Spatio-Temporal Domains: An Overview

Lecture Notes in Computer Science

2020

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Asynchronous concurrent programing is a widely spread technique offering some simple concurrent primitives that are restricted in such a way that the resulting concurrent programs are deadlock free. In this paper, we develop, study and extend a formal model of the underlying application programmer interface. For such a purpose, we formally define the extension of a monad by some notion of monad references uniquely bound to running monad actions together with the associated asynchronous primitives fork and read. The expected semantics is specified via two series of equations relating the behavior of these extension primitives with the underlying monad primitives. Thanks to these equations, we recover a fairly general notion of promises and prove that they induce a monad isomorphic to the underlying monad. We also show how synchronous and asynchronous reactive data flow programming eventually derive from such a formalization of asynchronous concurrency, uniformly lifting fork and read primitives from monadic actions to monadic streams of actions. Our proposal is illustrated throughout by concrete extensions of Haskell IO monad that allows for proving the soundness of the proposed equations and the applicability of the resulting API.

Section: Related Work and Conclusionmentioning

confidence: 97%

Section: Preliminaries On Monadic Functors and Monad Actionsmentioning

confidence: 99%

An Equational Modeling of Asynchronous Concurrent Programming

Lecture Notes in Computer Science

2020

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“…for every action m ::t a and function f ::a → b. In other words, in a timed setting, functors preserve specified durations, time measurement acting over types as a fibration [10].…”

Section: Timed Monad Lawsmentioning

confidence: 99%

A Timed IO Monad

Practical Aspects of Declarative Languages

2020

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Programming with explicit timing information is often tedious and error prone. This is especially visible in music programming where, when played, the specified durations of notes and rests must be shortened in order to compensate the actual duration of all surrounding processing. In this paper, we develop the notion of timed extension of a monad that aims at relieving programmers from such a burden. We show how, under simple conditions, such extensions can be built, and how useful features of monad programming such as asynchronous concurrency with promises or data-flow programming with monadic streams can be uniformly lifted to the resulting timed programming framework. Even though presented and developed in the abstract, the notion of timed extension of a monad is nevertheless illustrated by two concrete instances: a default timed IO monad where programmers specify durations in microseconds, and a musically timed IO monad, where programmers specify durations in number of beats, the underlying tempo, that is, the speed of the music in beats per minute, possibly changed whenever needed.

“…There are various ways to define synchronous functions, as for instance done the Synchronous language family [1,21] or as detailed by the author when developing the notion of timed domains [9].…”

Section: Synchronous Stream Functionsmentioning

confidence: 99%

Screaming in the IO monad: a realtime audio processing and control experiment in Haskell

Proceedings of the 7th ACM SIGPLAN International Workshop on Functional Art, Music, Modeling, and Design

2019

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We investigate in this paper the applicability of the notion monad streams to media stream programming, and, more specifically, audio processing and control. Simply said, a monad stream is sort of a list guarded by a monad action that returns either nothing when the stream is over, or, otherwise, just the current value of the stream and the guarding action of its continuation.Applied to the IO monad, it appears that monad streams can be used for modeling both input streams and output streams, with full control of the possibly synchronism between input and output streams in stream functions. This allows for defining both synchronous or asynchronous functions, or any combination of both notions.In the abstract, this opens quite intriguing and generic solutions towards programming systems that are globally asynchronous and locally synchronous (GALS). In the concrete, applied to real-time audio, this allows for combining, in a fairly simple and unified way, both (synchronous) audio processing and (asynchronous) audio control.As far as performance are concerned, our proposal allows non-trivial transformation of audio streams at 44100 Hz with a 10 ms latency, a performance comparable to functional programing languages dedicated to real-time audio processing such as Faust.