Merge pull request #2 from djacu/lesson/intro-to-types

Added a lesson on basic nixos module option types.

lessons/010-basic-types/config.nix

@@ -0,0 +1,8 @@
+{...}: {
+  config = {
+    exBool = true;
+    exInt = 42;
+    exEnum = "left";
+    exStr = "hello";
+  };
+}

lessons/010-basic-types/eval.nix

@@ -0,0 +1,15 @@
+let
+  pkgs = import <nixpkgs> {};
+  inherit (pkgs) lib;
+in
+  #lib.generators.toPretty
+  #{}
+  (
+    pkgs.lib.evalModules {
+      modules = [
+        ./options.nix
+        ./config.nix
+      ];
+    }
+  )
+  .config

lessons/010-basic-types/lesson.md

@@ -0,0 +1,18 @@
+# Basic Types
+
+In this lesson, we will cover some basic types.
+There are certainly [many more types][nixos-manual-basic-types], but for this lesson, we will focus on just a few.
+
+Notice in the [options][options] file, we have declared boolean, enumeration, integer, and string options.
+
+[//]: # (./options.nix)
+
+Notice in the [config][config] file, we have declared values for all these options.
+
+[//]: # (./config.nix)
+
+If you execute the run file (`./run`), you should see an output that matches what we have configured.
+
+[nixos-manual-basic-types]: https://nixos.org/manual/nixos/stable/#sec-option-types
+[options]: ./options.nix
+[config]: ./config.nix

lessons/010-basic-types/options.nix

@@ -0,0 +1,22 @@
+{lib, ...}: let
+  inherit (lib) types;
+in {
+  options = {
+    exBool = lib.mkOption {
+      type = types.bool;
+      description = "My example boolean.";
+    };
+    exEnum = lib.mkOption {
+      type = types.enum ["left" "right"];
+      description = "My example enumeration.";
+    };
+    exInt = lib.mkOption {
+      type = types.int;
+      description = "My example integer.";
+    };
+    exStr = lib.mkOption {
+      type = types.str;
+      description = "My example string.";
+    };
+  };
+}

lessons/010-basic-types/run

@@ -0,0 +1 @@
+nix eval -f eval.nix --json | nix run nixpkgs#jq -- .