add node boundary movement

5 files changed, 329 insertions, 1 deletions

diff --git a/helix-core/src/movement.rs b/helix-core/src/movement.rs
index 2b29f36d..6c4f3f53 100644
--- a/helix-core/src/movement.rs
+++ b/helix-core/src/movement.rs
@@ -16,7 +16,7 @@ use crate::{
     syntax::LanguageConfiguration,
     text_annotations::TextAnnotations,
     textobject::TextObject,
-    visual_offset_from_block, Range, RopeSlice,
+    visual_offset_from_block, Range, RopeSlice, Selection, Syntax,
 };
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -556,6 +556,85 @@ pub fn goto_treesitter_object(
     last_range
 }
 
+fn find_parent_start(mut node: Node) -> Option<Node> {
+    let start = node.start_byte();
+
+    while node.start_byte() >= start || !node.is_named() {
+        node = node.parent()?;
+    }
+
+    Some(node)
+}
+
+pub fn move_parent_node_end(
+    syntax: &Syntax,
+    text: RopeSlice,
+    selection: Selection,
+    dir: Direction,
+    movement: Movement,
+) -> Selection {
+    let tree = syntax.tree();
+
+    selection.transform(|range| {
+        let start_from = text.char_to_byte(range.from());
+        let start_to = text.char_to_byte(range.to());
+
+        let mut node = match tree
+            .root_node()
+            .named_descendant_for_byte_range(start_from, start_to)
+        {
+            Some(node) => node,
+            None => {
+                log::debug!(
+                    "no descendant found for byte range: {} - {}",
+                    start_from,
+                    start_to
+                );
+                return range;
+            }
+        };
+
+        let mut end_head = match dir {
+            // moving forward, we always want to move one past the end of the
+            // current node, so use the end byte of the current node, which is an exclusive
+            // end of the range
+            Direction::Forward => text.byte_to_char(node.end_byte()),
+
+            // moving backward, we want the cursor to land on the start char of
+            // the current node, or if it is already at the start of a node, to traverse up to
+            // the parent
+            Direction::Backward => {
+                let end_head = text.byte_to_char(node.start_byte());
+
+                // if we're already on the beginning, look up to the parent
+                if end_head == range.cursor(text) {
+                    node = find_parent_start(node).unwrap_or(node);
+                    text.byte_to_char(node.start_byte())
+                } else {
+                    end_head
+                }
+            }
+        };
+
+        if movement == Movement::Move {
+            // preserve direction of original range
+            if range.direction() == Direction::Forward {
+                Range::new(end_head, end_head + 1)
+            } else {
+                Range::new(end_head + 1, end_head)
+            }
+        } else {
+            // if we end up with a forward range, then adjust it to be one past
+            // where we want
+            if end_head >= range.anchor {
+                end_head += 1;
+            }
+
+            Range::new(range.anchor, end_head)
+        }
+    })
+}
+
 #[cfg(test)]
 mod test {
     use ropey::Rope;
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index bf60ad71..fc01eec7 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -247,6 +247,8 @@ impl MappableCommand {
         move_prev_long_word_start, "Move to start of previous long word",
         move_next_long_word_end, "Move to end of next long word",
         move_prev_long_word_end, "Move to end of previous long word",
+        move_parent_node_end, "Move to end of the parent node",
+        move_parent_node_start, "Move to beginning of the parent node",
         extend_next_word_start, "Extend to start of next word",
         extend_prev_word_start, "Extend to start of previous word",
         extend_next_word_end, "Extend to end of next word",
@@ -255,6 +257,8 @@ impl MappableCommand {
         extend_prev_long_word_start, "Extend to start of previous long word",
         extend_next_long_word_end, "Extend to end of next long word",
         extend_prev_long_word_end, "Extend to end of prev long word",
+        extend_parent_node_end, "Extend to end of the parent node",
+        extend_parent_node_start, "Extend to beginning of the parent node",
         find_till_char, "Move till next occurrence of char",
         find_next_char, "Move to next occurrence of char",
         extend_till_char, "Extend till next occurrence of char",
@@ -4605,6 +4609,46 @@ fn select_prev_sibling(cx: &mut Context) {
     select_sibling_impl(cx, &|node| Node::prev_sibling(&node))
 }
 
