build(nix): Add Nix-based dev environment configuration

Author: PetarKirov

.direnv/.gitkeep

@@ -0,0 +1,9 @@
+# shellcheck shell=bash
+
+if ! has nix_direnv_version || ! nix_direnv_version 1.6.1; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/1.6.1/direnvrc" "sha256-aFwy76WtzXD7SVXWetpg+welXMZI/VcEUPQ2WUMXYSY="
+fi
+
+dotenv_if_exists
+nix_direnv_watch_file shell.nix
+use flake

.envrc

@@ -8,3 +8,10 @@ __test__library__
 *.swp
 
 dlang-tour-test-library
+
+# Nix build artifact:
+result
+
+# Direnv:
+.direnv/*
+!.direnv/.gitkeep

.gitignore

@@ -0,0 +1,15 @@
+{
+  description = "Dlang Tour";
+
+  inputs = {
+    nixpkgs.url = github:NixOS/nixpkgs/nixos-unstable;
+    flake-utils.url = github:numtide/flake-utils;
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.simpleFlake {
+      inherit self nixpkgs;
+      name = "dlang-tour";
+      shell = ./shell.nix;
+    };
+}

flake.lock

@@ -0,0 +1,17 @@
+{ pkgs ? import <nixpkgs> { } }: with pkgs;
+mkShell {
+  buildInputs = [
+    figlet
+    glibc.static
+    zlib.static
+    (openssl.override { static = true; }).dev
+    dmd
+    dtools
+    dub
+    ldc
+  ];
+
+  shellHook = ''
+    figlet "Welcome  to Dlang Tour"
+  '';
+}