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Fibers

Fibers are an abstraction over sequential computation, similar to threads but at a higher level. There are two ways to think about this model: by example, and abstractly from first principles. We'll start with the example.

(credit here is very much due to Fabio Labella, who's incredible Scala World talk describes these ideas far better than I can)

Callback Sequentialization

Consider the following three functions

import cats.syntax.apply._
import io.circe._
import io.circe.literal._
object JsonValidation{
def validate[A: Decoder]( f: HCursor => ACursor, pred: A => Boolean, err: A => String ): Decoder[A] =
Decoder.instance(
f andThen{ ac =>
ac.as[A].flatMap( a =>
if ( pred( a ) )
@SystemFw
SystemFw / Free conversation.md
Last active October 17, 2023 09:57
Explaining some of the mechanics of interpretation of Free programs

Balaji Sivaraman @balajisivaraman_twitter

Hi all, I need some help understanding a piece of Doobie code from the examples. It is the StreamingCopy one: (https://github.com/tpolecat/doobie/blob/series/0.4.x/yax/example/src/main/scala/example/StreamingCopy.scala). I am using a modified version of the fuseMap2 example from that file. Here’s how I’ve modified it for my requirements:

  def fuseMap[F[_]: Catchable: Monad, A, B](
      source: Process[ConnectionIO, A],
      sink: Vector[A] => ConnectionIO[B],
      delete: ConnectionIO[Unit]
  )(
 sourceXA: Transactor[F],

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x
@atoponce
atoponce / gist:07d8d4c833873be2f68c34f9afc5a78a
Last active May 14, 2024 00:59 — forked from tqbf/gist:be58d2d39690c3b366ad
Cryptographic Best Practices

Cryptographic Best Practices

Putting cryptographic primitives together is a lot like putting a jigsaw puzzle together, where all the pieces are cut exactly the same way, but there is only one correct solution. Thankfully, there are some projects out there that are working hard to make sure developers are getting it right.

The following advice comes from years of research from leading security researchers, developers, and cryptographers. This Gist was [forked from Thomas Ptacek's Gist][1] to be more readable. Additions have been added from

@curtismcmullan
curtismcmullan / setup_selenium.sh
Last active May 2, 2023 22:56
Setup Selenium Server on Ubuntu 14.04
#!/bin/bash
# Following the guide found at this page
# http://programmingarehard.com/2014/03/17/behat-and-selenium-in-vagrant.html
echo "\r\nUpdating system ...\r\n"
sudo apt-get update
# Create folder to place selenium in
@mojavelinux
mojavelinux / atom-fedora-20.adoc
Last active September 26, 2022 18:21
Instructions for building and launching the Atom text editor on Fedora 20.

Using Atom on Fedora 20

This guide walks you through the steps of building and launching the Atom text editor on Fedora 20.

Building Atom

  1. Install prerequisite packages

@willurd
willurd / web-servers.md
Last active May 17, 2024 16:24
Big list of http static server one-liners

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000