melvic-ybanez

What I Didn't Know about Functional Programming until 2020

1. Programming using a series of transformations and aggregations, something I've been doing for years, is known as programming in the map/reduce style.
2. The more abstract the type is, the greater its cardinality, and the smaller the set of operations it supports. So make use of universal quantifiers, particularly by implementing fully parametric functions. They guide you on how to implement their term-level definitions by narrowing down the number of possible implementations. In other words, the type system of Scala (or Haskell, for that matter) is not only great for capturing compile-time errors, but is also capable of leading you to the correct solution.
3. You can encode union types by combining different Scala features such as type constructors, subtyping and implicits, and by taking advantage of the Curry-Howard Isomorphism and De Morgan's Laws for neg

Yord

Warcaster

Dice

• AD: White Action Dice
• PD: Red Power Dice

Your Force

• Models: Units and Void Gates

ww9

Blogging with Gist

Gist simplicity can turn blogging into a liberating experience.

Pros	Cons
✅ Free, simple, fast, hassle-free	❌ Image upload in comments only
✅ Tagging	❌ No post pinning
✅ Search	❌ Doesn't look like a blog
✅ Revisions	❌ Unfriendly URLs

Yord

// Paste e.g. in https://scastie.scala-lang.org

object Foo {
  def main(args: Array[String]): Unit = {
    def some[A](a: A): Option[A] = Some(a)
    
    val inc: Int => Int = _ + 1
    
    println(
      map(inc)(List(1, 2, 3, 4))

ipbastola

JQ to filter JSON by value

Syntax: cat <filename> | jq -c '.[] | select( .<key> | contains("<value>"))'

Example: To get json record having _id equal 611

cat my.json | jq -c '.[] | select( ._id | contains(611))'

Remember: if JSON value has no double quotes (eg. for numeric) to do not supply in filter i.e. in contains(611)

Yord

// If you haven't already, watch Brian Lonsdorf's "Hey Underscore, You're Doing It Wrong!":
// http://functionaltalks.org/2013/05/27/brian-lonsdorf-hey-underscore-youre-doing-it-wrong/

const { append, eqProps, identity, map, mergeWith, nthArg, pipe, reject, when } = require('Ramda');

const idEquals = eqProps('id');



// Reducers as data-less action function (returns a function that

apolloclark

Postgres Cheatsheet

This is a collection of the most common commands I run while administering Postgres databases. The variables shown between the open and closed tags, "<" and ">", should be replaced with a name you choose. Postgres has multiple shortcut functions, starting with a forward slash, "". Any SQL command that is not a shortcut, must end with a semicolon, ";". You can use the keyboard UP and DOWN keys to scroll the history of previous commands you've run.

Setup

installation, Ubuntu

http://www.postgresql.org/download/linux/ubuntu/ https://help.ubuntu.com/community/PostgreSQL

oleksii-zavrazhnyi

DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )

Is a useful one-liner which will give you the full directory name of the script no matter where it is being called from

These will work as long as the last component of the path used to find the script is not a symlink (directory links are OK). If you want to also resolve any links to the script itself, you need a multi-line solution:

SOURCE="${BASH_SOURCE[0]}"
while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink

runarorama

sealed trait Interact[A]

case class Ask(prompt: String)
  extends Interact[String]

case class Tell(msg: String)
  extends Interact[Unit]

trait Monad[M[_]] {
  def pure[A](a: A): M[A]

rxaviers

People

:bowtie:	😄 :smile:	😆 :laughing:
😊 :blush:	😃 :smiley:	☺️ :relaxed:
😏 :smirk:	😍 :heart_eyes:	😘 :kissing_heart:
😚 :kissing_closed_eyes:	😳 :flushed:	😌 :relieved:
😆 :satisfied:	😁 :grin:	😉 :wink:
😜 :stuck_out_tongue_winking_eye:	😝 :stuck_out_tongue_closed_eyes:	😀 :grinning:
😗 :kissing:	😙 :kissing_smiling_eyes:	😛 :stuck_out_tongue: