On Thu, Nov 3, 2016 at 1:30 PM, Simon Sapin <simon.sa...@exyr.org> wrote:
> On 03/11/16 21:02, Boris Zbarsky wrote: > >> On 11/3/16 3:17 PM, Simon Sapin wrote: >> >>> An important aspect is that atoms with different static sets are >>> different Rust types. >>> >> >> Just to check that I understand correctly... >> >> Are element names atoms? Which static set do they come from? >> Presumably the html5ever one? >> > > Yes. Previously Servo had a single Atom type that was used, among other > things, for element names. > > Now there is html5ever_atoms::LocalName (which is a type alias for > string_cache::Atom<html5ever_atoms::LocalNameStaticSet>), used for > element and content attribute names. > > > When parsing CSS selectors, are tag name selectors atomized? Which >> static set is used for that? >> > > Yes. Types from the selectors crate are generic, with a trait that has > associated types for the string types of various components. > > Servo defines: > > type AttrValue = std::string::String; > type Identifier = servo_atoms::Atom; > type ClassName = servo_atoms::Atom; > type LocalName = html5ever_atoms::LocalName; > type NamespacePrefix = html5ever_atoms::Prefix; > > Stylo defines: > > type AttrValue = gecko_string_cache::Atom; > type Identifier = gecko_string_cache::Atom; > type ClassName = gecko_string_cache::Atom; > type LocalName = gecko_string_cache::Atom; > type NamespacePrefix = gecko_string_cache::Atom; > > gecko_string_cache::Atom wraps *mut nsIAtom. > > (I don’t know if there’s a reason for the discrepancy: interning attribute > values in selectors in Stylo but not Servo. We can change it.) > I did this for stylo because those attribute values needed to be passed across the FFI boundaries, and passing atoms is much cheaper than passing strings. There was some mechanical reason I couldn't do it easily for Servo, but I don't remember what it was. > > -- > Simon Sapin > > _______________________________________________ > dev-servo mailing list > dev-servo@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-servo > _______________________________________________ dev-servo mailing list dev-servo@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-servo
