1 files changed, 47 insertions, 31 deletions
diff --git a/nixpkgs/nixos/doc/manual/development/option-def.section.md b/nixpkgs/nixos/doc/manual/development/option-def.section.md
index 6a3dc26b99be..227f41d812ff 100644
--- a/nixpkgs/nixos/doc/manual/development/option-def.section.md
+++ b/nixpkgs/nixos/doc/manual/development/option-def.section.md
@@ -4,9 +4,11 @@ Option definitions are generally straight-forward bindings of values to
 option names, like
 
 ```nix
-config = {
-  services.httpd.enable = true;
-};
+{
+  config = {
+    services.httpd.enable = true;
+  };
+}
 ```
 
 However, sometimes you need to wrap an option definition or set of
@@ -18,10 +20,12 @@ If a set of option definitions is conditional on the value of another
 option, you may need to use `mkIf`. Consider, for instance:
 
 ```nix
-config = if config.services.httpd.enable then {
-  environment.systemPackages = [ ... ];
-  ...
-} else {};
+{
+  config = if config.services.httpd.enable then {
+    environment.systemPackages = [ /* ... */ ];
+    # ...
+  } else {};
+}
 ```
 
 This definition will cause Nix to fail with an "infinite recursion"
@@ -30,30 +34,36 @@ on the value being constructed here. After all, you could also write the
 clearly circular and contradictory:
 
 ```nix
-config = if config.services.httpd.enable then {
-  services.httpd.enable = false;
-} else {
-  services.httpd.enable = true;
-};
+{
+  config = if config.services.httpd.enable then {
+    services.httpd.enable = false;
+  } else {
+    services.httpd.enable = true;
+  };
+}
 ```
 
 The solution is to write:
 
 ```nix
-config = mkIf config.services.httpd.enable {
-  environment.systemPackages = [ ... ];
-  ...
-};
+{
+  config = mkIf config.services.httpd.enable {
+    environment.systemPackages = [ /* ... */ ];
+    # ...
+  };
+}
 ```
 
 The special function `mkIf` causes the evaluation of the conditional to
 be "pushed down" into the individual definitions, as if you had written:
 
 ```nix
-config = {
-  environment.systemPackages = if config.services.httpd.enable then [ ... ] else [];
-  ...
-};
+{
+  config = {
+    environment.systemPackages = if config.services.httpd.enable then [ /* ... */ ] else [];
+    # ...
+  };
+}
 ```
 
 ## Setting Priorities {#sec-option-definitions-setting-priorities}
@@ -65,7 +75,9 @@ priority 100 and option defaults have priority 1500.
 You can specify an explicit priority by using `mkOverride`, e.g.
 
 ```nix
-services.openssh.enable = mkOverride 10 false;
+{
+  services.openssh.enable = mkOverride 10 false;
+}
 ```
 
 This definition causes all other definitions with priorities above 10 to
@@ -80,7 +92,9 @@ The functions `mkBefore` and `mkAfter` are equal to `mkOrder 500` and `mkOrder 1
 As an example,
 
 ```nix
-hardware.firmware = mkBefore [ myFirmware ];
+{
+  hardware.firmware = mkBefore [ myFirmware ];
+}
 ```
 
 This definition ensures that `myFirmware` comes before other unordered
@@ -97,13 +111,15 @@ they were declared in separate modules. This can be done using
 `mkMerge`:
 
 ```nix
-config = mkMerge
-  [ # Unconditional stuff.
-    { environment.systemPackages = [ ... ];
-    }
-    # Conditional stuff.
-    (mkIf config.services.bla.enable {
-      environment.systemPackages = [ ... ];
-    })
-  ];
+{
+  config = mkMerge
+    [ # Unconditional stuff.
+      { environment.systemPackages = [ /* ... */ ];
+      }
+      # Conditional stuff.
+      (mkIf config.services.bla.enable {
+        environment.systemPackages = [ /* ... */ ];
+      })
+    ];
+}
 ```