std::regex

Status: experimental

Compiled regular expressions (Rust regex crate syntax; no backreferences or look-around).

Unicode behavior

Unicode mode is enabled by default. UTF-8 literals, ., \w, \s, Unicode property classes such as \p{Greek}, case-insensitive matching, captures, split, and replacement operate on Unicode scalar values.

Regex does not normalize text and does not treat an extended grapheme cluster as one character. Normalize input explicitly when canonical equivalence is required. find and find_all return UTF-8 byte offsets, matching the underlying Rust regex API, while the matched text remains valid UTF-8.

API details and source

The implementation source contains the complete declarations and implementation notes. The table below lists canonical Gossamer call signatures; every item name links directly to its implementation file.

Item	Canonical signature or declaration	Description
Pattern	type Pattern	Compiled pattern handle returned by compile.
captures	fn captures(pattern: regex::Pattern, text: String) -> Option<Vec<Option<String>>>	Returns capture groups for the first match; index 0 is the full match.
captures_all	fn captures_all(pattern: regex::Pattern, text: String) -> Vec<Vec<Option<String>>>	Returns capture groups for every match in the text.
compile	fn compile(pattern: String) -> Result<regex::Pattern, errors::Error>	Parses a pattern into a reusable Pattern or returns an Err.
find	fn find(pattern: regex::Pattern, text: String) -> Option<(i64, i64, String)>	Returns the first match as (start, end, text), or None.
find_all	fn find_all(pattern: regex::Pattern, text: String) -> Vec<(i64, i64, String)>	Returns every non-overlapping match as (start, end, text).
is_match	fn is_match(pattern: regex::Pattern, text: String) -> bool	Returns whether the pattern matches anywhere in the text.
replace	fn replace(pattern: regex::Pattern, text: String, replacement: String) -> String	Replaces the first match with the given replacement (supports $N).
replace_all	fn replace_all(pattern: regex::Pattern, text: String, replacement: String) -> String	Replaces every non-overlapping match.
split	fn split(pattern: regex::Pattern, text: String) -> Vec<String>	Splits the text on every pattern match.