Christoph Siedlerchr

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

async/await is just the do-notation of the Promise monad

CertSimple just wrote a blog post arguing ES2017's async/await was the best thing to happen with JavaScript. I wholeheartedly agree.

In short, one of the (few?) good things about JavaScript used to be how well it handled asynchronous requests. This was mostly thanks to its Scheme-inherited implementation of functions and closures. That, though, was also one of its worst faults, because it led to the "callback hell", an seemingly unavoidable pattern that made highly asynchronous JS code almost unreadable. Many solutions attempted to solve that, but most failed. Promises almost did it, but failed too. Finally, async/await is here and, combined with Promises, it solves the problem for good. On this post, I'll explain why that is the case and trace a link between promises, async/await, the do-notation and monads.

First, let's illustrate the 3 styles by implementing

Generate ssl certificates with Subject Alt Names on OSX

We're going to generate a key per project which includes multiple fully qualified domains. This key can be checked into the project repo as it's intended for local development but never used on production servers.

Save ssl.conf to your my_project directory.

Open ssl.conf in a text editor.

Edit the domain(s) listed under the [alt_names] section so that they match the local domain name you want to use for your project, e.g.

	$userPath = $env:USERPROFILE
	$pathExclusions = New-Object System.Collections.ArrayList
	$processExclusions = New-Object System.Collections.ArrayList

	$pathExclusions.Add('C:\Windows\Microsoft.NET') > $null
	$pathExclusions.Add('C:\Windows\assembly') > $null
	$pathExclusions.Add($userPath + '\AppData\Local\Microsoft\VisualStudio') > $null
	$pathExclusions.Add('C:\ProgramData\Microsoft\VisualStudio\Packages') > $null
	$pathExclusions.Add('C:\Program Files (x86)\MSBuild') > $null
	$pathExclusions.Add('C:\Program Files (x86)\Microsoft Visual Studio 14.0') > $null

	#!/bin/sh -x

	set -e

	SIZES="
	16,16x16
	32,16x16@2x
	32,32x32
	64,32x32@2x
	128,128x128

	package net.aquadc.common
	// Gist: https://gist.github.com/Miha-x64/5f626228b34175f827734596d6701008

	import java.util.*

	// maps

	inline fun <reified K : Enum<K>, V> enumMapOf(): MutableMap<K, V> {
	return EnumMap<K, V>(K::class.java)
	}

	[Windows Only - Change JAVA PATH - http://stackoverflow.com/questions/26864662/how-to-solve-the-error-the-system-cannot-find-the-file-c-programdata-oracle-ja]

	cd C:\ProgramData\Oracle\Java\javapath

	del java*.exe

	mklink java.exe "C:\Program Files\Java\jdk1.8.0_91\bin\java.exe"
	mklink javaw.exe "C:\Program Files\Java\jdk1.8.0_91\bin\javaw.exe"
	mklink javaws.exe "C:\Program Files\Java\jdk1.8.0_91\bin\javaws.exe"

	# Backup
	docker exec CONTAINER /usr/bin/mysqldump -u root --password=root DATABASE > backup.sql

	# Restore
	cat backup.sql \| docker exec -i CONTAINER /usr/bin/mysql -u root --password=root DATABASE

	docker logs nginx 2>&1 \| grep "127."

	# ref: http://stackoverflow.com/questions/34724980/finding-a-string-in-docker-logs-of-container

	META-INF/
	*.class