neovim/clipboard: init module

modules/neovim/init/clipboard.nix

@@ -0,0 +1,80 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  inherit (lib.modules) mkIf;
+  inherit (lib.options) mkOption mkEnableOption mkPackageOption;
+  inherit (lib.types) nullOr either str listOf submodule;
+  inherit (lib.attrsets) mapAttrs mapAttrsToList filterAttrs;
+  cfg = config.vim.clipboard;
+in {
+  options = {
+    vim = {
+      clipboard = {
+        enable = mkEnableOption ''
+          clipboard management for Neovim. Users may still choose to manage their
+          clipboard through [](#opt-vim.options) should they wish to avoid using
+          this module.
+        '';
+
+        registers = mkOption {
+          type = either str (listOf str);
+          default = "";
+          example = "unnamedplus";
+          description = ''
+            The register to be used by the Neovim clipboard. Recognized types are:
+
+            * unnamed: Vim will use the clipboard register `"*"` for all yank, delete,
+              change and put operations which would normally go to the unnamed register.
+
+            * unnamedplus: A variant of the "unnamed" flag which uses the clipboard register
+            `"+"` ({command}`:h quoteplus`) instead of register `"*"` for all yank, delete,
+            change and put operations which would normally go to the unnamed register.
+
+            When `unnamed` and `unnamedplus` is included simultaneously yank and delete
+            operations (but not put) will additionally copy the text into register `"*"`.
+
+            Please see  {command}`:h clipboard` for more details.
+
+          '';
+        };
+
+        providers = mkOption {
+          type = submodule {
+            options = let
+              clipboards = {
+                # name = "package name";
+                wl-copy = "wl-clipboard";
+                xclip = "xclip";
+                xsel = "xsel";
+              };
+            in
+              mapAttrs (name: pname: {
+                enable = mkEnableOption name;
+                package = mkPackageOption pkgs pname {nullable = true;};
+              })
+              clipboards;
+          };
+          default = {};
+          description = ''
+            Clipboard providers for which packages will be added to nvf's
+            {option}`extraPackages`. The `package` field may be set to `null`
+            if related packages are already found in system packages to
+            potentially reduce closure sizes.
+          '';
+        };
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    vim = {
+      options.clipboard = cfg.registers;
+      extraPackages = mapAttrsToList (_: v: v.package) (
+        filterAttrs (_: v: v.enable && v.package != null) cfg.providers
+      );
+    };
+  };
+}