Alow manipulating Selector parts from consumer code

selectors/parser.rs

@@ -724,6 +724,47 @@ impl<'i, Impl: SelectorImpl<'i>> Selector<'i, Impl> {
  self.1.insert(index, component);
  }
 
+ /// Inserts a [`Component`] to an arbitrary index in the internal components Vec.
+ ///
+ /// An order in which components are stored is right-to-left (see [`Selector::iter_raw_match_order()`])
+ #[inline]
+ pub fn insert_raw(&mut self, index: usize, component: Component<'i, Impl>) {
+ self.1.insert(index, component)
+ }
+
+ /// Inserts multiple [`Component`]s to an arbitrary index in the internal components Vec.
+ ///
+ /// An order in which components are stored is right-to-left (see [`Selector::iter_raw_match_order()`])
+ #[inline]
+ pub fn insert_raw_multiple(&mut self, index: usize, mut components: Vec<Component<'i, Impl>>) {
+ if index > self.1.len() {
+ return;
+ }
+
+ let old_len = self.1.len();
+ let mut old = std::mem::replace(&mut self.1, Vec::with_capacity(old_len + components.len()));
+
+ // Fast track: insert at index 0 is the same as Vec::append
+ if index == 0 {
+ self.1.append(&mut components);
+ self.1.append(&mut old);
+ return;
+ }
+
+ // Manually move the first `index` elements
+ let mut old_iter = old.into_iter();
+ for _ in 0..index {
+ let Some(old_component) = old_iter.next() else {
+ unreachable!("index is never greater than selector len")
+ };
+
+ self.1.push(old_component)
+ }
+
+ self.1.append(&mut components);
+ self.1.extend(old_iter);
+ }
+
  #[inline]
  pub fn parts(&self) -> Option<&[Impl::Identifier]> {
  if !self.is_part() {