Module selectors::builder

Helper module to build up a selector safely and efficiently.

Our selector representation is designed to optimize matching, and has several requirements:

• All simple selectors and combinators are stored inline in the same buffer as Component instances.
• We store the top-level compound selectors from right to left, i.e. in matching order.
• We store the simple selectors for each combinator from left to right, so that we match the cheaper simple selectors first.

For example, the selector:

.bar:hover > .baz:nth-child(2) + .qux

Gets stored as:

[.qux, + , .baz, :nth-child(2), > , .bar, :hover]

Meeting all these constraints without extra memmove traffic during parsing is non-trivial. This module encapsulates those details and presents an easy-to-use API for the parser.

Structs

• ExactChain 🔒
• SelectorBuilder
  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).
• SelectorFlags 🔒
  Flags that indicate at which point of parsing a selector are we.
• Specificity 🔒
• SpecificityAndFlags

Constants

• MAX_10BIT 🔒

Functions

• complex_selector_specificity_and_flags 🔒
• relative_selector_list_specificity_and_flags 🔒
• selector_list_specificity_and_flags 🔒
  Finds the maximum specificity of elements in the list and returns it.
• specificity_and_flags 🔒