Struct selectors::builder::SelectorBuilder

pub struct SelectorBuilder<Impl: SelectorImpl> {
    components: SmallVec<[Component<Impl>; 32]>,
    last_compound_start: Option<usize>,
}

Top-level SelectorBuilder struct. This should be stack-allocated by the consumer and never moved (because it contains a lot of inline data that would be slow to memmove).

After instantiation, callers may call the push_simple_selector() and push_combinator() methods to append selector data as it is encountered (from left to right). Once the process is complete, callers should invoke build(), which transforms the contents of the SelectorBuilder into a heap- allocated Selector and leaves the builder in a drained state.

Fields

components: SmallVec<[Component<Impl>; 32]>

The entire sequence of components. We make this large because the result of parsing a selector is fed into a new Arc-ed allocation, so any spilled vec would be a wasted allocation. Also, Components are large enough that we don’t have much cache locality benefit from reserving stack space for fewer of them.

last_compound_start: Option<usize>

Implementations

impl<Impl: SelectorImpl> SelectorBuilder<Impl>

pub fn push_simple_selector(&mut self, ss: Component<Impl>)

Pushes a simple selector onto the current compound selector.

pub fn push_combinator(&mut self, c: Combinator)

Completes the current compound selector and starts a new one, delimited by the given combinator.

fn reverse_last_compound(&mut self)

pub fn has_combinators(&self) -> bool

Returns true if combinators have ever been pushed to this builder.

pub fn build( &mut self, parse_relative: ParseRelative, ) -> ThinArc<SpecificityAndFlags, Component<Impl>>

Consumes the builder, producing a Selector.

pub(crate) fn build_with_specificity_and_flags( &mut self, spec: SpecificityAndFlags, parse_relative: ParseRelative, ) -> ThinArc<SpecificityAndFlags, Component<Impl>>

Builds with an explicit SpecificityAndFlags. This is separated from build() so that unit tests can pass an explicit specificity.

Trait Implementations

impl<Impl: Debug + SelectorImpl> Debug for SelectorBuilder<Impl>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<Impl: SelectorImpl> Default for SelectorBuilder<Impl>

fn default() -> Self

Returns the “default value” for a type.

impl<Impl: SelectorImpl> Push<Component<Impl>> for SelectorBuilder<Impl>

fn push(&mut self, value: Component<Impl>)

Push a value into self.