Cut/Yank multiple words

src/core_editor/editor.rs

@@ -1,14 +1,33 @@
+use std::slice::SliceIndex;
+
 use super::{edit_stack::EditStack, Clipboard, ClipboardMode, LineBuffer};
 use crate::enums::{EditType, UndoBehavior};
 use crate::{core_editor::get_default_clipboard, EditCommand};
 
+// Determines how we update the cut buffer when we next cut
+enum LastCutCommand {
+    // We are currently running a command that includes a cut command.
+    This,
+    // We have just run a command that includes a cut command.
+    Last,
+    // We have not recently run a cut command. Replace the cut buffer if another cut happens.
+    BeforeLast,
+}
+
+// Which direction are we cutting in?
+enum CutDirection {
+    Left,
+    Right,
+}
+
 /// Stateful editor executing changes to the underlying [`LineBuffer`]
 ///
 /// In comparison to the state-less [`LineBuffer`] the [`Editor`] keeps track of
 /// the undo/redo history and has facilities for cut/copy/yank/paste
 pub struct Editor {
     line_buffer: LineBuffer,
     cut_buffer: Box<dyn Clipboard>,
+    last_cut_command: LastCutCommand,
 
     edit_stack: EditStack<LineBuffer>,
     last_undo_behavior: UndoBehavior,
@@ -19,6 +38,7 @@ impl Default for Editor {
         Editor {
             line_buffer: LineBuffer::new(),
             cut_buffer: Box::new(get_default_clipboard()),
+            last_cut_command: LastCutCommand::BeforeLast,
             edit_stack: EditStack::new(),
             last_undo_behavior: UndoBehavior::CreateUndoPoint,
         }
@@ -96,8 +116,14 @@ impl Editor {
             EditCommand::CutLeftBefore(c) => self.cut_left_until_char(*c, true, true),
             EditCommand::MoveLeftUntil(c) => self.move_left_until_char(*c, false, true),
             EditCommand::MoveLeftBefore(c) => self.move_left_until_char(*c, true, true),
+            EditCommand::StopCutting => self.last_cut_command = LastCutCommand::BeforeLast,
         }
 
+        self.last_cut_command = match self.last_cut_command {
+            LastCutCommand::This => LastCutCommand::Last,
+            LastCutCommand::Last | LastCutCommand::BeforeLast => LastCutCommand::BeforeLast,
+        };
+
         let new_undo_behavior = match (command, command.edit_type()) {
             (_, EditType::MoveCursor) => UndoBehavior::MoveCursor,
             (EditCommand::InsertChar(c), EditType::EditText) => UndoBehavior::InsertCharacter(*c),
@@ -213,147 +239,155 @@ impl Editor {
         self.last_undo_behavior = undo_behavior;
     }
 
+    // Only updates the cut buffer if the range is not empty.
+    fn maybe_cut<T>(&mut self, cut_range: T, mode: ClipboardMode, direction: CutDirection)
+    where
+        T: SliceIndex<str, Output = str> + std::ops::RangeBounds<usize> + Clone,
+    {
+        let cut_slice = &self.line_buffer.get_buffer()[cut_range.clone()];
+        if !cut_slice.is_empty() {
+            // If the last command was also a cut then we want to keep accumulating in the cut buffer.
+            // Otherwise, replace what's in the cut buffer.
+            let buf;
+            let cut_slice = match (&self.last_cut_command, direction) {
+                (LastCutCommand::BeforeLast, _) => cut_slice,
+                (_, CutDirection::Left) => {
+                    let existing = self.cut_buffer.get().0;
+                    buf = format!("{cut_slice}{existing}");
+                    &buf
+                }
+                (_, CutDirection::Right) => {
+                    let existing = self.cut_buffer.get().0;
+                    buf = format!("{existing}{cut_slice}");
+                    &buf
+                }
+            };
+
+            self.cut_buffer.set(cut_slice, mode);
+
+            let start = match cut_range.start_bound() {
+                std::ops::Bound::Included(start) => *start,
+                std::ops::Bound::Excluded(start) => *start + 1,
+                std::ops::Bound::Unbounded => 0,
+            };
+            self.line_buffer.set_insertion_point(start);
+            self.line_buffer.clear_range(cut_range);
+        }
+        self.last_cut_command = LastCutCommand::This;
+    }
+
     fn cut_current_line(&mut self) {
         let deletion_range = self.line_buffer.current_line_range();
 
-        let cut_slice = &self.line_buffer.get_buffer()[deletion_range.clone()];
-        if !cut_slice.is_empty() {
-            self.cut_buffer.set(cut_slice, ClipboardMode::Lines);
-            self.line_buffer.set_insertion_point(deletion_range.start);
-            self.line_buffer.clear_range(deletion_range);
-        }
+        self.maybe_cut(
+            deletion_range.clone(),
+            ClipboardMode::Lines,
+            // FIXME: what do other shells do here?
+            CutDirection::Right,
+        );
     }
 
     fn cut_from_start(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
-        if insertion_offset > 0 {
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[..insertion_offset],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_to_insertion_point();
-        }
+        self.maybe_cut(
+            0..insertion_offset,
+            ClipboardMode::Normal,
+            CutDirection::Left,
+        );
     }
 
     fn cut_from_line_start(&mut self) {
         let previous_offset = self.line_buffer.insertion_point();
         self.line_buffer.move_to_line_start();
         let deletion_range = self.line_buffer.insertion_point()..previous_offset;
-        let cut_slice = &self.line_buffer.get_buffer()[deletion_range.clone()];
-        if !cut_slice.is_empty() {
-            self.cut_buffer.set(cut_slice, ClipboardMode::Normal);
-            self.line_buffer.clear_range(deletion_range);
-        }
+        self.maybe_cut(
+            deletion_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Left,
+        );
     }
 
