1 files changed, 21 insertions, 0 deletions
diff --git a/lib/options.nix b/lib/options.nix
index 8d82a809083b7..afae1769afdd4 100644
--- a/lib/options.nix
+++ b/lib/options.nix
@@ -7,6 +7,7 @@ let
     collect
     concatLists
     concatMap
+    concatMapStringsSep
     elemAt
     filter
     foldl'
@@ -280,6 +281,21 @@ rec {
     if ! isString text then throw "literalDocBook expects a string."
     else { _type = "literalDocBook"; inherit text; };
 
+  /* Transition marker for documentation that's already migrated to markdown
+     syntax.
+  */
+  mdDoc = text:
+    if ! isString text then throw "mdDoc expects a string."
+    else { _type = "mdDoc"; inherit text; };
+
+  /* For use in the `defaultText` and `example` option attributes. Causes the
+     given MD text to be inserted verbatim in the documentation, for when
+     a `literalExpression` would be too hard to read.
+  */
+  literalMD = text:
+    if ! isString text then throw "literalMD expects a string."
+    else { _type = "literalMD"; inherit text; };
+
   # Helper functions.
 
   /* Convert an option, described as a list of the option parts in to a
@@ -325,6 +341,11 @@ rec {
     in "\n- In `${def.file}'${result}"
   ) defs;
 
+  showOptionWithDefLocs = opt: ''
+      ${showOption opt.loc}, with values defined in:
+      ${concatMapStringsSep "\n" (defFile: "  - ${defFile}") opt.files}
+    '';
+
   unknownModule = "<unknown-file>";
 
 }