feat: implement buffer jumplist

j.a=":ab"
j.d=":rb"
j.0=":j 0"
j.1=":j 1"
j.2=":j 2"
j.3=":j 3"
j.4=":j 4"

helix-term/src/commands.rs

@@ -3141,6 +3141,7 @@ fn buffer_picker(cx: &mut Context) {
         is_modified: bool,
         is_current: bool,
         focused_at: std::time::Instant,
+        index_in_buffer_jumplist: Option<usize>,
     }
 
     let new_meta = |doc: &Document| BufferMeta {
@@ -3149,6 +3150,11 @@ fn buffer_picker(cx: &mut Context) {
         is_modified: doc.is_modified(),
         is_current: doc.id() == current,
         focused_at: doc.focused_at,
+        index_in_buffer_jumplist: cx
+            .editor
+            .buffer_jumplist
+            .iter()
+            .position(|id| id == &doc.id()),
     };
 
     let mut items = cx
@@ -3171,6 +3177,10 @@ fn buffer_picker(cx: &mut Context) {
             if meta.is_current {
                 flags.push('*');
             }
+            if let Some(index) = meta.index_in_buffer_jumplist {
+                flags.push_str(&index.to_string());
+            }
+
             flags.into()
         }),
         PickerColumn::new("path", |meta: &BufferMeta, _| {

helix-term/src/commands/typed.rs

@@ -99,6 +99,51 @@ fn force_quit(cx: &mut compositor::Context, _args: Args, event: PromptEvent) ->
     Ok(())
 }
 
+fn buffer_jump(cx: &mut compositor::Context, args: Args, event: PromptEvent) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    let pos: usize = args.first().unwrap_or("0").parse().unwrap_or(0);
+    if let Some(doc_id) = cx.editor.buffer_jumplist.get(pos) {
+        cx.editor.switch(*doc_id, Action::Replace);
+    }
+
+    return Ok(());
+}
+
+fn add_buffer_to_jumplist(
+    cx: &mut compositor::Context,
+    _args: Args,
+    event: PromptEvent,
+) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    let current = view!(cx.editor).doc;
+    cx.editor.buffer_jumplist.push(current);
+
+    return Ok(());
+}
+
+fn remove_buffer_from_jumplist(
+    cx: &mut compositor::Context,
+    _args: Args,
+    event: PromptEvent,
+) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    let current = view!(cx.editor).doc;
+    cx.editor
+        .buffer_jumplist
+        .retain(|doc_id| *doc_id != current);
+
+    return Ok(());
+}
+
 fn open(cx: &mut compositor::Context, args: Args, event: PromptEvent) -> anyhow::Result<()> {
     if event != PromptEvent::Validate {
         return Ok(());
@@ -2619,6 +2664,39 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
             ..Signature::DEFAULT
         },
     },
+    TypableCommand {
+        name: "jump-to-buffer",
+        aliases: &["j"],
+        doc: "Switch to a document buffer using its index in the buffer jumplist.",
+        fun: buffer_jump,
+        completer: CommandCompleter::all(completers::filename),
+        signature: Signature {
+            positionals: (1, None),
+            ..Signature::DEFAULT
+        },
+    },
+    TypableCommand {
+        name: "add-buffer-to-jumplist",
+        aliases: &["ab"],
+        doc: "Add the current document buffer to the buffer jumplist.",
+        fun: add_buffer_to_jumplist,
+        completer: CommandCompleter::all(completers::filename),
+        signature: Signature {
+            positionals: (0, None),
+            ..Signature::DEFAULT
+        },
+    },
+    TypableCommand {
+        name: "remove-buffer-from-jumplist",
+        aliases: &["rb"],
+        doc: "Remove the current document buffer from the buffer jumplist.",
+        fun: remove_buffer_from_jumplist,
+        completer: CommandCompleter::all(completers::filename),
+        signature: Signature {
+            positionals: (0, None),
+            ..Signature::DEFAULT
+        },
+    },
     TypableCommand {
         name: "buffer-close",
         aliases: &["bc", "bclose"],

helix-view/src/editor.rs

@@ -1123,6 +1123,9 @@ pub struct Editor {
 
     pub mouse_down_range: Option<Range>,
     pub cursor_cache: CursorCache,
+
+    /// Stores a manually curated list of document IDs for navigation.
+    pub buffer_jumplist: Vec<DocumentId>,
 }
 
 pub type Motion = Box<dyn Fn(&mut Editor)>;
@@ -1245,6 +1248,7 @@ impl Editor {
             handlers,
             mouse_down_range: None,
             cursor_cache: CursorCache::default(),
+            buffer_jumplist: Vec::new(),
         }
     }
 
@@ -1824,6 +1828,9 @@ impl Editor {
         // This will also disallow any follow-up writes
         self.saves.remove(&doc_id);
 
+        // Removes the document from the buffer jumplist when closed.
+        self.buffer_jumplist.retain(|doc| *doc != doc_id);
+
         enum Action {
             Close(ViewId),
             ReplaceDoc(ViewId, DocumentId),