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A funky shell thingy that I've never seen before

So you're in posix sh and you want to do the equivalent of this in bash:

foo | tee >(bar) >(baz) >/dev/null

(Suppose that bar and baz don't produce output. Add redirections where needed if that's not the case.)

@safareli
safareli / phantom_container.js.md
Last active October 12, 2016 07:43
Phantom `empty` value and Phantom container compatible with Fantasy Land

See WIP implementation HERE

In Haskell we can define Monoid instances like this:

instance Monoid b => Monoid (Identity b) where
  mempty = mempty
  mappend (Identity a) (Identity b) = Identity (a `mappend` b)

instance (Monoid a, Monoid b) => Monoid (Pair a b) where

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
@dypsilon
dypsilon / reader.js
Last active April 28, 2024 08:50
Example usage of the reader monad.
/**
* This short program will encrypt the user password
* and insert a new record into a mock database.
*/
const Reader = require('fantasy-readers');
const R = require('ramda');
const crypto = require('crypto');
// our mock database
const database = [
@DrBoolean
DrBoolean / binary_baby.js
Created January 7, 2016 21:04
State Monad is useful example
import State, {get, put, modify} from 'fantasy-states'
import {prop, compose, map, chain, merge, always} from 'ramda'
// Unfortunately Binary Gendered Baby Page
//==========================================
const babies = [{id: 2, name: 'Anjali', sex: 'F'}, {id: 3, name: 'Antonio', sex: 'M'}]
// isFemale :: Baby -> Bool
@DrBoolean
DrBoolean / mcft.js
Created December 30, 2015 04:44
Monoidal Contravariant Functors and Transducers
const daggy = require('daggy');
const {foldMap} = require('pointfree-fantasy')
const {concat, toUpper, prop, identity, range, compose} = require('ramda');
// Contravariant functors usually have this shape F(a -> ConcreteType).
// In other words, some type holding a function which is parametric on its input, but not output.
// They don't always have that shape, but it's a good intuition
// Covariant functors are what we're used to, which are parametric in their output
//================================================================
@DrBoolean
DrBoolean / falg.js
Created December 15, 2015 18:19
F-algebra es2015
const daggy = require('daggy')
const {compose, curry, map, prop, identity, intersection, union} = require('ramda');
const inspect = (x) => { if(!x) return x; return x.inspect ? x.inspect() : x; }
// F-algebras
// Fix
// ============
// Fx is a simple wrapper that does almost nothing. It's much more useful in typed languages to check that we have a recursive f (Fix f)
@runarorama
runarorama / Adjunctions.scala
Last active December 2, 2019 19:58
Free/forgetful adjunctions
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.
@paf31
paf31 / ListT.purs
Created August 27, 2015 04:03
Stack-safe ListT in PureScript using FreeT
module Control.Monad.List.Trans where
import Prelude
import Data.List
import Data.Either
import Control.Apply
import Control.Bind
import Control.Monad.Eff
@Thimoteus
Thimoteus / settimeout.purs
Last active August 29, 2015 14:23
Synchronous setTimeout with Purescript and the ContT monad
module Main where
import Data.Function
import Debug.Trace
import Control.Monad.Trans
import Control.Monad.Cont.Trans
import Control.Monad.Eff
foreign import data Timeout :: !
type Milliseconds = Number