Struct QueryBuilder 

pub struct QueryBuilder<'query> {
    pub states: Vec<Transition<'query>>,
    pub selection: Vec<QuerySection<'query>>,
}

An in-progress query being assembled via a builder pattern.

You typically don’t construct a QueryBuilder directly; instead, start with Query::all or Query::first and then chain further selectors with .all(), .first(), or .then(). Finalise with .build() to produce a Query.

Example

use scah::{Query, Save};

let query = Query::all("main > section", Save::all())
    .then(|ctx| [
        ctx.all("> a[href]", Save::all()),
        ctx.all("div a",    Save::only_text_content()),
    ])
    .build();

Fields

states: Vec<Transition<'query>>

Internal automaton transitions (compiled selector segments).

selection: Vec<QuerySection<'query>>

Internal ordered list of query sections.

Implementations

impl<'query> QueryBuilder<'query>

pub fn all(self, query: &'query str, save: Save) -> Self

Append a child selector that matches all occurrences.

The new selector is scoped to elements that already matched the previous selector in the chain.

pub fn first(self, query: &'query str, save: Save) -> Self

Append a child selector that matches only the first occurrence.

Enables early-exit optimisation for this branch of the query tree.

pub fn append(&mut self, parent: usize, other: Self)

pub fn then<F, I>(self, func: F) -> Self

where F: FnOnce(QueryFactory) -> I, I: IntoIterator<Item = Self>,

Branch into multiple child queries using a closure.

The closure receives a QueryFactory that can create new sub-queries. Each sub-query is scoped to run only within elements matched by the current (most recently added) selector.

This is the key mechanism for structured querying; extracting hierarchical data relationships in a single streaming pass.

Example

use scah::{Query, Save};

let query = Query::all("article", Save::none())
    .then(|article| [
        article.first("h1",      Save::only_text_content()),
        article.all("a[href]",   Save::all()),
    ])
    .build();

impl<'query> QueryBuilder<'query>

pub fn build(self) -> Query<'query>

Finalise the builder and produce a compiled Query.

This computes early-exit optimisation metadata and converts the internal vectors into boxed slices. After calling build, pass the resulting Query to parse.

Trait Implementations

impl<'query> Clone for QueryBuilder<'query>

fn clone(&self) -> QueryBuilder<'query>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'query> Debug for QueryBuilder<'query>

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

Formats the value using the given formatter.