WhenAnyValue

WhenAnyValue is a concept that appears in some programming contexts, particularly within the realm of observable data streams or reactive programming. It refers to a mechanism that allows you to react to any change in the value of an observable, regardless of what the new value actually is. Instead of specifying a particular new value to trigger an action, you simply indicate that *any* change is sufficient.

This is useful in scenarios where the mere occurrence of an update is significant, rather than the specific data brought by that update. For instance, if you have a timer that ticks every second, you might want to update a "last updated" timestamp whenever the timer fires. You don't care about the specific number of seconds that have passed, only that the timer has indeed ticked.

In practical implementations, WhenAnyValue might be a method or operator provided by a reactive programming library. When invoked, it subscribes to an observable and executes a given action or callback function every time the observable emits a new value. The actual value emitted is often passed to the callback, but the core functionality of WhenAnyValue is its indifference to the specific nature of that value, focusing solely on its presence. This contrasts with operators that might trigger an action only when a value meets certain criteria or matches a specific pattern.