From 5881f5fc532b9397f285104cc8f2702f172f31e1 Mon Sep 17 00:00:00 2001
From: Gerard Vermeulen <gerard.vermeulen@posteo.net>
Date: Thu, 23 Jan 2025 10:55:03 +0100
Subject: [PATCH] Improve tab stop handling and electric operators for Go

---
 README.org | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/README.org b/README.org
index 998275d..4cc0bfa 100644
--- a/README.org
+++ b/README.org
@@ -4509,7 +4509,22 @@ Links to learn [[https://go.dev/][Go]] are:
 #+name: lst:setup-go
 #+begin_src emacs-lisp -n :results silent
 (when (featurep 'treesit)
-  (setopt go-ts-mode-indent-offset 2)
+  (setopt go-ts-mode-indent-offset 8) ; for compatibility with Go tools.
+
+  (defun gots2tabs ()
+    "Set tab stops to 2 spaces locally in current go-ts buffer."
+    (interactive)
+    (when (eq major-mode 'go-ts-mode)
+      (setq-local go-ts-mode-indent-offset 2)
+      (setq-local tab-width 2)))
+
+  (defun gots8tabs ()
+    "Set tab stops to 8 spaces locally in current go-ts buffer."
+    (interactive)
+    (when (eq major-mode 'go-ts-mode)
+      (setq-local go-ts-mode-indent-offset 8)
+      (setq-local tab-width 9)))
+
   (add-to-list 'auto-mode-alist `(,(rx ".go" eos) . go-ts-mode)))
 #+end_src
 
@@ -5264,8 +5279,30 @@ add spaces around operators for [[https://go.dev/][Go]] and [[https://www.python
 #+begin_src emacs-lisp -n :results silent
 (when (ensure-package-installation 'electric-operator)
   ;; electric-operator-mode does not handle all operators in Go correctly.
-  ;; (add-hook 'go-ts-mode-hook  #'electric-operator-mode)
+  (add-hook 'go-ts-mode-hook  #'electric-operator-mode)
   (add-hook 'python-mode-hook #'electric-operator-mode))
+
+(with-eval-after-load 'electric-operator
+  ;; https://go.dev/ref/spec#Operators
+  (apply #'electric-operator-add-rules-for-mode 'go-mode
+           (electric-operator-get-rules-for-mode 'prog-mode))
+  (electric-operator-add-rules-for-mode 'go-mode
+                                        (cons "*" #'electric-operator-c-mode-*)
+                                        (cons "&" #'electric-operator-c-mode-&)
+                                        (cons "++" #'electric-operator-c-mode-++)
+                                        (cons "--" #'electric-operator-c-mode---)
+                                        (cons "!=" " != ")
+                                        (cons "&&" " && ")
+                                        (cons "&^" " &^" )
+                                        (cons "//" " // ")
+                                        (cons ":=" " := ")
+                                        (cons "<-" " <- ")
+                                        (cons "<<" " << ")
+                                        (cons "<=" " <= ")
+                                        (cons "==" " == ")
+                                        (cons ">=" " >= ")
+                                        (cons ">>" " >> ")
+                                        (cons "||" " || ")))
 #+end_src
 
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