From c3d4b57b89e629a114b9ce8afb414c7cb2f38de9 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Sun, 16 Apr 2023 10:44:03 -0400
Subject: [PATCH] Add `optionalString` to manual Nix lang utilities

---
 doc/manual/generate-manpage.nix | 24 +++++++++++++-----------
 doc/manual/utils.nix            |  2 ++
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/doc/manual/generate-manpage.nix b/doc/manual/generate-manpage.nix
index 0b3a238019bb..f23750d985bb 100644
--- a/doc/manual/generate-manpage.nix
+++ b/doc/manual/generate-manpage.nix
@@ -37,13 +37,12 @@ let
          `${command}` [*option*...] ${arguments}
         '';
 
-      maybeSubcommands = if details ? commands && details.commands != {}
-        then ''
+      maybeSubcommands = optionalString (details ? commands && details.commands != {})
+         ''
            where *subcommand* is one of the following:
 
            ${subcommands}
-         ''
-        else "";
+         '';
 
       subcommands = if length categories > 1
         then listCategories
@@ -65,10 +64,9 @@ let
         * [`${command} ${name}`](./${appendName filename name}.md) - ${subcmd.description}
       '';
 
-      maybeDocumentation =
-        if details ? doc
-        then replaceStrings ["@stores@"] [storeDocs] details.doc
-        else "";
+      maybeDocumentation = optionalString
+        (details ? doc)
+        (replaceStrings ["@stores@"] [storeDocs] details.doc);
 
       maybeOptions = if details.flags == {} then "" else ''
         # Options
@@ -80,15 +78,19 @@ let
         let
           allOptions = options // commonOptions;
           showCategory = cat: ''
-            ${if cat != "" then "**${cat}:**" else ""}
+            ${optionalString (cat != "") "**${cat}:**"}
 
             ${listOptions (filterAttrs (n: v: v.category == cat) allOptions)}
             '';
           listOptions = opts: concatStringsSep "\n" (attrValues (mapAttrs showOption opts));
           showOption = name: option:
             let
-              shortName = if option ? shortName then "/ `-${option.shortName}`" else "";
-              labels = if option ? labels then (concatStringsSep " " (map (s: "*${s}*") option.labels)) else "";
+              shortName = optionalString
+                (option ? shortName)
+                ("/ `-${option.shortName}`");
+              labels = optionalString
+                (option ? labels)
+                (concatStringsSep " " (map (s: "*${s}*") option.labels));
             in trim ''
               - `--${name}` ${shortName} ${labels}
 
diff --git a/doc/manual/utils.nix b/doc/manual/utils.nix
index 82544935a494..6c62ed3907d4 100644
--- a/doc/manual/utils.nix
+++ b/doc/manual/utils.nix
@@ -42,6 +42,8 @@ rec {
   filterAttrs = pred: set:
     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
 
+  optionalString = cond: string: if cond then string else "";
+
   showSetting = { useAnchors }: name: { description, documentDefault, defaultValue, aliases, value }:
     let
       result = squash ''