Allan Lukwago epicallan

The Indexed State Monad in Haskell, Scala, and C#

Have you ever had to write code that made a complex series of succesive modifications to a single piece of mutable state? (Almost certainly yes.)

Did you ever wish you could make the compiler tell you if a particular operation on the state was illegal at a given point in the modifications? (If you're a fan of static typing, probably yes.)

If that's the case, the indexed state monad can help!

Motivation

##Chai Expect

##Language Chains

to
be
been
is
that
and
have

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

	/*
	* Observable
	*/

	var xs = Rx.Observable.range(0, 3)
	xs.subscribe(log)
	//=> 0
	//=> 1
	//=> 2

	<?php

	/**
	* [list_searcheable_acf list all the custom fields we want to include in our search query]
	* @return [array] [list of custom fields]
	*/
	function list_searcheable_acf(){
	$list_searcheable_acf = array("title", "sub_title", "excerpt_short", "excerpt_long", "xyz", "myACF");
	return $list_searcheable_acf;
	}

	#!/bin/bash

	#
	# Use this script to perform backups of one or more MySQL databases.
	#

	# Databases that you wish to be backed up by this script. You can have any number of databases specified; encapsilate each database name in single quotes and separate each database name by a space.
	#
	# Example:
	# databases=( '__DATABASE_1__' '__DATABASE_2__' )

	{-# LANGUAGE InstanceSigs #-}

	import Control.Applicative
	import Control.Monad
	import Control.Monad.Trans.Writer
	-- Here is a direct style pythagoras function
	-- There are two noticeable things in the function body.
	-- 1. Evaluation order of x * x vs y * y is unknown/implicit.
	-- 2. We don't care what happens to the final value (implicit continuation).
	pyth :: (Floating a) => a -> a -> a

	import Control.Concurrent.MVar

	type Channel a = (ReadPort a, WritePort a)
	type ReadPort a = MVar (Stream a)
	type WritePort a = MVar (Stream a)
	type Stream a = MVar (Item a)
	data Item a = MkItem a (Stream a)

	newChan :: IO (Channel a)
	newChan = do

	{-# LANGUAGE DataKinds, PolyKinds, TypeOperators #-}
	{-# LANGUAGE TypeFamilies, FlexibleInstances, ScopedTypeVariables #-}
	{-# LANGUAGE InstanceSigs #-}

	module TinyServant where

	import Control.Applicative
	import GHC.TypeLits
	import Text.Read
	import Data.Time

	{-# LANGUAGE GADTs, ConstraintKinds, Rank2Types, ImplicitParams #-}

	data Rec fields where
	Rec :: fields => Rec fields

	infixr 1 ?
	(?) :: Rec fields -> (fields => r) -> r
	Rec ? e = e

	record :: Rec (?a :: Int, ?b :: String)