Alex atcol

Top HN posts

Using the nipkgs unstable channel

Motivation

There a times when you need to build something from the nix unstable channel. For example the master contains a new package you need, but the next nixpkgs release is somewhere in the future, and you need this package now. In this guide I want to show how to install packages from unstable by using nix-env. Furthermore I hope to give a basic understanding of the channels concept.

What are nix channels?

A channel is a set of expressions which includes severall build, installation and configuration instructions for packages, services and the system itself. The repository normaly used here is nixpkgs. It is developed at https://github.com/NixOS/nixpkgs.

What is the nix unstable channel?

The unstable channel is a copy of the NixOS/nixpkgs master. It is pulled from github once in a while and will be available from a mirror under https://nixos.org/channels/nixpkgs-unstable. Since NixOS uses half-anual released stable channels, some changes (especially new f

Interview Questions

Kotlin

Q1: What is a primary constructor in Kotlin? ☆☆

Answer: The primary constructor is part of the class header. Unlike Java, you don't need to declare a constructor in the body of the class. Here's an example:

Nix Flake MVP

Goals

To provide Nix repositories with an easy and standard way to reference other Nix repositories.
To allow such references to be queried and updated automatically.
To provide a replacement for nix-channel, NIX_PATH and Hydra

Movies Recommendation:

MovieLens - Movie Recommendation Data Sets http://www.grouplens.org/node/73
Yahoo! - Movie, Music, and Images Ratings Data Sets http://webscope.sandbox.yahoo.com/catalog.php?datatype=r
Jester - Movie Ratings Data Sets (Collaborative Filtering Dataset) http://www.ieor.berkeley.edu/~goldberg/jester-data/
Cornell University - Movie-review data for use in sentiment-analysis experiments http://www.cs.cornell.edu/people/pabo/movie-review-data/

Music Recommendation:

Last.fm - Music Recommendation Data Sets http://www.dtic.upf.edu/~ocelma/MusicRecommendationDataset/index.html

	use std::fmt::Display;

	/*
	money = currency_symbol number ;
	currency_symbol = '$' \| '£' \| '€' ;
	number = INTEGER ;
	*/

	#[derive(Debug, PartialEq, Clone, Copy)]
	enum TokenType {

	# accompanying blog - https://kaushikc.org/posts/matrix-jitsi-nixos.html
	# /etc/nixos/configuration.nix


	imports =
	let
	nur-no-pkgs =
	import (
	builtins.fetchTarball
	"https://github.com/nix-community/NUR/archive/master.tar.gz"

	Below are the Big O performance of common functions of different Java Collections.


	List \| Add \| Remove \| Get \| Contains \| Next \| Data Structure
	---------------------\|------\|--------\|------\|----------\|------\|---------------
	ArrayList \| O(1) \| O(n) \| O(1) \| O(n) \| O(1) \| Array
	LinkedList \| O(1) \| O(1) \| O(n) \| O(n) \| O(1) \| Linked List
	CopyOnWriteArrayList \| O(n) \| O(n) \| O(1) \| O(n) \| O(1) \| Array

	{
	"folders": [{
	"follow_symlinks": true,
	"path": "."
	}],
	"settings": {
	"detect_indentation": false,
	"ensure_newline_at_eof_on_save": true,
	"tab_size": 2,
	"file_exclude_patterns": [

	import java.util.*;
	import java.util.function.*;
	import java.util.stream.*;

	import static java.util.stream.Collectors.*;
	import static java.util.Comparator.*;

	/**
	* http://stackoverflow.com/questions/22845574/how-to-dynamically-do-filtering-in-java-8
	*