Assertion: future's value | /r/HasProperty | needed
Facets:
value: as in call by need
type: OTHER
Source sentences:
text: This computation can start either eagerly when the future is created, or lazily when its value is first needed.
text: The computation can start as soon as the future is created (eager evaluation) or only when the value is actually needed (lazy evaluation), and may be suspended part-way through, or executed in one run.
text: A lazy future is a future that deterministically has lazy evaluation semantics: the computation of the future's value starts when the value is first needed, as in call by need.
text: To implement implicit lazy thread-specific futures (as provided by Alice ML, for example) in terms in non-thread-specific futures, needs a mechanism to determine when the future's value is first needed (for example, the WaitNeeded construct in Oz).
text: If all values are objects, then the ability to implement transparent forwarding objects is sufficient, since the first message sent to the forwarder indicates that the future's value is needed.