From bd4d1466ac9456df32adae5dbc6f3d8e5b31a2c8 Mon Sep 17 00:00:00 2001
From: Jackson <jrmoffet@gmail.com>
Date: Tue, 2 Jan 2024 20:56:53 -0700
Subject: [PATCH] Clear jumplist implementation

---
 book/src/generated/typable-cmd.md |  1 +
 helix-term/src/commands/typed.rs  | 33 +++++++++++++++++++++++++++++++
 helix-view/src/view.rs            | 17 ++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/book/src/generated/typable-cmd.md b/book/src/generated/typable-cmd.md
index f4fcb6f62..5b8e27075 100644
--- a/book/src/generated/typable-cmd.md
+++ b/book/src/generated/typable-cmd.md
@@ -84,5 +84,6 @@
 | `:run-shell-command`, `:sh` | Run a shell command |
 | `:reset-diff-change`, `:diffget`, `:diffg` | Reset the diff change at the cursor position. |
 | `:clear-register` | Clear given register. If no argument is provided, clear all registers. |
+| `:clear-jumplist`, `:clj` | Pops items from the jump list. If not argument is provided, clear the jump list. |
 | `:redraw` | Clear and re-render the whole UI |
 | `:move` | Move the current buffer and its corresponding file to a different path |
diff --git a/helix-term/src/commands/typed.rs b/helix-term/src/commands/typed.rs
index f530ce10d..ef976d50d 100644
--- a/helix-term/src/commands/typed.rs
+++ b/helix-term/src/commands/typed.rs
@@ -2385,6 +2385,32 @@ fn clear_register(
     Ok(())
 }
 
+fn clear_jumplist(
+    cx: &mut compositor::Context,
+    args: &[Cow<str>],
+    event: PromptEvent,
+) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+    ensure!(args.len() <= 1, ":clear-jumplist takes at most 1 argument");
+
+    let doc = doc!(cx.editor);
+    let view = view_mut!(cx.editor);
+    let selection = doc.selection(view.id);
+    if args.len() == 1 {
+        let to_remove = args[0].parse::<usize>()?;
+        view.jumps.remove_from_head(to_remove);
+    } else {
+        view.jumps.clear();
+    }
+    if view.jumps.len() == 0 {
+        // Fixup cases where the jumplist is emptied into an invalid state
+        view.jumps.push((doc.id(), selection.clone()));
+    }
+    Ok(())
+}
+
 fn redraw(
     cx: &mut compositor::Context,
     _args: &[Cow<str>],
@@ -3075,6 +3101,13 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
         fun: clear_register,
         signature: CommandSignature::none(),
     },
+    TypableCommand {
+        name: "clear-jumplist",
+        aliases: &["clj"],
+        doc: "Pops items from the jump list. If not argument is provided, clear the jump list.",
+        fun: clear_jumplist,
+        signature: CommandSignature::none(),
+    },
     TypableCommand {
         name: "redraw",
         aliases: &[],
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index e5e2641a8..08ddeb93f 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -84,6 +84,23 @@ impl JumpList {
         self.jumps.iter()
     }
 
+    pub fn remove_from_head(&mut self, to_remove: usize) {
+        for _ in 0..to_remove {
+            if self.jumps.pop_front().is_none() {
+                break;
+            }
+        }
+        self.current = self.jumps.len();
+    }
+
+    pub fn clear(&mut self) {
+        self.jumps.clear();
+    }
+
+    pub fn len(&self) -> usize {
+        self.jumps.len()
+    }
+
     /// Applies a [`Transaction`] of changes to the jumplist.
     /// This is necessary to ensure that changes to documents do not leave jump-list
     /// selections pointing to parts of the text which no longer exist.