Simon Wülker 9193b1d310 xpath: Enforce tree order in node sets during evaluation (#40451) ...

This change adds `NodeSet`, which is more or less a `Vec<Node>` that
knows whether it is sorted, and can sort itself if it isn't. This allows
us to efficiently enforce tree order in intermediary node sets that
occur during evaluation.

Notably, in many cases it is not necessary to sort at all, because all
location step expressions yield node sets that are either already sorted
(`Axis::DescendantOrSelf` for example), or that are in inverse tree
order (`Axis::PrecedingSiblings` for example).

There's still optimization work left to be done. When merging two node
sets that are already sorted then we could use merge sort instead of
appending one to the other and naively sorting. But I suspect that the
sorting algorithm used by the standard library is already well tuned to
handle such cases...

Testing: This change adds a web platform test
Fixes https://github.com/servo/servo/issues/40435

---------

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

2025-11-06 12:24:07 +00:00

..

src

xpath: Enforce tree order in node sets during evaluation (#40451)

2025-11-06 12:24:07 +00:00

Cargo.toml

xpath: Replace nom with hand-written parsing rules (#39977)

2025-10-25 03:23:02 +00:00