programs: integrate nvimpager into man to make text reflow correctly

also get marginally better syntax highlighting! the cursor movements are a little strange, but overall net improvement

TODO.md

@@ -46,8 +46,6 @@
 
 ## IMPROVEMENTS:
 - sane-deadlines: show day of the week for upcoming items
-- `man`: reflow text when resized
-  - most likely solution is to use a HTML pager: <https://unix.stackexchange.com/a/11413>
 - curlftpfs: replace with something better
   - safer (rust? actively maintained? sandboxable?)
   - handles spaces/symbols in filenames

hosts/common/programs/assorted.nix

@@ -91,6 +91,7 @@ in
       "nmap"
       "nmcli"
       "nmon"
+      "nvimpager"
       "nvme-cli"  # nvme
       # "openssl"
       "parted"

hosts/common/programs/default.nix

@@ -133,6 +133,7 @@
     ./nmcli.nix
     ./notejot.nix
     ./ntfy-sh.nix
+    ./nvimpager.nix
     ./nwg-panel
     ./objdump.nix
     ./obsidian.nix

hosts/common/programs/less.nix

@@ -15,9 +15,11 @@
     # - --use-color = enable color instead of just monochrome (highlights search matches)
     # SYSTEMD_LESS defaults to FRSXMK
     env = rec {
+      # MANPAGER = "less";
       PAGER = "less";
       LESS = "--incsearch --LONG-PROMPT --quit-if-one-screen --quit-on-intr --RAW-CONTROL-CHARS --shift=.2 --use-color";
       SYSTEMD_LESS = LESS;  #< used by journalctl
     };
+    mime.priority = 200;  # fallback to more specialized pagers where exists
   };
 }

hosts/common/programs/neovim/vimrc

@@ -29,3 +29,10 @@ set conceallevel=2
 " source: https://www.reddit.com/r/neovim/comments/chlmfk/highlight_trailing_whitespaces_in_neovim/
 set list
 set listchars=tab:▷\·,trail:·,extends:◣,precedes:◢,nbsp:○
+
+" when using vim to view manpages
+"   (`:Man topic` or `MANPAGER='nvim +Man!' man topic` or `vim man://topic`),
+" instruct `man` to output unwrapped buffers, and let vim soft-wrap them.
+" this allows one to resize the terminal and have the manpage be re-rendered.
+" see: <https://github.com/neovim/neovim/issues/11436>
+let g:man_hardwrap=0

hosts/common/programs/nvimpager.nix

@@ -0,0 +1,24 @@
+{ config, pkgs, ... }:
+{
+  sane.programs.nvimpager = {
+    packageUnwrapped = (pkgs.nvimpager.override {
+      neovim = config.sane.programs.neovim.packageUnwrapped;
+    }).overrideAttrs {
+      # check phase fails, something to do with me enabling plugins not expected by the tester
+      doCheck = false;
+    };
+
+    suggestedPrograms = [ "neovim" ];
+
+    sandbox.whitelistWayland = true;  # for system clipboard integration
+
+    env.MANPAGER = "nvimpager";
+    # env.PAGER = "nvimpager";
+    # `man 2 select` will have `man` render the manpage to plain text, then pipe it into vim for syntax highlighting.
+    # force MANWIDTH=999 to make `man` not hard-wrap any lines, and instead let vim soft-wrap lines.
+    # that allows the document to be responsive to screen-size/windowing changes.
+    # MANROFFOPT = "-c" improves the indentation, but i'm not totally sure what it actually does.
+    env.MANWIDTH = "999";
+    env.MANROFFOPT = "-c";
+  };
+}