Leonid Kovnatskiy altV

What is the appeal of dynamically-typed languages?

Kris Nuttycombe asks:

I genuinely wish I understood the appeal of unityped languages better. Can someone who really knows both well-typed and unityped explain?

I think the terms well-typed and unityped are a bit of question-begging here (you might as well say good-typed versus bad-typed), so instead I will say statically-typed and dynamically-typed.

I'm going to approach this article using Scala to stand-in for static typing and Python for dynamic typing. I feel like I am credibly proficient both languages: I don't currently write a lot of Python, but I still have affection for the language, and have probably written hundreds of thousands of lines of Python code over the years.

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

I have tried a lot of solutions for IP-camera streams.

Old solutions

Vitamio.https://github.com/yixia/Vitamio-iOS
Result: random crashes and not working cameras
https://github.com/kolyvan/kxmovie
Result: compile time error. I haven't successfully integrated it to my project.
GStreamer. https://github.com/sdroege/gst-player

Atom Clojure Setup

This describes how I setup Atom for an ideal Clojure development workflow. This fixes indentation on newlines, handles parentheses, etc. The keybinding settings for enter (in keymap.cson) are important to get proper newlines with indentation at the right level. There are other helpers in init.coffee and keymap.cson that are useful for cutting, copying, pasting, deleting, and indenting Lisp expressions.

Install Atom

Download Atom

The Atom documentation is excellent. It's highly worth reading the flight manual.

In this article, I will share some of my experience on installing NVIDIA driver and CUDA on Linux OS. Here I mainly use Ubuntu as example. Comments for CentOS/Fedora are also provided as much as I can.

	#!/bin/bash
	apt-get -y update
	apt-get -y install nginx-extras build-essential libpcre3-dev libssl-dev libgeoip-dev libpq-dev libxslt1-dev libgd2-xpm-dev
	wget -c https://openresty.org/download/openresty-1.13.6.2.tar.gz
	tar zxvf openresty-1.13.6.2.tar.gz
	cd openresty-1.13.6.2

	./configure \
	--sbin-path=/usr/sbin/nginx \
	--conf-path=/etc/nginx/nginx.conf \

	#!/bin/bash

	file_tree()
	{
	pid="$1"

	indentation=$(printf "%${indent}s")

	[[ "$$" -eq "$pid" ]] && printf "$yellow"
	echo "$indentation"$(ps -o pid= -o cmd= -p $pid \| perl -pe 's/^\s+// ; s/\s+/,/')

	{-# LANGUAGE GADTs #-} -- Soft dependent types
	{-# LANGUAGE PolyKinds #-} -- Allow general specification of Refl
	{-# LANGUAGE RankNTypes #-} -- Explicit quantification and inline type context
	{-# LANGUAGE DataKinds #-} -- Lift data constructors to Kind level
	{-# LANGUAGE TypeFamilies #-} -- Equational reasoning about types
	{-# LANGUAGE TypeOperators #-} -- Allow types such as :~:

	-- Starting the interactive shell:
	--
	-- ghci -XDataKinds -XTypeOperators -Wall -Werror Script.hs

	# HTTP crawler inside nginx.
	#
	# start crawling by curl http://127.0.0.1:18080/?host=<START URL>
	#

	worker_processes auto;

	events {
	worker_connections 16384;
	}