In functional programming, continuation-passing style (CPS) is a style of programming in which control is passed explicitly in the form of a continuation. Gerald Jay Sussman and Guy L. Steele, Jr. coined the phrase in AI Memo 349 (1975), which sets out the first version of the Scheme programming language. John C. Reynolds gives a detailed account of the numerous discoveries of continuations. A function written in continuation-passing style takes an extra argument: an explicit "continuation" i.e. a function of one argument. When the CPS function has computed its result value, it "returns" it by...

In computer science, future, promise, and delay refer to constructs used for synchronization in some concurrent programming languages. They describe an object that acts as a proxy for a result that is initially unknown, usually because the computation of its value is yet incomplete. The term promise was proposed in 1976 by Daniel P. Friedman and David Wise, and Peter Hibbard called it eventual. A somewhat similar concept future was introduced in 1977 in a paper by Henry Baker and Carl Hewitt. The terms future, promise, and delay are often used interchangeably, although some differences in usage...

In computer science, the event loop, message dispatcher, message loop, message pump, or run loop is a programming construct that waits for and dispatches events or messages in a program. It works by making a request to some internal or external "event provider" (which generally blocks the request until an event has arrived), and then it calls the relevant event handler ("dispatches the event"). The event-loop may be used in conjunction with a reactor, if the event provider follows the file interface, which can be selected or 'polled' (the Unix system call, not actual polling). The event loop almost...