Enum Component

pub enum Component<Impl: SelectorImpl> {
    Combinator(Combinator),
    ExplicitAnyNamespace,
    ExplicitNoNamespace,
    DefaultNamespace(Impl::NamespaceUrl),
    Namespace(Impl::NamespacePrefix, Impl::NamespaceUrl),
    ExplicitUniversalType,
    LocalName(LocalName<Impl>),
    ID(Impl::Identifier),
    Class(Impl::ClassName),
    AttributeInNoNamespaceExists {
        local_name: Impl::LocalName,
        local_name_lower: Impl::LocalName,
    },
    AttributeInNoNamespace {
        local_name: Impl::LocalName,
        operator: AttrSelectorOperator,
        value: Impl::AttrValue,
        case_sensitivity: ParsedCaseSensitivity,
        never_matches: bool,
    },
    AttributeOther(Box<AttrSelectorWithOptionalNamespace<Impl>>),
    Negation(ThinBoxedSlice<Component<Impl>>),
    FirstChild,
    LastChild,
    OnlyChild,
    Root,
    Empty,
    Scope,
    NthChild(i32, i32),
    NthLastChild(i32, i32),
    NthOfType(i32, i32),
    NthLastOfType(i32, i32),
    FirstOfType,
    LastOfType,
    OnlyOfType,
    NonTSPseudoClass(Impl::NonTSPseudoClass),
    Slotted(Selector<Impl>),
    Part(Box<[Impl::PartName]>),
    Host(Option<Selector<Impl>>),
    PseudoElement(Impl::PseudoElement),
}

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

Combinator(Combinator)

ExplicitAnyNamespace

ExplicitNoNamespace

DefaultNamespace(Impl::NamespaceUrl)

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

ExplicitUniversalType

LocalName(LocalName<Impl>)

ID(Impl::Identifier)

Class(Impl::ClassName)

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

never_matches: bool

AttributeOther(Box<AttrSelectorWithOptionalNamespace<Impl>>)

Negation(ThinBoxedSlice<Component<Impl>>)

Pseudo-classes

CSS3 Negation only takes a simple simple selector, but we still need to treat it as a compound selector because it might be a type selector which we represent as a namespace and a localname.

Note: if/when we upgrade this to CSS4, which supports combinators, we need to think about how this should interact with visit_complex_selector, and what the consumers of those APIs should do about the presence of combinators in negation.

FirstChild

LastChild

OnlyChild

Root

Empty

Scope

NthChild(i32, i32)

NthLastChild(i32, i32)

NthOfType(i32, i32)

NthLastOfType(i32, i32)

FirstOfType

LastOfType

OnlyOfType

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::PartName]>)

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

PseudoElement(Impl::PseudoElement)

Implementations

impl<Impl: SelectorImpl> Component<Impl>

pub fn is_combinator(&self) -> bool

Returns true if this is a combinator.

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

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

Trait Implementations

impl<Impl: Clone + SelectorImpl> Clone for Component<Impl>

where Impl::NamespaceUrl: Clone, Impl::NamespacePrefix: Clone, Impl::Identifier: Clone, Impl::ClassName: Clone, Impl::LocalName: Clone, Impl::AttrValue: Clone, Impl::NonTSPseudoClass: Clone, Impl::PartName: 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 for Component<Impl>

where Impl::NamespaceUrl: PartialEq, Impl::NamespacePrefix: PartialEq, Impl::Identifier: PartialEq, Impl::ClassName: PartialEq, Impl::LocalName: PartialEq, Impl::AttrValue: PartialEq, Impl::NonTSPseudoClass: PartialEq, Impl::PartName: PartialEq, Impl::PseudoElement: PartialEq,

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

Tests for self and other values to be equal, and is used by ==.

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

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

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

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

where 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> Visit for Component<Impl>

where Impl::NonTSPseudoClass: Visit<Impl = Impl>,

type Impl = Impl

The type parameter of selector component types.

fn visit<V>(&self, visitor: &mut V) -> bool

where V: SelectorVisitor<Impl = Impl>,

Traverse selector components inside self.

impl<Impl: Eq + SelectorImpl> Eq for Component<Impl>

where Impl::NamespaceUrl: Eq, Impl::NamespacePrefix: Eq, Impl::Identifier: Eq, Impl::ClassName: Eq, Impl::LocalName: Eq, Impl::AttrValue: Eq, Impl::NonTSPseudoClass: Eq, Impl::PartName: Eq, Impl::PseudoElement: Eq,

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