[webkit-reviews] review requested: [Bug 6248] CSS3: implement nth-* selectors (Acid3 bug) : [Attachment 18969] Latest patch

[bugzilla-daemon at webkit.org]

Dave Hyatt <hyatt at apple.com> has asked	for review:
Bug 6248: CSS3: implement nth-* selectors (Acid3 bug)
http://bugs.webkit.org/show_bug.cgi?id=6248

Attachment 18969: Latest patch
http://bugs.webkit.org/attachment.cgi?id=18969&action=edit

------- Additional Comments from Dave Hyatt <hyatt at apple.com>
I have made the following changes from the previous patch:

(1) Use setChildrenAffectedByPositionalRules so that all the selectors work
dynamically when the DOM changes.
(2) Annotated the selectors that are slow with FIXMEs.
(3) Fixed a bug in parseNth that caused the b values to be incorrect in some
cases (e.g., n+2).
(4) Added support for nth-last-child and nth-last-of-type.
(5) Cache m_childIndex in RenderStyles to make nth-child fast.

My goal here is to really make the common selectors (first-child, empty,
only-child, last-child, nth-child) fast.  The -of-type selectors and the
nth-last-child selector remain very slow, but they won't be used in practice I
expect.