fn patch_children_by_key(
		parent: &mut util::LazyElement,
		old: &mut Vec<Node>,
		mut i: usize,
		new_it: std::iter::Peekable<std::vec::IntoIter<Node>>,
	) -> Result<(), JsValue> {
		// Map old children by key
		let mut old_by_key = HashMap::<u64, Node>::new();
		let mut to_remove = Vec::<Node>::new();
		for ch in old.split_off(i) {
			match ch.key {
				Some(k) => {
					old_by_key.insert(k, ch);
				}
				None => {
					to_remove.push(ch);
				}
			}
		}

		// Insert new HTML into the DOM efficiently in buffered chunks
		old.reserve(new_it.size_hint().0);
		let mut w = util::Appender::new();
		let mut buffered = 0;

		let flush = |w: &mut util::Appender,
		             i: &mut usize,
		             buffered: &mut usize,
		             old: &mut Vec<Node>,
		             parent: &mut util::LazyElement|
		 -> Result<(), JsValue> {
			if *buffered == 0 {
				return Ok(());
			}

			let html = w.dump();
			w.clear();
			if *i == 0 {
				parent.get()?.insert_adjacent_html("afterbegin", &html)?;
			} else {
				old[*i]
					.element
					.get()?
					.insert_adjacent_html("afterend", &html)?;
			}
			*i += *buffered;
			*buffered = 0;

			Ok(())
		};

		for mut new_ch in new_it {
			if let Some(k) = new_ch.key {
				if let Some(mut old_ch) = old_by_key.remove(&k) {
					flush(&mut w, &mut i, &mut buffered, old, parent)?;

					let el = old_ch.element.get()?;
					if i == 0 {
						parent
							.get()?
							.insert_adjacent_element("afterbegin", &el)?;
					} else {
						old[i]
							.element
							.get()?
							.insert_adjacent_element("afterend", &el)?;
					}
					old_ch.patch(new_ch)?;
					old.push(old_ch);
					i += 1;
					continue;
				}
			}
			new_ch.write_html_to(&mut w).map_err(util::cast_error)?;
			old.push(new_ch);
			buffered += 1;
		}
		flush(&mut w, &mut i, &mut buffered, old, parent)?;

		// Remove any unmatched old children
		for mut ch in to_remove
			.into_iter()
			.chain(old_by_key.into_iter().map(|(_, v)| v))
		{
			ch.element.get()?.remove();
		}

		Ok(())
	}
// Match and patch nodes by key, if any
Match and patch nodes by key, if any
Match and patch nodes by key if any
fn patch_children_by_key(
		parent: &mut util::LazyElement,
		old: &mut Vec<Node>,
		mut i: usize,
		new_it: std::iter::Peekable<std::vec::IntoIter<Node>>,
	) -> Result<(), JsValue> {
		// Map old children by key
		let mut old_by_key = HashMap::<u64, Node>::new();
		let mut to_remove = Vec::<Node>::new();
		for ch in old.split_off(i) {
			match ch.key {
				Some(k) => {
					old_by_key.insert(k, ch);
				}
				None => {
					to_remove.push(ch);
				}
			}
		}
		// Insert new HTML into the DOM efficiently in buffered chunks
		old.reserve(new_it.size_hint().0);
		let mut w = util::Appender::new();
		let mut buffered = 0;
		let flush = |w: &mut util::Appender,
		             i: &mut usize,
		             buffered: &mut usize,
		             old: &mut Vec<Node>,
		             parent: &mut util::LazyElement|
		 -> Result<(), JsValue> {
			if *buffered == 0 {
				return Ok(());
			}
			let html = w.dump();
			w.clear();
			if *i == 0 {
				parent.get()?.insert_adjacent_html("afterbegin", &html)?;
			} else {
				old[*i]
					.element
					.get()?
					.insert_adjacent_html("afterend", &html)?;
			}
			*i += *buffered;
			*buffered = 0;
			Ok(())
		};
		for mut new_ch in new_it {
			if let Some(k) = new_ch.key {
				if let Some(mut old_ch) = old_by_key.remove(&k) {
					flush(&mut w, &mut i, &mut buffered, old, parent)?;
					let el = old_ch.element.get()?;
					if i == 0 {
						parent
							.get()?
							.insert_adjacent_element("afterbegin", &el)?;
					} else {
						old[i]
							.element
							.get()?
							.insert_adjacent_element("afterend", &el)?;
					}
					old_ch.patch(new_ch)?;
					old.push(old_ch);
					i += 1;
					continue;
				}
			}
			new_ch.write_html_to(&mut w).map_err(util::cast_error)?;
			old.push(new_ch);
			buffered += 1;
		}
		flush(&mut w, &mut i, &mut buffered, old, parent)?;
		// Remove any unmatched old children
		for mut ch in to_remove
			.into_iter()
			.chain(old_by_key.into_iter().map(|(_, v)| v))
		{
			ch.element.get()?.remove();
		}
		Ok(())
	}
fn patch_children_by_key ( parent : & mut util :: LazyElement , old : & mut Vec < Node > , mut i : usize , new_it : std :: iter :: Peekable < std :: vec :: IntoIter < Node > > , ) -> Result < ( ) , JsValue > { // Map old children by key let mut old_by_key = HashMap :: < u64 , Node > :: new ( ) ; let mut to_remove = Vec :: < Node > :: new ( ) ; for ch in old . split_off ( i ) { match ch . key { Some ( k ) => { old_by_key . insert ( k , ch ) ; } None => { to_remove . push ( ch ) ; } } } // Insert new HTML into the DOM efficiently in buffered chunks old . reserve ( new_it . size_hint ( ) . 0 ) ; let mut w = util :: Appender :: new ( ) ; let mut buffered = 0 ; let flush = | w : & mut util :: Appender , i : & mut usize , buffered : & mut usize , old : & mut Vec < Node > , parent : & mut util :: LazyElement | -> Result < ( ) , JsValue > { if * buffered == 0 { return Ok ( ( ) ) ; } let html = w . dump ( ) ; w . clear ( ) ; if * i == 0 { parent . get ( ) ? . insert_adjacent_html ( " " , & html ) ? ; } else { old [ * i ] . element . get ( ) ? . insert_adjacent_html ( " " , & html ) ? ; } * i += * buffered ; * buffered = 0 ; Ok ( ( ) ) } ; for mut new_ch in new_it { if let Some ( k ) = new_ch . key { if let Some ( mut old_ch ) = old_by_key . remove ( & k ) { flush ( & mut w , & mut i , & mut buffered , old , parent ) ? ; let el = old_ch . element . get ( ) ? ; if i == 0 { parent . get ( ) ? . insert_adjacent_element ( " " , & el ) ? ; } else { old [ i ] . element . get ( ) ? . insert_adjacent_element ( " " , & el ) ? ; } old_ch . patch ( new_ch ) ? ; old . push ( old_ch ) ; i += 1 ; continue ; } } new_ch . write_html_to ( & mut w ) . map_err ( util :: cast_error ) ? ; old . push ( new_ch ) ; buffered += 1 ; } flush ( & mut w , & mut i , & mut buffered , old , parent ) ? ; // Remove any unmatched old children for mut ch in to_remove . into_iter ( ) . chain ( old_by_key . into_iter ( ) . map ( | ( _ , v ) | v ) ) { ch . element . get ( ) ? . remove ( ) ; } Ok ( ( ) ) }
Match and patch nodes by key, if any
Match and patch nodes by key if any
parent
&mut util::LazyElement
old
&mut Vec<Node>
i
usize
new_it
std::iter::Peekable<std::vec::IntoIter<Node>>