcFI$sp

trait JFunction1$mcFJ$sp

trait JFunction1$mcID$sp

trait JFunction1$mcIF$sp

trait JFunction1$mcII$sp

trait JFunction1$mcIJ$sp

trait JFunction1$mcJD$sp

trait JFunction1$mcJF$sp

trait JFunction1$mcJI$sp

trait JFunction1$mcJJ$sp

trait JFunction1$mcVD$sp

trait JFunction1$mcVF$sp

trait JFunction1$mcVI$sp

trait JFunction1$mcVJ$sp

trait JFunction1$mcZD$sp

trait JFunction1$mcZF$sp

trait JFunction1$mcZI$sp

trait JFunction1$mcZJ$sp

T1 => R

Value members

Abstract methods

Apply the body of this function to the argument.

Returns:: the result of function application.
Source:: Function1.scala

Concrete methods

@unspecialized

Composes two instances of Function1 in a new Function1, with this function applied first.

Type parameters:

A: the result type of function g

Value parameters:

g: a function R => A

Returns:

a new function f such that f(x) == g(apply(x))

Source:

Function1.scala

@unspecialized

Composes two instances of Function1 in a new Function1, with this function applied last.

Type parameters:

A: the type to which function g can be applied

Value parameters:

g: a function A => T1

Returns:

a new function f such that f(x) == apply(g(x))

Source:

Function1.scala

Definition Classes: Any
Source:: Function1.scala

Implicitly added by UnliftOps

Converts an optional function to a partial function.

Example:

Unlike Function.unlift, this UnliftOps.unlift method can be used in extractors.

val of: Int => Option[String] = { i =>
  if (i == 2) {
    Some("matched by an optional function")
  } else {
    None
  }
}
util.Random.nextInt(4) match {
  case of.unlift(m) => // Convert an optional function to a pattern
    println(m)
  case _ =>
    println("Not matched")
}

Source:

Function1.scala