feat(emacs): Small repl things

users/crumb/programs/emacs/modules/lang/syd-lang-nix.el

@@ -1,8 +1,29 @@
 ;;; syd-lang-nix.el -*- lexical-binding: t; -*-
 
+(require 'syd-handle-repl)
+(require 'syd-handle-lookup)
+
+(defun syd-nix-open-nix-repl ()
+  (interactive)
+  ;; If possible, cd to the project root.  Flakes force you to use relative
+  ;; paths, which can be annoying in combination with
+  ;;
+  ;; REVIEW: Should this be something handled by `syd--call-repl-handler'?
+  (-some-> (syd-project-root) cd)
+  (nix-repl)
+  (current-buffer))
+
 (use-package nix-mode
   :mode "\\.nix\\'"
+  :init
+  (add-to-list 'auto-mode-alist
+               (cons (rx "/flake.lock'")
+                     (if (fboundp 'json-mode)
+                         'json-mode
+                       'js-mode)))
   :config
-  (add-hook 'nix-mode-hook #'lsp))
+  (add-hook 'nix-mode-hook #'lsp)
+  (set-popup-rule! "^\\*nixos-options-doc\\*$" :ttl 0 :quit t)
+  (set-repl-handler! 'nix-mode #'syd-nix-open-nix-repl))
 
 (provide 'syd-lang-nix)