thiloho

Getting started with the Nix ecosystem

What is this article about?

When I first started to learn how to use NixOS, the Nix package manager, and how to work with the Nix language, I was overwhelmed. While it did not take me too long to (sort of) get into it, it was not the most pleasant experience. I would say that there is not really a single source of truth, like Arch Linux users have with the ArchWiki, where you can basically look up everything. Instead, the information is spread across many different sources, which can make it difficult for beginners to find out how to do what they want to do.

The "modern nix CLI", also known as "nix3 cli", is another thing that can cause confusion when you are just starting your nix journey. There are some commands that look almost exactly the same, such as nix shell compared to nix-shell or nix-build compa

illustris

import sys
import functools

callstack = []

@functools.cache
def lookup(func):
    try:
        parts = func.split(":")
        with open(parts[0]) as f:

VictorTaelin

Implementing complex numbers and FFT with just datatypes (no floats)

In this article, I'll explain why implementing numbers with just algebraic datatypes is desirable. I'll then talk about common implementations of FFT (Fast Fourier Transform) and why they hide inherent inefficiencies. I'll then show how to implement integers and complex numbers with just algebraic datatypes, in a way that is extremely simple and elegant. I'll conclude by deriving a pure functional implementation of complex FFT with just datatypes, no floats.

toraritte

Yes, there are several ways to do this, but none of them are as direct and simple as git v2.1.2; htop v1.2.3 and come with a lot of caveats.

aside
Specifying versions for programming language packages are possible too, but that topic seems to be even messier. The most promising standardization effort to date is [dream2nix][1].

0. Methods

That is, available at the time of this writing:

0.1 "versioned" attribute paths (if available)

voidus

{
  description = "A nixos cloudinit base image without nixos-infect";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs";
  };

  outputs = { self, nixpkgs }:
  let
    system = "x86_64-linux";

dkandalov

import com.intellij.coverage.CoverageExecutor
import com.intellij.execution.ExecutorRegistry
import com.intellij.execution.RunManager
import com.intellij.execution.RunnerAndConfigurationSettings
import com.intellij.execution.application.ApplicationConfiguration
import com.intellij.execution.application.ApplicationConfigurationType
import com.intellij.execution.executors.DefaultDebugExecutor
import com.intellij.execution.executors.DefaultRunExecutor
import com.intellij.execution.junit.JUnitConfiguration
import com.intellij.execution.junit.JUnitConfigurationType

ClassicDarkChocolate

function Get-ScoopRoot {
    $scoopdir = & {
        $env:SCOOP, (scoop config 'rootPath'), "$env:USERPROFILE\scoop" | Where-Object { -not [String]::IsNullOrEmpty($_) } | Select-Object -First 1
    } 6>$null
    $scoopdir
}

function Get-ScoopPackageVersions {
    param (
        [Parameter(Position = 1, Mandatory = $true)]

InternetUnexplorer

# Adapted from https://github.com/bennofs/nix-index/blob/master/command-not-found.sh

command_not_found_handle () {
    if [ -n "${MC_SID-}" ] || ! [ -t 1 ]; then
        >&2 echo "$1: command not found"
        return 127
    fi

    echo -n "searching nix-index..."
    ATTRS=$(@nix-locate@ --minimal --no-group --type x --type s --top-level --whole-name --at-root "/bin/$1")

sorki

# Module for configuring libvirt with static NixOS networking
# instead of using libvirt managed bridge.

{ config, lib, pkgs, ... }:
with lib;

let
  cfg = config.virtualisation.libvirtd.networking;
  v6Enabled = cfg.ipv6.network != null;
  v6PLen = toInt (elemAt (splitString "/" cfg.ipv6.network) 1);

udf

The Setup

I wanted to write a module that generates multiple systemd services and timers to scrub some zfs pools at certain intervals. The default scrub config does not support individual scrub intervals for each pool.

I want the config to look like this:

{
  services.zfs-auto-scrub = {
 tank = "Sat *-*-* 00:00:00";