+fn move_node_bound_impl(cx: &mut Context, dir: Direction, movement: Movement) {
+    let motion = move |editor: &mut Editor| {
+        let (view, doc) = current!(editor);
+
+        if let Some(syntax) = doc.syntax() {
+            let text = doc.text().slice(..);
+            let current_selection = doc.selection(view.id);
+
+            let selection = movement::move_parent_node_end(
+                syntax,
+                text,
+                current_selection.clone(),
+                dir,
+                movement,
+            );
+
+            doc.set_selection(view.id, selection);
+        }
+    };
+
+    motion(cx.editor);
+    cx.editor.last_motion = Some(Motion(Box::new(motion)));
+}
+
+pub fn move_parent_node_end(cx: &mut Context) {
+    move_node_bound_impl(cx, Direction::Forward, Movement::Move)
+}
+
+pub fn move_parent_node_start(cx: &mut Context) {
+    move_node_bound_impl(cx, Direction::Backward, Movement::Move)
+}
+
+pub fn extend_parent_node_end(cx: &mut Context) {
+    move_node_bound_impl(cx, Direction::Forward, Movement::Extend)
+}
+
+pub fn extend_parent_node_start(cx: &mut Context) {
+    move_node_bound_impl(cx, Direction::Backward, Movement::Extend)
+}
+
 fn match_brackets(cx: &mut Context) {
     let (view, doc) = current!(cx.editor);
     let is_select = cx.editor.mode == Mode::Select;
diff --git a/helix-term/src/keymap/default.rs b/helix-term/src/keymap/default.rs
index 37983352..419e376f 100644
--- a/helix-term/src/keymap/default.rs
+++ b/helix-term/src/keymap/default.rs
@@ -88,6 +88,8 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
         "A-i" | "A-down" => shrink_selection,
         "A-p" | "A-left" => select_prev_sibling,
         "A-n" | "A-right" => select_next_sibling,
+        "A-e" => move_parent_node_end,
+        "A-b" => move_parent_node_start,
 
         "%" => select_all,
         "x" => extend_line_below,
@@ -336,6 +338,9 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
         "B" => extend_prev_long_word_start,
         "E" => extend_next_long_word_end,
 
+        "A-e" => extend_parent_node_end,
+        "A-b" => extend_parent_node_start,
+
         "n" => extend_search_next,
         "N" => extend_search_prev,
 
diff --git a/helix-term/tests/test/commands.rs b/helix-term/tests/test/commands.rs
index b13c37bc..b3e13551 100644
--- a/helix-term/tests/test/commands.rs
+++ b/helix-term/tests/test/commands.rs
@@ -2,6 +2,7 @@ use helix_term::application::Application;
 
 use super::*;
 
+mod movement;
 mod write;
 
 #[tokio::test(flavor = "multi_thread")]
diff --git a/helix-term/tests/test/commands/movement.rs b/helix-term/tests/test/commands/movement.rs
new file mode 100644
index 00000000..03dc7ba9
--- /dev/null
+++ b/helix-term/tests/test/commands/movement.rs
@@ -0,0 +1,199 @@
+use super::*;
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_move_parent_node_end() -> anyhow::Result<()> {
+    let tests = vec![
+        // single cursor stays single cursor, first goes to end of current
+        // node, then parent
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        "no#["|]#
+                    }
+                }
+            "##}),
+            "<A-e>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"#[\n|]#
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"#[\n|]#
+                    }
+                }
+            "}),
+            "<A-e>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"
+                    }#[\n|]#
+                }
+            "}),
+        ),
+        // select mode extends
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        #["no"|]#
+                    }
+                }
+            "##}),
+            "v<A-e><A-e>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        #[\"no\"
+                    }\n|]#
+                }
+            "}),
+        ),
+    ];
+
+    for test in tests {
+        test_with_config(AppBuilder::new().with_file("foo.rs", None), test).await?;
+    }
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_move_parent_node_start() -> anyhow::Result<()> {
+    let tests = vec![
+        // single cursor stays single cursor, first goes to end of current
+        // node, then parent
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        "no#["|]#
+                    }
+                }
+            "##}),
+            "<A-b>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        #[\"|]#no\"
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"#[\n|]#
+                    }
+                }
+            "}),
+            "<A-b>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else #[{|]#
+                        \"no\"
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else #[{|]#
+                        \"no\"
+                    }
+                }
+            "}),
+            "<A-b>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } #[e|]#lse {
+                        \"no\"
+                    }
+                }
+            "}),
+        ),
+        // select mode extends
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        #["no"|]#
+                    }
+                }
+            "##}),
+            "v<A-b><A-b>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else #[|{
+                        ]#\"no\"
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        #["no"|]#
+                    }
+                }
+            "##}),
+            "v<A-b><A-b><A-b>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } #[|else {
+                        ]#\"no\"
+                    }
+                }
+            "}),
+        ),
+    ];
+
+    for test in tests {
+        test_with_config(AppBuilder::new().with_file("foo.rs", None), test).await?;
+    }
+
+    Ok(())
+}