Enum selectors::parser::Component

pub enum Component<Impl: SelectorImpl> {
    LocalName(LocalName<Impl>),
    ID(Impl::Identifier),
    Class(Impl::Identifier),
    AttributeInNoNamespaceExists {
        local_name: Impl::LocalName,
        local_name_lower: Impl::LocalName,
    },
    AttributeInNoNamespace {
        local_name: Impl::LocalName,
        operator: AttrSelectorOperator,
        value: Impl::AttrValue,
        case_sensitivity: ParsedCaseSensitivity,
    },
    AttributeOther(Box<AttrSelectorWithOptionalNamespace<Impl>>),
    ExplicitUniversalType,
    ExplicitAnyNamespace,
    ExplicitNoNamespace,
    DefaultNamespace(Impl::NamespaceUrl),
    Namespace(Impl::NamespacePrefix, Impl::NamespaceUrl),
    Negation(Box<[Selector<Impl>]>),
    Root,
    Empty,
    Scope,
    ParentSelector,
    Nth(NthSelectorData),
    NthOf(NthOfSelectorData<Impl>),
    NonTSPseudoClass(Impl::NonTSPseudoClass),
    Slotted(Selector<Impl>),
    Part(Box<[Impl::Identifier]>),
    Host(Option<Selector<Impl>>),
    Where(Box<[Selector<Impl>]>),
    Is(Box<[Selector<Impl>]>),
    Has(Box<[RelativeSelector<Impl>]>),
    PseudoElement(Impl::PseudoElement),
    Combinator(Combinator),
    RelativeSelectorAnchor,
}

A CSS simple selector or combinator. We store both in the same enum for optimal packing and cache performance, see [1].

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1357973

Variants

LocalName(LocalName<Impl>)

ID(Impl::Identifier)

Class(Impl::Identifier)

AttributeInNoNamespaceExists

Fields

local_name: Impl::LocalName

local_name_lower: Impl::LocalName

AttributeInNoNamespace

Fields

local_name: Impl::LocalName

operator: AttrSelectorOperator

value: Impl::AttrValue

case_sensitivity: ParsedCaseSensitivity

AttributeOther(Box<AttrSelectorWithOptionalNamespace<Impl>>)

ExplicitUniversalType

ExplicitAnyNamespace

ExplicitNoNamespace

DefaultNamespace(Impl::NamespaceUrl)

Namespace(Impl::NamespacePrefix, Impl::NamespaceUrl)

Negation(Box<[Selector<Impl>]>)

Pseudo-classes

Root

Empty

Scope

ParentSelector

Nth(NthSelectorData)

NthOf(NthOfSelectorData<Impl>)

NonTSPseudoClass(Impl::NonTSPseudoClass)

Slotted(Selector<Impl>)

The ::slotted() pseudo-element:

https://drafts.csswg.org/css-scoping/#slotted-pseudo

The selector here is a compound selector, that is, no combinators.

NOTE(emilio): This should support a list of selectors, but as of this writing no other browser does, and that allows them to put ::slotted() in the rule hash, so we do that too.

See https://github.com/w3c/csswg-drafts/issues/2158

Part(Box<[Impl::Identifier]>)

The ::part pseudo-element. https://drafts.csswg.org/css-shadow-parts/#part

Host(Option<Selector<Impl>>)

The :host pseudo-class:

https://drafts.csswg.org/css-scoping/#host-selector

NOTE(emilio): This should support a list of selectors, but as of this writing no other browser does, and that allows them to put :host() in the rule hash, so we do that too.

See https://github.com/w3c/csswg-drafts/issues/2158

Where(Box<[Selector<Impl>]>)

The :where pseudo-class.

https://drafts.csswg.org/selectors/#zero-matches

The inner argument is conceptually a SelectorList, but we move the selectors to the heap to keep Component small.

