parsonsmatt

Someone asked whether or not acid-state was production ready. I shared my experiences:

parsonsmatt [11:32 AM] @nikolap it's used by cardano-wallet and Hackage. Based on my experience with acid-state, I'd say it is not a good choice for production data storage. For local desktop apps, SQLite is a much better choice, and for real production apps, Postgresql is king.

parsonsmatt [11:44 AM] acid-state did not have a test suite, at all, until I implemented the very first tests (for TemplateHaskell code generation) earlier this year. It has picked up some tests since then, but I'm still not confident in it's correctness.

It claims to be resilient to unplugging the power cord, but I doubt that, as it's not resilient to Ctrl-C: acid-state/acid-state#79

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

hobwekiva

import cats.Applicative
import cats.instances.list._
import cats.instances.option._
import cats.syntax.functor._
import cats.Id

trait Instance[TC[_]] {
  type Type
  def value: Type
  def typeclass: TC[Type]

puffnfresh

#!/bin/sh

## Or use an AUR helper, e.g.
## sudo aura -A nix
sudo pacman -S base-devel git
git clone https://aur.archlinux.org/nix.git
cd nix
makepkg -s
sudo pacman -U nix-*.pkg.tar.xz

jdegoes

-- A sequential series of parallel program fragments in `f`:
type SeqPar f a = Free (FreeAp f) a

liftFA :: forall f a. f a -> SeqPar f a
liftFA = pure >>> pure

liftSeq :: forall f a. Free f a -> SeqPar f a
liftSeq fa = foldFree fa liftFA

liftPar :: forall f a. FreeAp f a -> SeqPar f a

jdegoes

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

aaronlevin

{-# LANGUAGE DataKinds              #-}
{-# LANGUAGE FlexibleContexts       #-}
{-# LANGUAGE FlexibleInstances      #-}
{-# LANGUAGE GADTs                  #-}
{-# LANGUAGE KindSignatures         #-}
{-# LANGUAGE MultiParamTypeClasses  #-}
{-# LANGUAGE PolyKinds              #-}
{-# LANGUAGE RankNTypes             #-}
{-# LANGUAGE TypeOperators          #-}

ocharles

{-# LANGUAGE GeneralizedNewtypeDeriving #-}

import Control.Monad.IO.Class
import Control.Monad.Trans.Class
import Prelude hiding (log)

--------------------------------------------------------------------------------
-- The API for cloud files.
class Monad m => MonadCloud m where
  saveFile :: Path -> Bytes -> m ()

runarorama

import scalaz._, Scalaz._

// Adjunction between `F` and `G` means there is an
// isomorphism between `A => G[B]` and `F[A] => B`.
trait Adjunction[F[_],G[_]] {
  def leftAdjunct[A, B](a: A)(f: F[A] => B): G[B]
  def rightAdjunct[A, B](a: F[A])(f: A => G[B]): B
}

// Adjunction between free and forgetful functor.

kennwhite

Most VPN Services are Terrible

Short version: I strongly do not recommend using any of these providers. You are, of course, free to use whatever you like. My TL;DR advice: Roll your own and use Algo or Streisand. For messaging & voice, use Signal. For increased anonymity, use Tor for desktop (though recognize that doing so may actually put you at greater risk), and Onion Browser for mobile.

This mini-rant came on the heels of an interesting twitter discussion: https://twitter.com/kennwhite/status/591074055018582016