feat(emacs): Support Nix's ''big quotes''

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

@@ -26,6 +26,15 @@
   (set-popup-rule! (rx bol "*nixos-options-doc*" eol) :ttl 0 :quit t)
   (set-repl-handler! 'nix-mode #'syd-nix-open-nix-repl)
   (dolist (c '(?- ?_))
-    (modify-syntax-entry c "w" nix-mode-syntax-table)))
+    (modify-syntax-entry c "w" nix-mode-syntax-table))
+
+  ;; Inform Smartparens and Evil-surround of Nix's alternative string syntax.
+  (with-eval-after-load 'smartparens
+    (sp-local-pair 'nix-mode "''" "''"))
+  (syd-add-hook 'nix-mode-hook
+    (defun syd-nix--configure-evil-surround-h ()
+      (with-eval-after-load 'evil-surround
+        (push '(?Q . ("''" . "''"))
+              evil-surround-pairs-alist)))))
 
 (provide 'syd-lang-nix)