jaq

Jaq is a data wrangling tool focusing on correctness, speed, and simplicity

1. Install Nix

   Arch Linux

   Bash

   $ pacman --sync --refresh --noconfirm curl git jq nix

   Debian

   Bash

   $ apt install --yes curl git jq nix

   Ubuntu

   Bash

   $ apt install --yes curl git jq nix

2. Download a configuration file

   # default.nix
   {
     ngipkgs ? import (fetchTarball "https://github.com/ngi-nix/ngipkgs/tarball/main") { },
   }:
   ngipkgs.demo-shell (
     { ... }:
   
     {
       programs.jaq.enable = true;
     }
   
   )
   

   Download
3. Enable binary substituters

   Bash

   $ export NIX_CONFIG='substituters = https://cache.nixos.org/ https://ngi.cachix.org/
   trusted-public-keys = cache.nixos.org-1:6nchdd59x431o0gwypbmraurkbj16zpmqfgspcdshjy= ngi.cachix.org-1:n+cal72roc3qqulxihpv+tw5t42whxmmhpragkrsrow='

4. Build and run a virtual machine

   Arch Linux, Debian Sid and Ubuntu 25.04

   Bash

   $ nix-build ./default.nix && ./result

   Debian 12 and Ubuntu 24.04/24.10

   Bash

   $ rev=$(nix-instantiate --eval --attr sources.nixpkgs.rev https://github.com/ngi-nix/ngipkgs/archive/master.tar.gz | jq --raw-output)

   $ nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/$rev.tar.gz --packages nix --run "nix-build ./default.nix && ./result"

5. Usage Instructions

   A demo shell for testing jaq, a data wrangling tool with formal semantics similar to jq.

   Let's get a basic understanding of jaq's capabilities:

   Here, we can pass in a set or object full of numbers and have jaq add them together.

   $ echo '{"a": 1, "b": 2}' | jaq 'add' # equal to 3

   We can also do more complicated operations like mapping over a list and using conditionals:

   $ echo '[0, 1, 2, 3]' | jaq 'map(.*2) | [.[] | select(. < 5)] | add' # equal to 6

   Finally, jaq will fail if any malformed input is passed

   $ echo "0, 1, 4, " | jaq

{ ... }:

{
  programs.jaq.enable = true;
}

This project is funded by NLnet through these subgrants:

• jaq
• Polyglot-jaq