Hi everyone, I would like to announce the initial release of event-lang, an experimental Racket library that simplifies the creation of complex synchronizable events.
https://pkgd.racket-lang.org/pkgn/package/event-lang Event-lang provides a primitive expression lifting form, > (pure 123) #<evt> some event combinators, > (sync (fmap + (pure 1) (pure 2))) 3 > (sync (app (pure +) (pure 1) (pure 2))) 3 > (sync (bind (pure 1) (pure 2) (λ xs (pure (apply + xs))))) 3 and a collection of event-friendly alternatives to base Racket forms and functions. > (sync (event-let ([x (pure 1)] [y (pure 2)]) (pure (list x y)))) '(1 2) Composite events make progress by synchronizing constituent events, either concurrently or in a predictable sequence. Synchronization results can be ordered as specified, > (let ([t0 (current-inexact-milliseconds)]) (define (now) (- (current-inexact-milliseconds) t0)) (sync (async-args (pure (cons 1 (now))) (pure (cons 2 (now))) (pure (cons 3 (now)))))) '(1 . 0.200927734375) '(2 . 0.14990234375) '(3 . 0.178955078125) or as completed. > (let ([t0 (current-inexact-milliseconds)]) (define (now) (- (current-inexact-milliseconds) t0)) (sync (async-set (pure (cons 1 (now))) (pure (cons 2 (now))) (pure (cons 3 (now)))))) '(2 . 0.0771484375) '(3 . 0.093017578125) '(1 . 0.123046875) The project has three outstanding objectives: 1. Provide a sophisticated lifting form to simplify usage of the provided constructs. The event/event module contains a first approximation. Its construction was tedious and error prone, so I commented out the docs. 2. Provide a full-blown #lang event/racket/base for producing whole modules of events and event constructors from ordinary Racket code in a principled manner. 3. Provide support for static analysis of synchronization behaviors. Event programming in Racket is a curious form of meta-programming, and a few simple compile-time checks could reduce cognitive overhead. This pre-release is a request for feedback in anticipation of a production-ready version 1.0. I would like to round out the base collection and devise a comprehensive testing plan, with a stretch goal of re-introducing the sophisticated lifting form. At the moment, I'm using event-lang daily and adding base constructs as needed. Feel free to do the same or request your favorites. Please take a look and let me know what you think. Eric -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
