From 66a90130a5f99d769e9f6034025297f78ecaa3ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 6 Aug 2021 11:22:01 +0900
Subject: [PATCH] Implement selection rotation with `(` and `)`

---
 book/src/keymap.md         |  2 ++
 helix-term/src/commands.rs | 21 +++++++++++++++++++++
 helix-term/src/keymap.rs   |  6 ++----
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/book/src/keymap.md b/book/src/keymap.md
index a33d3dcd..99a76c78 100644
--- a/book/src/keymap.md
+++ b/book/src/keymap.md
@@ -76,6 +76,8 @@
 | `Alt-;`  | Flip selection cursor and anchor                                  |
 | `C`      | Copy selection onto the next line                                 |
 | `Alt-C`  | Copy selection onto the previous line                             |
+| `(`      | Rotate main selection forward                                     |
+| `)`      | Rotate main selection backward                                    |
 | `%`      | Select entire file                                                |
 | `x`      | Select current line, if already selected, extend to next line     |
 | `X`      | Extend selection to line bounds (line-wise selection)             |
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 622a3ebd..7facb556 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -275,6 +275,8 @@ impl Command {
         completion, "Invoke completion popup",
         hover, "Show docs for item under cursor",
         toggle_comments, "Comment/uncomment selections",
+        rotate_selections_forward, "Rotate selections forward",
+        rotate_selections_backward, "Rotate selections backward",
         expand_selection, "Expand selection to parent syntax node",
         jump_forward, "Jump forward on jumplist",
         jump_backward, "Jump backward on jumplist",
@@ -3747,6 +3749,25 @@ fn toggle_comments(cx: &mut Context) {
     doc.append_changes_to_history(view.id);
 }
 
+fn rotate_selections(cx: &mut Context, direction: Direction) {
+    let count = cx.count();
+    let (view, doc) = current!(cx.editor);
+    let mut selection = doc.selection(view.id).clone();
+    let index = selection.primary_index();
+    let len = selection.len();
+    selection.set_primary_index(match direction {
+        Direction::Forward => (index + count) % len,
+        Direction::Backward => (index + (len.saturating_sub(count) % len)) % len,
+    });
+    doc.set_selection(view.id, selection);
+}
+fn rotate_selections_forward(cx: &mut Context) {
+    rotate_selections(cx, Direction::Forward)
+}
+fn rotate_selections_backward(cx: &mut Context) {
+    rotate_selections(cx, Direction::Backward)
+}
+
 // tree sitter node selection
 
 fn expand_selection(cx: &mut Context) {
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index ef283a63..9a18c3b7 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -451,7 +451,8 @@ impl Default for Keymaps {
             // & align selections
             // _ trim selections
 
-            // C / altC = copy (repeat) selections on prev/next lines
+            "(" => rotate_selections_backward,
+            ")" => rotate_selections_forward,
 
             "esc" => normal_mode,
             "C-b" | "pageup" => page_up,
@@ -508,9 +509,6 @@ impl Default for Keymaps {
             "\"" => select_register,
             "C-z" => suspend,
         });
-        // TODO: decide whether we want normal mode to also be select mode (kakoune-like), or whether
-        // we keep this separate select mode. More keys can fit into normal mode then, but it's weird
-        // because some selection operations can now be done from normal mode, some from select mode.
         let mut select = normal.clone();
         select.merge_nodes(keymap!({ "Select mode"
             "h" | "left" => extend_char_left,