From 78c68fae91579ccda6f65e55f79316b01c5b654a Mon Sep 17 00:00:00 2001
From: ath3 <ha05190@protonmail.com>
Date: Mon, 1 Nov 2021 20:52:47 +0100
Subject: [PATCH] Implement "Goto next buffer / Goto previous buffer" commands

---
 book/src/keymap.md         |  2 ++
 helix-term/src/commands.rs | 29 +++++++++++++++++++++++++++++
 helix-term/src/keymap.rs   |  2 ++
 3 files changed, 33 insertions(+)

diff --git a/book/src/keymap.md b/book/src/keymap.md
index 4a6f80bb..6bcd09bc 100644
--- a/book/src/keymap.md
+++ b/book/src/keymap.md
@@ -161,6 +161,8 @@ Jumps to various locations.
 | `r`   | Go to references                                 | `goto_reference`           |
 | `i`   | Go to implementation                             | `goto_implementation`      |
 | `a`   | Go to the last accessed/alternate file           | `goto_last_accessed_file`  |
+| `n`   | Go to next buffer                                | `goto_next_buffer`         |
+| `p`   | Go to previous buffer                            | `goto_previous_buffer`     |
 
 #### Match mode
 
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 547a1d75..c1891baf 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -262,6 +262,8 @@ impl Command {
         goto_prev_diag, "Goto previous diagnostic",
         goto_line_start, "Goto line start",
         goto_line_end, "Goto line end",
+        goto_next_buffer, "Goto next buffer",
+        goto_previous_buffer, "Goto previous buffer",
         // TODO: different description ?
         goto_line_end_newline, "Goto line end",
         goto_first_nonwhitespace, "Goto first non-blank in line",
@@ -519,6 +521,33 @@ fn goto_line_start(cx: &mut Context) {
     )
 }
 
+fn goto_next_buffer(cx: &mut Context) {
+    goto_buffer(cx, Direction::Forward);
+}
+
+fn goto_previous_buffer(cx: &mut Context) {
+    goto_buffer(cx, Direction::Backward);
+}
+
+fn goto_buffer(cx: &mut Context, direction: Direction) {
+    let buf_cur = current!(cx.editor).1.id();
+
+    if let Some(pos) = cx.editor.documents.iter().position(|(id, _)| id == buf_cur) {
+        let goto_id = if direction == Direction::Forward {
+            if pos < cx.editor.documents.iter().count() - 1 {
+                cx.editor.documents.iter().nth(pos + 1).unwrap().0
+            } else {
+                cx.editor.documents.iter().next().unwrap().0
+            }
+        } else if pos > 0 {
+            cx.editor.documents.iter().nth(pos - 1).unwrap().0
+        } else {
+            cx.editor.documents.iter().last().unwrap().0
+        };
+        cx.editor.switch(goto_id, Action::Replace);
+    }
+}
+
 fn extend_to_line_start(cx: &mut Context) {
     let (view, doc) = current!(cx.editor);
     goto_line_start_impl(view, doc, Movement::Extend)
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 93f64fa4..b48eea14 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -453,6 +453,8 @@ impl Default for Keymaps {
                 "m" => goto_window_middle,
                 "b" => goto_window_bottom,
                 "a" => goto_last_accessed_file,
+                "n" => goto_next_buffer,
+                "p" => goto_previous_buffer,
             },
             ":" => command_mode,