smarter

Generalized Algebraic Data Types in Scala

Basic GADTs

Here's an ADT which is not a GADT, in Haskell:

data Expr = IntExpr Int | BoolExpr Bool

parsonsmatt

{-# LANGUAGE Rank2Types #-}
{-# LANGUAGE FlexibleContexts #-}

module Mtl where

import Control.Monad.State
import Control.Monad.Except

runMtl
    :: Bool

DaniSancas

Neo4j Tutorial

Fundamentals

Store any kind of data using the following graph concepts:

• Node: Graph data records
• Relationship: Connect nodes (has direction and a type)
• Property: Stores data in key-value pair in nodes and relationships
• Label: Groups nodes and relationships (optional)

slorber

////////////////////////////////////////////////////////////////////////
// Intro
///////////////////////

// Tools like Redux-saga, React-redux and Reselect can easily be used without Redux
// For Reselet there's nothing to do, it's just not coupled to Redux
// For the others, you just need to provide an adapter

// At Stample.co we use a legacy framework that is quite close to Redux but with a bad API
// We want to progressively migrate to Redux, so starting now to use Redux tools on new features will make our migration faster

mgmeier

{-# LANGUAGE BangPatterns #-}

{-
    Scenario / preconditions for the usefulness of this ring buffer:

    - mutable data structure
    - elements of the same size (here: ByteString, extending to values of class Storable should be trivial)
    - each element is denoted by a continuous Int id

    - main benefit, esp. for a large number of elements:

pathikrit

/**
 * Solves the n-Queen puzzle in O(n!)
 * Let p[r] be the column of the queen on the rth row (must be exactly 1 queen per row)
 * There also must be exactly 1 queen per column and hence p must be a permuation of (0 until n)
 * There must be n distinct (col + diag) and n distinct (col - diag) for each queen (else bishop attacks)
 * @return returns a Iterator of solutions 
 *     Each solution is an array p of length n such that p[i] is the column of the queen on the ith row
 */
def nQueens(n: Int): Iterator[Seq[Int]] = 
  (0 until n)

olih

Processing JSON using jq

jq is useful to slice, filter, map and transform structured json data.

Installing jq

On Mac OS

brew install jq

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

danidiaz

A series of reading lists mostly related to functional programming.

DrBoolean

const daggy = require('daggy')
const Task = require('data.task')
const _ = require('lodash')
const kleisli_comp = (f, g) => x => f(x).chain(g)
const compose = (f, g) => x => f(g(x))
const id = x => x

//=============FREE=============
const Free = daggy.taggedSum({Impure: ['x', 'f'], Pure: ['x']})
const {Impure, Pure} = Free