feat(commands): sibling selections

helix-core/src/object.rs

@@ -1,23 +1,18 @@
 use crate::{Range, RopeSlice, Selection, Syntax};
 
-pub fn expand_selection(syntax: &Syntax, text: RopeSlice, selection: &Selection) -> Selection {
-    let tree = syntax.tree();
-
-    selection.clone().transform(|range| {
+pub fn expand_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    selection.transform(|range| {
         let from = text.char_to_byte(range.from());
         let to = text.char_to_byte(range.to());
 
         // find parent of a descendant that matches the range
-        let parent = match tree
-            .root_node()
-            .descendant_for_byte_range(from, to)
-            .and_then(|node| {
-                if node.start_byte() == from && node.end_byte() == to {
-                    node.parent()
-                } else {
-                    Some(node)
-                }
-            }) {
+        let parent = match node_under_range(syntax, text, &range).and_then(|node| {
+            if node.start_byte() == from && node.end_byte() == to {
+                node.parent()
+            } else {
+                Some(node)
+            }
+        }) {
             Some(parent) => parent,
             None => return range,
         };
@@ -33,14 +28,9 @@ pub fn expand_selection(syntax: &Syntax, text: RopeSlice, selection: &Selection)
     })
 }
 
-pub fn shrink_selection(syntax: &Syntax, text: RopeSlice, selection: &Selection) -> Selection {
-    let tree = syntax.tree();
-
-    selection.clone().transform(|range| {
-        let from = text.char_to_byte(range.from());
-        let to = text.char_to_byte(range.to());
-
-        let descendant = match tree.root_node().descendant_for_byte_range(from, to) {
+pub fn shrink_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    selection.transform(|range| {
+        let descendant = match node_under_range(syntax, text, &range) {
             // find first child, if not possible, fallback to the node that contains selection
             Some(descendant) => match descendant.child(0) {
                 Some(child) => child,
@@ -59,3 +49,54 @@ pub fn shrink_selection(syntax: &Syntax, text: RopeSlice, selection: &Selection)
         }
     })
 }
+
+#[inline(always)]
+pub fn next_sibling_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    transform_node_under_selection(syntax, text, selection, tree_sitter::Node::next_sibling)
+}
+
+#[inline(always)]
+pub fn prev_sibling_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    transform_node_under_selection(syntax, text, selection, tree_sitter::Node::prev_sibling)
+}
+
+fn transform_node_under_selection<'a, F>(
+    syntax: &'a Syntax,
+    text: RopeSlice,
+    selection: Selection,
+    f: F,
+) -> Selection
+where
+    F: Fn(&tree_sitter::Node<'a>) -> Option<tree_sitter::Node<'a>>,
+{
+    selection.transform(|range| {
+        let next_sibling = match node_under_range(syntax, text, &range) {
+            // find first child, if not possible, fallback to the node that contains selection
+            Some(descendant) => match f(&descendant) {
+                Some(sib) => sib,
+                None => return range,
+            },
+            None => return range,
+        };
+
+        let from = text.byte_to_char(next_sibling.start_byte());
+        let to = text.byte_to_char(next_sibling.end_byte());
+
+        if range.head < range.anchor {
+            Range::new(to, from)
+        } else {
+            Range::new(from, to)
+        }
+    })
+}
+
+pub fn node_under_range<'a>(
+    syntax: &'a Syntax,
+    text: RopeSlice,
+    range: &Range,
+) -> Option<tree_sitter::Node<'a>> {
+    let tree = syntax.tree();
+    let from = text.char_to_byte(range.from());
+    let to = text.char_to_byte(range.to());
+    tree.root_node().descendant_for_byte_range(from, to)
+}

helix-term/src/commands.rs

@@ -363,6 +363,8 @@ impl MappableCommand {
         rotate_selection_contents_backward, "Rotate selections contents backward",
         expand_selection, "Expand selection to parent syntax node",
         shrink_selection, "Shrink selection to previously expanded syntax node",
+        next_sibling_selection, "Move selection to next sibling syntax node",
+        prev_sibling_selection, "Move selection to previous sibling syntax node",
         jump_forward, "Jump forward on jumplist",
         jump_backward, "Jump backward on jumplist",
         save_selection, "Save the current selection to the jumplist",
@@ -5490,7 +5492,7 @@ fn expand_selection(cx: &mut Context) {
             // save current selection so it can be restored using shrink_selection
             view.object_selections.push(current_selection.clone());
 
-            let selection = object::expand_selection(syntax, text, current_selection);
+            let selection = object::expand_selection(syntax, text, current_selection.clone());
             doc.set_selection(view.id, selection);
         }
     };
@@ -5516,7 +5518,37 @@ fn shrink_selection(cx: &mut Context) {
         // if not previous selection, shrink to first child
         if let Some(syntax) = doc.syntax() {
             let text = doc.text().slice(..);
-            let selection = object::shrink_selection(syntax, text, current_selection);
+            let selection = object::shrink_selection(syntax, text, current_selection.clone());
+            doc.set_selection(view.id, selection);
+        }
+    };
+    motion(cx.editor);
+    cx.editor.last_motion = Some(Motion(Box::new(motion)));
+}
+
+fn next_sibling_selection(cx: &mut Context) {
+    let motion = |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 = object::next_sibling_selection(syntax, text, current_selection.clone());
+            doc.set_selection(view.id, selection);
+        }
+    };
+    motion(cx.editor);
+    cx.editor.last_motion = Some(Motion(Box::new(motion)));
+}
+
+fn prev_sibling_selection(cx: &mut Context) {
+    let motion = |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 = object::prev_sibling_selection(syntax, text, current_selection.clone());
             doc.set_selection(view.id, selection);
         }
     };

helix-term/src/keymap.rs

@@ -570,12 +570,14 @@ impl Default for Keymaps {
                 "D" => goto_first_diag,
                 "space" => add_newline_above,
                 "o" => shrink_selection,
+                "s" => prev_sibling_selection,
             },
             "]" => { "Right bracket"
                 "d" => goto_next_diag,
                 "D" => goto_last_diag,
                 "space" => add_newline_below,
                 "o" => expand_selection,
+                "s" => next_sibling_selection,
             },
 
             "/" => search,