Add whole word selection commands

helix-core/src/selection.rs

@@ -170,6 +170,15 @@ impl Range {
         self.from() <= pos && pos < self.to()
     }
 
+    /// Returns equal if anchor and head are the same, and disregards old_visual_position. When
+    /// a single character is selected, the orientation (i.e. which is the head and which is the
+    /// anchor) is indistinguishable and should be disregarded.
+    pub fn visual_eq(&self, other: Range) -> bool {
+        self.anchor == other.anchor && self.head == other.head
+            // TODO: this does not work for graphemes like \r\n
+            || self.len() == 1 && self.from() == other.from() && self.to() == other.to()
+    }
+
     /// Map a range through a set of changes. Returns a new range representing
     /// the same position after the changes are applied. Note that this
     /// function runs in O(N) (N is number of changes) and can therefore
@@ -710,6 +719,14 @@ impl Selection {
             }
         }
     }
+
+    /// Returns true if two selections are identical as perceived by the user
+    pub fn visual_eq(&self, other: Selection) -> bool {
+        self.ranges()
+            .iter()
+            .zip(other.ranges().iter())
+            .all(|(&r1, &r2)| r1.visual_eq(r2))
+    }
 }
 
 impl<'a> IntoIterator for &'a Selection {

helix-term/src/commands.rs

@@ -523,6 +523,10 @@ impl MappableCommand {
         surround_delete, "Surround delete",
         select_textobject_around, "Select around object",
         select_textobject_inner, "Select inside object",
+        select_next_word, "Select next whole word",
+        select_next_long_word, "Select next whole long word",
+        select_prev_word, "Select previous whole word",
+        select_prev_long_word, "Select previous whole long word",
         goto_next_function, "Goto next function",
         goto_prev_function, "Goto previous function",
         goto_next_class, "Goto next type definition",
@@ -5454,6 +5458,39 @@ fn select_textobject(cx: &mut Context, objtype: textobject::TextObject) {
     cx.on_next_key(move |cx, event| {
         cx.editor.autoinfo = None;
         if let Some(ch) = event.char() {
+            select_textobject_for_char(cx, ch, objtype, count);
+        }
+    });
+
+    let title = match objtype {
+        textobject::TextObject::Inside => "Match inside",
+        textobject::TextObject::Around => "Match around",
+        _ => return,
+    };
+    let help_text = [
+        ("w", "Word"),
+        ("W", "WORD"),
+        ("p", "Paragraph"),
+        ("t", "Type definition (tree-sitter)"),
+        ("f", "Function (tree-sitter)"),
+        ("a", "Argument/parameter (tree-sitter)"),
+        ("c", "Comment (tree-sitter)"),
+        ("T", "Test (tree-sitter)"),
+        ("e", "Data structure entry (tree-sitter)"),
+        ("m", "Closest surrounding pair (tree-sitter)"),
+        ("g", "Change"),
+        (" ", "... or any character acting as a pair"),
+    ];
+
+    cx.editor.autoinfo = Some(Info::new(title, &help_text));
+}
+
+fn select_textobject_for_char(
+    cx: &mut Context,
+    ch: char,
+    objtype: textobject::TextObject,
+    count: usize,
+) {
     let textobject = move |editor: &mut Editor| {
         let (view, doc) = current!(editor);
         let text = doc.text().slice(..);
@@ -5529,30 +5566,55 @@ fn select_textobject(cx: &mut Context, objtype: textobject::TextObject) {
         doc.set_selection(view.id, selection);
     };
     cx.editor.apply_motion(textobject);
+}
+
+fn select_next_word(cx: &mut Context) {
+    let current_selection = get_current_selection(cx);
+    select_textobject_for_char(cx, 'w', textobject::TextObject::Inside, cx.count());
+    let new_selection = get_current_selection(cx);
+    if current_selection.visual_eq(new_selection) {
+        move_next_word_end(cx);
+        select_textobject_for_char(cx, 'w', textobject::TextObject::Inside, cx.count());
     }
-    });
+}
 
-    let title = match objtype {
+fn select_next_long_word(cx: &mut Context) {
-        textobject::TextObject::Inside => "Match inside",
+    let current_selection = get_current_selection(cx);
-        textobject::TextObject::Around => "Match around",
+    select_textobject_for_char(cx, 'W', textobject::TextObject::Inside, cx.count());
-        _ => return,
+    let new_selection = get_current_selection(cx);
-    };
+    if current_selection.visual_eq(new_selection) {
-    let help_text = [
+        move_next_long_word_end(cx);
-        ("w", "Word"),
+        select_textobject_for_char(cx, 'W', textobject::TextObject::Inside, cx.count());
-        ("W", "WORD"),
+    }
-        ("p", "Paragraph"),
+}
-        ("t", "Type definition (tree-sitter)"),
-        ("f", "Function (tree-sitter)"),
-        ("a", "Argument/parameter (tree-sitter)"),
-        ("c", "Comment (tree-sitter)"),
-        ("T", "Test (tree-sitter)"),
-        ("e", "Data structure entry (tree-sitter)"),
-        ("m", "Closest surrounding pair (tree-sitter)"),
-        ("g", "Change"),
-        (" ", "... or any character acting as a pair"),
-    ];
 
-    cx.editor.autoinfo = Some(Info::new(title, &help_text));
+fn select_prev_word(cx: &mut Context) {
+    let current_selection = get_current_selection(cx);
+    select_textobject_for_char(cx, 'w', textobject::TextObject::Inside, cx.count());
+    flip_selections(cx);
+    let new_selection = get_current_selection(cx);
+    if current_selection.visual_eq(new_selection) {
+        move_prev_word_start(cx);
+        select_textobject_for_char(cx, 'w', textobject::TextObject::Inside, cx.count());
+        flip_selections(cx);
+    }
+}
+
+fn select_prev_long_word(cx: &mut Context) {
+    let current_selection = get_current_selection(cx);
+    select_textobject_for_char(cx, 'W', textobject::TextObject::Inside, cx.count());
+    flip_selections(cx);
+    let new_selection = get_current_selection(cx);
+    if current_selection.visual_eq(new_selection) {
+        move_prev_long_word_start(cx);
+        select_textobject_for_char(cx, 'W', textobject::TextObject::Inside, cx.count());
+        flip_selections(cx);
+    }
+}
+
+fn get_current_selection(cx: &mut Context) -> Selection {
+    let (view, doc) = current!(cx.editor);
+    doc.selection(view.id).clone()
 }
 
 fn surround_add(cx: &mut Context) {