Aaron William West tallpeak

WARNING This list outdated, for the up to date version visit https://haskellcosm.com

List of companies that use Haskell in Production

Types of work:

RD - research&development
PR - product
IP - in-house product
CO - consulting

Working with SQL syntax trees in F#

Update 12/15/2016 - Added Sql generation

Welcome to my blog post for #FsAdvent 2016.

If you're using a relational database, as your application grows in size, at some point you may find yourself looking for an SQL parser. This can give you lots of leverage, for example allowing you to:

Do permission checks on queries before executing them
Rewrite incorrect or inefficient queries

Type classes

Type classes have some advantages over Java style interfaces. One advantage is the ability to implement functions that do not need to take in an instance of the interface.

For example, (FromString v) takes in a String and returns v, and it doesn't have to take v as a parameter.

Useful PostgreSQL Queries & Commands

All sizes in MB, change /1024/1024 to /1024/1024/1024 for GB.

Databases sizes

Without system databases

select
datname as database,
(pg_database_size(datname)/1024/1024) as size

	#SingleInstance, Force
	#NoEnv ; somewhat ironic...

	; this won't work in vista/7 if it's not run as an administrator.
	; i'm too lazy to request it manually so the easiest way is to
	; compile this script, and then under Compatibility tab in the
	; compiled exe's Properties select "Run as Administrator"

	RegRead, P, HKLM, SYSTEM\CurrentControlSet\Control\Session Manager\Environment, PATH

	#Requires AutoHotkey v2.0

	AppVol(Target := "A", Level := 0) {
	if (Target ~= "^[-+]?\d+$") {
	Level := Target
	Target := "A"
	} else if (SubStr(Target, -4) = ".exe") {
	Target := "ahk_exe " Target
	}
	try {

	{-# LANGUAGE DefaultSignatures #-}
	{-# LANGUAGE DeriveAnyClass #-}
	{-# LANGUAGE DeriveGeneric #-}
	{-# LANGUAGE EmptyDataDeriving #-}
	{-# LANGUAGE FlexibleContexts #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE OverloadedStrings #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE TypeApplications #-}