Packages

c

scala.util

DynamicVariable

class DynamicVariable[T] extends AnyRef

DynamicVariables provide a binding mechanism where the current value is found through dynamic scope, but where access to the variable itself is resolved through static scope.

The current value can be retrieved with the value method. New values should be pushed using the withValue method. Values pushed via withValue only stay valid while the withValue's second argument, a parameterless closure, executes. When the second argument finishes, the variable reverts to the previous value.

someDynamicVariable.withValue(newValue) {
  // ... code called in here that calls value ...
  // ... will be given back the newValue ...
}

Each thread gets its own stack of bindings. When a new thread is created, the DynamicVariable gets a copy of the stack of bindings from the parent thread, and from then on the bindings for the new thread are independent of those for the original thread.

Source
DynamicVariable.scala
Linear Supertypes
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Inherited
  1. DynamicVariable
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new DynamicVariable(init: T)

Value Members

  1. def toString(): String

    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    DynamicVariable → AnyRef → Any
  2. def value: T

    Retrieve the current value

  3. def value_=(newval: T): Unit

    Change the currently bound value, discarding the old value.

    Change the currently bound value, discarding the old value. Usually withValue() gives better semantics.

  4. def withValue[S](newval: T)(thunk: => S): S

    Set the value of the variable while executing the specified thunk.

    Set the value of the variable while executing the specified thunk.

    newval

    The value to which to set the variable

    thunk

    The code to evaluate under the new setting