fulfill ( value promise: promise -- )
Promises

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Vocabulary
concurrency.promises

Inputs

value	an object
promise	a promise

Outputs
None

Word description
Fulfills a promise by writing a value to it. Any threads waiting for the value are notified.

Errors
Throws an error if the promise has already been fulfilled.

Definition

USING: accessors boxes concurrency.conditions kernel threads
typed ;

IN: concurrency.promises

TYPED: fulfill ( value promise: promise -- )
    [ box>> ] keep over occupied>>
    [ promise-already-fulfilled ]
    [ [ >box ] [ threads>> notify-all ] bi* yield ] if ;