     fn cut_from_end(&mut self) {
-        let cut_slice = &self.line_buffer.get_buffer()[self.line_buffer.insertion_point()..];
-        if !cut_slice.is_empty() {
-            self.cut_buffer.set(cut_slice, ClipboardMode::Normal);
-            self.line_buffer.clear_to_end();
-        }
+        self.maybe_cut(
+            self.line_buffer.insertion_point()..,
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn cut_to_line_end(&mut self) {
-        let cut_slice = &self.line_buffer.get_buffer()
-            [self.line_buffer.insertion_point()..self.line_buffer.find_current_line_end()];
-        if !cut_slice.is_empty() {
-            self.cut_buffer.set(cut_slice, ClipboardMode::Normal);
-            self.line_buffer.clear_to_line_end();
-        }
+        let cut_range =
+            self.line_buffer.insertion_point()..self.line_buffer.find_current_line_end();
+        self.maybe_cut(cut_range, ClipboardMode::Normal, CutDirection::Right);
     }
 
     fn cut_word_left(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let left_index = self.line_buffer.word_left_index();
-        if left_index < insertion_offset {
-            let cut_range = left_index..insertion_offset;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-            self.line_buffer.set_insertion_point(left_index);
-        }
+        let cut_range = left_index..insertion_offset;
+        self.maybe_cut(cut_range.clone(), ClipboardMode::Normal, CutDirection::Left);
     }
 
     fn cut_big_word_left(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let left_index = self.line_buffer.big_word_left_index();
-        if left_index < insertion_offset {
-            let cut_range = left_index..insertion_offset;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-            self.line_buffer.set_insertion_point(left_index);
-        }
+        let cut_range = left_index..insertion_offset;
+        self.maybe_cut(cut_range.clone(), ClipboardMode::Normal, CutDirection::Left);
     }
 
     fn cut_word_right(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let right_index = self.line_buffer.word_right_index();
-        if right_index > insertion_offset {
-            let cut_range = insertion_offset..right_index;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-        }
+        let cut_range = insertion_offset..right_index;
+        self.maybe_cut(
+            cut_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn cut_big_word_right(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let right_index = self.line_buffer.next_whitespace();
-        if right_index > insertion_offset {
-            let cut_range = insertion_offset..right_index;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-        }
+        let cut_range = insertion_offset..right_index;
+        self.maybe_cut(
+            cut_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn cut_word_right_to_next(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let right_index = self.line_buffer.word_right_start_index();
-        if right_index > insertion_offset {
-            let cut_range = insertion_offset..right_index;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-        }
+        let cut_range = insertion_offset..right_index;
+        self.maybe_cut(
+            cut_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn cut_big_word_right_to_next(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let right_index = self.line_buffer.big_word_right_start_index();
-        if right_index > insertion_offset {
-            let cut_range = insertion_offset..right_index;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-        }
+        let cut_range = insertion_offset..right_index;
+        self.maybe_cut(
+            cut_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn cut_char(&mut self) {
         let insertion_offset = self.line_buffer.insertion_point();
         let right_index = self.line_buffer.grapheme_right_index();
-        if right_index > insertion_offset {
-            let cut_range = insertion_offset..right_index;
-            self.cut_buffer.set(
-                &self.line_buffer.get_buffer()[cut_range.clone()],
-                ClipboardMode::Normal,
-            );
-            self.line_buffer.clear_range(cut_range);
-        }
+        let cut_range = insertion_offset..right_index;
+        self.maybe_cut(
+            cut_range.clone(),
+            ClipboardMode::Normal,
+            CutDirection::Right,
+        );
     }
 
     fn insert_cut_buffer_before(&mut self) {
@@ -414,18 +448,9 @@ impl Editor {
             // Saving the section of the string that will be deleted to be
             // stored into the buffer
             let extra = if before_char { 0 } else { c.len_utf8() };
-            let cut_slice =
-                &self.line_buffer.get_buffer()[self.line_buffer.insertion_point()..index + extra];
-
-            if !cut_slice.is_empty() {
-                self.cut_buffer.set(cut_slice, ClipboardMode::Normal);
+            let cut_range = self.line_buffer.insertion_point()..index + extra;
 
-                if before_char {
-                    self.line_buffer.delete_right_before_char(c, current_line);
-                } else {
-                    self.line_buffer.delete_right_until_char(c, current_line);
-                }
-            }
+            self.maybe_cut(cut_range, ClipboardMode::Normal, CutDirection::Right);
         }
     }
 
@@ -434,18 +459,9 @@ impl Editor {
             // Saving the section of the string that will be deleted to be
             // stored into the buffer
             let extra = if before_char { c.len_utf8() } else { 0 };
-            let cut_slice =
-                &self.line_buffer.get_buffer()[index + extra..self.line_buffer.insertion_point()];
-
-            if !cut_slice.is_empty() {
-                self.cut_buffer.set(cut_slice, ClipboardMode::Normal);
+            let cut_range = index + extra..self.line_buffer.insertion_point();
 
-                if before_char {
-                    self.line_buffer.delete_left_before_char(c, current_line);
-                } else {
-                    self.line_buffer.delete_left_until_char(c, current_line);
-                }
-            }
+            self.maybe_cut(cut_range, ClipboardMode::Normal, CutDirection::Left);
         }
     }