Read a file with promises in TypeScript on Node

import * as fs from “fs”; import { promisify } from “util”; const content: Promise<string> = promisify(fs.readFile)(“path/to/the/file”, { encoding: “UTF-8” }) I am tired of looking that up over and over every time I want to read a file into a promise in Node using TypeScript, so here it is. Next time, bring me here, Google. The promisify call turns fs.readFile from a callback-based method to a promise-based one. promisify accepts …

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Every action has two results (Erlang edition)

Every action has two results: a set of side effects on the world, and the next version of ourselves. I learned this from Erlang, a purely functional yet stateful programming language. Erlang uses actor-based concurrency. The language is fully immutable, yet the programs are not: every time an actor receives a message, it can send …

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Provenance and causality in distributed systems

Can you take a piece of data in your system and say what version of code put it in there, based on what messages from other systems? and what information a human viewed before triggering an action? Me neither. Why is this acceptable? (because we’re used to it.)We could make this possible. We could trace …

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Talk: Concurrency Options on the JVM

or, “Everything You Never Wanted to Know About java.util.concurrent.ExecutorService But Needed To” from StrangeLoop, 18 Sep 2014 Abstract: A careful design lets you write a concurrent application without thinking about deadlock or synchronization. Getting to that design takes a lot of thinking. This session delivers the background you need to make good decisions about concurrency …

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Scala: the global ExecutionContext makes your life easier

TL;DR – when in doubt, stick with scala.concurrent.ExecutionContext.global When you want to run some asynchronous code, choosing a thread pool isn’t any fun. Scala has your back, with its global ExecutionContext. When I try to put some code in a Future without specifying where to run it, Scala tells me what to do: scala> Future(println(“Do something slow”)):14: …

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