DynamicVariable
Related Doc:
package util
Retrieve the current value
Change the currently bound value, discarding the old value.
Change the currently bound value, discarding the old value. Usually withValue() gives better semantics.
Set the value of the variable while executing the specified thunk.
Set the value of the variable while executing the specified thunk.
The value to which to set the variable
The code to evaluate under the new setting
DynamicVariablesprovide 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
withValuemethod. Values pushed viawithValueonly stay valid while thewithValue'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
DynamicVariablegets 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.1.1, 2007-5-21