Struct ParseTreePattern 

pub struct ParseTreePattern { /* private fields */ }

A pattern like <ID> = <expr>; compiled to a reusable tree.

Created by ParseTreePatternMatcher::compile or a generated parser’s compile_parse_tree_pattern. Match a subject tree with Self::match_tree (full result) or Self::matches (boolean).

Implementations

impl ParseTreePattern

pub fn pattern(&self) -> &str

The tree-pattern source string this was compiled from.

pub const fn pattern_rule_index(&self) -> usize

The parser rule index that roots the pattern.

pub fn pattern_tree(&self) -> Node<'_>

The compiled pattern as a parse tree, with tags present as terminal leaves (a rule tag is a rule node whose single child carries the imaginary bypass token).

Mirrors ANTLR’s ParseTreePattern.getPatternTree; useful for inspecting why a pattern that compiled does not match a subject — pattern_tree().text() renders the tag placeholders inline.

pub fn match_tree<'subject>( &self, tree: Node<'subject>, ) -> ParseTreeMatch<'subject>

Matches tree against this pattern, returning the full result including bound labels and the first mismatched node (if any).

pub fn matches(&self, tree: Node<'_>) -> bool

Returns whether tree matches this pattern.

pub fn find_all<'subject, R>( &self, tree: Node<'subject>, xpath: &str, recognizer: &R, ) -> Result<Vec<ParseTreeMatch<'subject>>, XPathError>

where R: Recognizer + ?Sized,

Finds nodes under tree with an XPath expression, then returns the successful matches of this pattern against those subtrees.

Mirrors ANTLR’s ParseTreePattern.findAll: unsuccessful matches are omitted, whatever the reason for the failure. recognizer resolves the rule and token names in xpath, exactly as in XPath::find_all.

Errors

Returns XPathError when xpath is not a valid parse-tree path expression.

Trait Implementations

impl Debug for ParseTreePattern

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

Formats the value using the given formatter.