feat: impl attribute matching

[huanghongxun]

No description provided.

[LastLeaf]

Is it required to add an extra type parameter?

[TtTRz]

LGTM, thanks for the PR!
But you still need to add some test cases.

[huanghongxun]

Is it required to add an extra type parameter?

A type parameter allows embedder making its own attribute memory layout. Actually I also wishes making StyleQuery::classes generic too.

For example, my embedder setup an Attribute struct with attribute name enumerations to reduce memory footprint.

struct Attr {
   name: AttrName,
   value: TmplNativeData,
}

enum AttrName {
    Class,
    Name,
    EnableFlex,
    ...
}

[TtTRz]

LGTM

[LastLeaf]

Is it required to add an extra type parameter?

A type parameter allows embedder making its own attribute memory layout. Actually I also wishes making StyleQuery::classes generic too.

For example, my embedder setup an Attribute struct with attribute name enumerations to reduce memory footprint.

struct Attr {
   name: AttrName,
   value: TmplNativeData,
}

enum AttrName {
    Class,
    Name,
    EnableFlex,
    ...
}

I think a default implementation is needed for the new type parameter, otherwise it can be weird for clients that does not need attribute matching.

[LastLeaf]

And also, if you wish to use custom layout for node trees, it should better be done through a custom StyleQuery type:

trait StyleQuery {
    type ClassIter: Iterator<Item = (String, Option<NonZeroUsize>)>;
    fn tag_name(&self) -> &str;
    fn classes(&self) -> Self::ClassIter;
    // ...
    fn attribute(&self, name: &str) -> &str;
}