Steve Chavez steve-chavez

I started writing this polemic to answer your question, but I ended up touching on most of my gripes with Haskell in general, not just in a corporate context.

GHC

GHC is a modern compiler with an amazing RTS and tons of features, but I have some issues with it.

Monolithic and Hard to Contribute To

Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

Download Audio from YouTube

-i - ignore errors

-c - continue

-t - use video title as file name

--extract-audio - extract audio track

Developing with Nix

This has been moved to the Matrix AI blog: https://matrix.ai/2018/03/24/developing-with-nix/

Note that if you just to compile a simple C program, and you don't want to fiddle with environments:

nix-shell --packages stdenv

Switching NixOS architecture (32bit -> 64bit)

There are rumors, that you can switch from system architecture just adding 1 configuration option:

nixpkgs.system = "x86_64-linux"

and running nixos-rebuild boot && reboot.

	errno.h - C Error Codes in Linux
	All the Linux/C error codes are listed below.

	I occasionally google C error codes, but always end up grepping through /usr/include to find the answer.

	<<
	UPDATE : 07July2025
	There's a utility named `errno`, part of the `moreutils` package; once installed, you can simply run
	`errno -l`
	to see all possible errno's and their English error message!

	# Minimal example of getting a PostgREST API running from scratch for
	# testing purposes. It uses docker to launch a postgres database and
	# a postgrest api server.

	# This should not be used to deploy a production system but to
	# understand how postgrest works. In particular there is no security
	# implemented, see the docs for more.

	# https://postgrest.org/en/v4.4/

	set imap_user="[email protected]"
	set imap_pass=`/usr/bin/security find-generic-password -w -a '[email protected]' -s 'Gmail'`

	set folder=imaps://imap.gmail.com/
	set spoolfile=+INBOX
	set record="+[Gmail]/Sent Mail"
	set postponed="+[Gmail]/Drafts"

	# https://www.neomutt.org/guide/reference search sleep_time for additional info
	set sleep_time=0 # be faster

	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE GeneralizedNewtypeDeriving #-}

	import Control.Applicative
	import Data.Char
	import Data.List (intersperse)
	import Data.Monoid hiding (All, Any)
	import Data.Foldable hiding (all, any)
	import Prelude hiding (all, any)

	# LVDB - LLOOGG Memory DB
	# Copyriht (C) 2009 Salvatore Sanfilippo <[email protected]>
	# All Rights Reserved

	# TODO
	# - cron with cleanup of timedout clients, automatic dump
	# - the dump should use array startsearch to write it line by line
	# and may just use gets to read element by element and load the whole state.
	# - 'help','stopserver','saveandstopserver','save','load','reset','keys' commands.
	# - ttl with milliseconds resolution 'ttl a 1000'. Check ttl in dump!