Add nix development setup

.Rbuildignore

@@ -18,3 +18,6 @@
 ^README\.Rmd$
 ^tools/aaaaa-coding-helpers\.R$
 ^\.vscode$
+^flake\.lock$
+^flake\.nix$
+^\.envrc$

.envrc

@@ -0,0 +1,6 @@
+# shellcheck shell=bash
+if ! has nix_direnv_version || ! nix_direnv_version 3.1.0; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.1.0/direnvrc" "sha256-yMJ2OVMzrFaDPn7q8nCBZFRYpL/f0RcHzhmw/i6btJM="
+fi
+use vim
+use flake

.gitignore

@@ -17,3 +17,12 @@ inst/doc
 
 docs
 tools/coding-helpers.R
+
+# nix -----------------------------------------------
+
+# Ignore build outputs from performing a nix-build or `nix build` command
+result
+result-*
+
+# Ignore direnv folder
+.direnv/

flake.nix

@@ -0,0 +1,51 @@
+{
+  description = "A basic flake with a shell";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  inputs.systems.url = "github:nix-systems/default";
+  inputs.flake-utils = {
+    url = "github:numtide/flake-utils";
+    inputs.systems.follows = "systems";
+  };
+
+  outputs =
+    { nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          packages = [
+            pkgs.bashInteractive
+            (pkgs.rWrapper.override {
+              packages = with pkgs.rPackages; [
+                decor
+                devtools
+                dplyr
+                graph
+                igraph
+                knitr
+                languageserver
+                Matrix
+                Matrix
+                pcalg
+                processx
+                rextendr
+                Rgraphviz
+                rhub
+                rlang
+                rmarkdown
+                S7
+                testthat
+                tibble
+                tidyr
+                tidyverse
+                usethis
+              ];
+            })
+          ];
+        };
+      }
+    );
+}