Struct RDFRegex 

pub struct RDFRegex { /* private fields */ }

A regular expression for RDF and SPARQL pattern matching.

This type wraps the Rust Regex type with SPARQL/XPath-compatible flag handling. It stores both the compiled regex and the original pattern with flags for display and debugging purposes.

Implementations

impl RDFRegex

pub fn new(pattern: &str, flags: Option<&str>) -> Result<Self, RDFRegexError>

Creates a new regular expression with SPARQL-compatible flags.

This constructor builds a regex following the XPath/SPARQL flag semantics, which differ slightly from standard Rust regex flags. The implementation is inspired by the Oxigraph SPARQL engine (https://github.com/oxigraph/oxigraph/blob/main/lib/spareval/src/eval.rs).

Arguments

• pattern - The regular expression pattern string
• flags - Optional string containing flag characters (see below)

Supported Flags

Following the XPath specification:

• s (dot-all): Makes . match any character including newlines
• m (multi-line): Makes ^ and $ match line boundaries, not just string boundaries
• i (case-insensitive): Performs case-insensitive matching
• x (ignore whitespace): Ignores unescaped whitespace and enables comments with #
• q (quote/literal): Treats the entire pattern as a literal string (escapes special characters)

Flags can be combined, e.g., "im" for case-insensitive multi-line matching.

Size Limits

The compiled regex is limited to [REGEX_SIZE_LIMIT] bytes. Patterns exceeding this limit will fail with an error.

Errors

Returns an error if:

• The pattern syntax is invalid (e.g., unbalanced parentheses, invalid escape sequences)
• An unsupported flag character is provided
• The compiled regex exceeds the size limit

pub fn is_match(&self, text: &str) -> bool

Tests whether the regex matches the given text.

Returns true if the pattern matches any part of the input string, following standard regex semantics (not anchored by default).

Arguments

• text - The string to test against the pattern

pub fn flags(&self) -> Option<&str>

Returns the flags used to create this regex, if any.

pub fn source(&self) -> &str

Returns the source pattern string.

For patterns created with the q (quote) flag, this returns the escaped version of the original pattern.

Trait Implementations

impl Clone for RDFRegex

fn clone(&self) -> RDFRegex

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RDFRegex

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

Formats the value using the given formatter.

impl Display for RDFRegex

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

Formats the regex in a compact notation showing pattern and flags.

Output format

• /pattern/flags