PROMISES
A “promise” is a surrogate entity that acts as a stand-in for a result that does not yet exist. The term “promise” was first proposed by Daniel Friedman and David Wise in their 1976 paper, The Impact of Applicative Programming on Multiprocessing, but the conceptual behavior of a promise would not be formalized until a decade later by Barbara Liskov and Liuba Shrira in their 1988 paper, Promises: Linguistic Support for Efficient Asynchronous Procedure Calls in Distributed Systems. Contemporary computer scientists described similar concepts such as an “eventual,” “future,” “delay,” or “deferred”; all of these described in one form or another a programming tool for synchronizing program execution.
The Promises/A+ Specification
Early forms of promises appeared in jQuery and Dojo's Deferred API, and in 2010, growing popularity led to the Promises/A specification inside the CommonJS project....
