Scala 3/scala/scala.util/DynamicVariable

DynamicVariable

scala.util.DynamicVariable

class DynamicVariable[T](init: T)

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.

Attributes

Source: DynamicVariable.scala
Graph
Supertypes: class Object

trait Matchable

class Any

Members list

Value members

Concrete methods

Returns a string representation of the object.

The default representation is platform dependent.

Attributes

Returns: a string representation of the object.
Definition Classes: Any
Source: DynamicVariable.scala

Retrieve the current value

Attributes

Source: DynamicVariable.scala

Change the currently bound value, discarding the old value.

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

Attributes

Source: DynamicVariable.scala

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

Value parameters

newval: The value to which to set the variable
thunk: The code to evaluate under the new setting

Attributes

Source: DynamicVariable.scala

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