boundary

scala.util.boundary

objectboundary

A boundary that can be exited bybreak calls.boundary andbreak represent a unified and superior alternative for thescala.util.control.NonLocalReturns andscala.util.control.Breaks APIs. The main differences are:

Unified names:boundary to establish a scope,break to leave it.break can optionally return a value.
Integration with exceptions.breaks are logically non-fatal exceptions. TheBreak exception class extendsRuntimeException and is optimized so that stack trace generation is suppressed.
Better performance: breaks to enclosing scopes in the same method can be rewritten to jumps.

Example usage:

import scala.util.boundary, boundary.breakdef firstIndex[T](xs: List[T], elem: T): Int = boundary:   for (x, i) <- xs.zipWithIndex do     if x == elem then break(i)   -1

Attributes

Source: boundary.scala
Graph
Supertypes: classObject
traitMatchable
classAny
Self type: boundary.type

Members list

Type members

Classlikes

finalclassBreak[T] extendsRuntimeException

User code should callbreak.apply instead of throwing this exception directly.

Attributes

Source: boundary.scala
Supertypes: classRuntimeException
classException
classThrowable
traitSerializable
classObject
traitMatchable
classAny
Show all

finalclassLabel[-T]

Labels are targets indicating which boundary will be exited by abreak.

Attributes

Source: boundary.scala
Supertypes: classObject
traitMatchable
classAny

Value members

Concrete methods

inlinedefapply[T](inlinebody:Label[T]?=>T):T

Runbody with freshly generated label as implicit argument. Catch any breaks associated with that label and return their results instead ofbody's result.