Is(Box<[Selector<Impl>]>)

The :is pseudo-class.

https://drafts.csswg.org/selectors/#matches-pseudo

Same comment as above re. the argument.

Has(Box<[RelativeSelector<Impl>]>)

The :has pseudo-class.

https://drafts.csswg.org/selectors/#has-pseudo

Same comment as above re. the argument.

PseudoElement(Impl::PseudoElement)

An implementation-dependent pseudo-element selector.

Combinator(Combinator)

RelativeSelectorAnchor

Used only for relative selectors, which starts with a combinator (With an implied descendant combinator if not specified).

https://drafts.csswg.org/selectors-4/#typedef-relative-selector

Implementations

impl<Impl: SelectorImpl> Component<Impl>

pub fn is_combinator(&self) -> bool

Returns true if this is a combinator.

pub fn is_host(&self) -> bool

Returns true if this is a :host() selector.

pub fn as_combinator(&self) -> Option<Combinator>

Returns the value as a combinator if applicable, None otherwise.

pub fn maybe_allowed_after_pseudo_element(&self) -> bool

Whether this component is valid after a pseudo-element. Only intended for sanity-checking.

fn matches_for_stateless_pseudo_element(&self) -> bool

Whether a given selector should match for stateless pseudo-elements.

This is a bit subtle: Only selectors that return true in maybe_allowed_after_pseudo_element should end up here, and NonTSPseudoClass never matches (as it is a stateless pseudo after all).

pub fn visit<V>(&self, visitor: &mut V) -> boolwhere V: SelectorVisitor<Impl = Impl>,

Trait Implementations

impl<Impl: Clone + SelectorImpl> Clone for Component<Impl>where Impl::Identifier: Clone, Impl::LocalName: Clone, Impl::AttrValue: Clone, Impl::NamespaceUrl: Clone, Impl::NamespacePrefix: Clone, Impl::NonTSPseudoClass: Clone, Impl::PseudoElement: Clone,

fn clone(&self) -> Component<Impl>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<Impl: SelectorImpl> Debug for Component<Impl>

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

Formats the value using the given formatter.

impl<Impl: PartialEq + SelectorImpl> PartialEq<Component<Impl>> for Component<Impl>where Impl::Identifier: PartialEq, Impl::LocalName: PartialEq, Impl::AttrValue: PartialEq, Impl::NamespaceUrl: PartialEq, Impl::NamespacePrefix: PartialEq, Impl::NonTSPseudoClass: PartialEq, Impl::PseudoElement: PartialEq,

fn eq(&self, other: &Component<Impl>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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

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

Push a value into self.

impl<Impl: SelectorImpl> ToCss for Component<Impl>

fn to_css<W>(&self, dest: &mut W) -> Resultwhere W: Write,

Serialize self in CSS syntax, writing to dest.

fn to_css_string(&self) -> String

Serialize self in CSS syntax and return a string.

impl<Impl: SelectorImpl> ToShmem for Component<Impl>where Impl::Identifier: ToShmem, Impl::LocalName: ToShmem, Impl::AttrValue: ToShmem, Impl::NamespaceUrl: ToShmem, Impl::NamespacePrefix: ToShmem, Impl::NonTSPseudoClass: ToShmem, Box<[Impl::Identifier]>: ToShmem, Impl::PseudoElement: ToShmem,

fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> Result<Self>

Clones this value into a form suitable for writing into a SharedMemoryBuilder.

impl<Impl: Eq + SelectorImpl> Eq for Component<Impl>where Impl::Identifier: Eq, Impl::LocalName: Eq, Impl::AttrValue: Eq, Impl::NamespaceUrl: Eq, Impl::NamespacePrefix: Eq, Impl::NonTSPseudoClass: Eq, Impl::PseudoElement: Eq,

impl<Impl: SelectorImpl> StructuralEq for Component<Impl>

impl<Impl: SelectorImpl> StructuralPartialEq for Component<Impl>