Add cancel buffer (to store cancelled operations.)

src/internal/buffer/generic.cc

@@ -72,21 +72,21 @@ void GenericBuffer::list_history(BEd &ctx) {
   }
 }
 
-HistoryBuffer *GenericBuffer::get_history(uint64_t version) {
+ReadonlyBuffer *GenericBuffer::get_history(uint64_t version) {
   uint64_t current = base_version + undo_stack.size();
   if (version < base_version)
     throw ed_error("History version has been pruned.");
   if (version < current) {
     auto &item = undo_stack[version - base_version];
-    return new HistoryBuffer(name, item.text, item.parse_state);
+    return new ReadonlyBuffer(name, item.text, item.parse_state);
   }
   if (version == current)
-    return new HistoryBuffer(name, root, parse);
+    return new ReadonlyBuffer(name, root, parse);
   uint64_t redo_offset = version - current - 1;
   if (redo_offset >= redo_stack.size())
     throw ed_error("No such history version.");
   auto &item = redo_stack[redo_stack.size() - 1 - redo_offset];
-  return new HistoryBuffer(name, item.text, item.parse_state);
+  return new ReadonlyBuffer(name, item.text, item.parse_state);
 }
 
 void GenericBuffer::snapshot(std::string action_) {

src/internal/parser/address.cc

@@ -188,6 +188,7 @@ void Parser::locator(AddressPromise &addr) {
     token(io::Token::AddressSymbol);
     advance();
     end_token();
+    token(io::Token::Number);
     addr.base = AddressPromise::Current{};
     uint16_t j = 0;
     uint64_t num = 0;

src/internal/ui/text_mode/text_mode.cc

@@ -272,7 +272,7 @@ std::pair<vase::Shard *, bool> TextMode::run_terminal() {
         cursor.col = byte_column(previous.line, wanted);
       } break;
       case io::KeyEvent::SpecialKey::DOWN: {
-        if (cursor.row + 1 >= vase->lines)
+        if (cursor.row >= vase->lines)
           break;
         vase::Iterator current(vase, cursor.row, Direction::Forward);
         if (!current.next())
@@ -294,7 +294,7 @@ std::pair<vase::Shard *, bool> TextMode::run_terminal() {
           if (!it.next())
             throw ed_error("Invalid cursor position.");
           next.col = next_cluster(it.line, cursor.col);
-        } else if (cursor.row + 1 < vase->lines) {
+        } else if (cursor.row < vase->lines) {
           ++next.row;
           next.col = 0;
         } else {