Add: feature/version-control: smerge + hydra for smerge

closes #5

modules/feature/version-control/autoload.el

@@ -38,6 +38,15 @@ repository root."
       (+vcs*update-header-line)
     (setq-local header-line-format nil)))
 
+;;;###autoload
+(defun +vcs|enable-smerge-mode-maybe ()
+  "Auto-enable `smerge-mode' when merge conflict is detected."
+  (save-excursion
+    (goto-char (point-min))
+    (when (re-search-forward "^<<<<<<< " nil :noerror)
+      (smerge-mode 1)
+      (when +vcs-auto-hydra-smerge (+hydra-smerge/body)))))
+
 ;;;###autoload
 (defun +vcs*update-header-line (&rest _)
   "Show revision details in the header-line, instead of the minibuffer.

modules/feature/version-control/config.el

@@ -2,6 +2,9 @@
 
 (setq vc-make-backup-files nil)
 
+(defvar +vcs-auto-hydra-smerge t
+  "When entering `smerge-mode' automatically open associated hydra.")
+
 (load! +git)
 ;; (load! +hg)
 
@@ -13,3 +16,52 @@
 
   (set! :evil-state 'vc-annotate-mode 'normal)
   (set! :evil-state 'vc-git-log-view-mode 'normal))
+
+(def-package! smerge-mode
+  :init
+  (add-hook 'find-file-hook #'+vcs|enable-smerge-mode-maybe)
+  :config
+  (when (featurep! :feature hydra)
+    (require 'hydra)
+
+    (when (version< emacs-version "26")
+      (defalias 'smerge-keep-upper 'smerge-keep-mine)
+      (defalias 'smerge-keep-lower 'smerge-keep-other)
+      (defalias 'smerge-diff-base-upper 'smerge-diff-base-mine)
+      (defalias 'smerge-diff-upper-lower 'smerge-diff-mine-other)
+      (defalias 'smerge-diff-base-lower 'smerge-diff-base-other))
+
+    (defhydra +hydra-smerge (:color pink
+                             :hint nil
+                             :pre (smerge-mode 1)
+                             ;; Disable `smerge-mode' when quitting hydra if
+                             ;; no merge conflicts remain.
+                             :post (smerge-auto-leave))
+      "
+^Move^       ^Keep^               ^Diff^                 ^Other^
+^^-----------^^-------------------^^---------------------^^-------
+_g_          _b_ase               _<_: upper/base        _C_ombine
+^^           _u_pper              _=_: upper/lower       _r_esolve
+_j_          _l_ower              _>_: base/lower        _R_emove
+_k_          _a_ll                _H_ighlight diff
+^^           _RET_: current       _E_diff
+_G_                                             "
+      ("g" (progn (goto-char (point-min)) (smerge-next)))
+      ("G" (progn (goto-char (point-max)) (smerge-prev)))
+      ("j" smerge-next)
+      ("k" smerge-prev)
+      ("b" smerge-keep-base)
+      ("u" smerge-keep-upper)
+      ("l" smerge-keep-lower)
+      ("a" smerge-keep-all)
+      ("RET" smerge-keep-current)
+      ("\C-m" smerge-keep-current)
+      ("<" smerge-diff-base-upper)
+      ("=" smerge-diff-upper-lower)
+      (">" smerge-diff-base-lower)
+      ("H" smerge-refine)
+      ("E" smerge-ediff)
+      ("C" smerge-combine-with-next)
+      ("r" smerge-resolve)
+      ("R" smerge-kill-current)
+      ("q" nil "cancel" :color blue))))