Crate derivre 

A derivative-based regular expression engine.

The primary entry point is Regex for simple patterns, or RegexBuilder for constructing regexes programmatically from RegexAst trees.

Anchored matching. The engine only checks whether a regex matches the input from the beginning — there is an implied \A anchor. It does not search for matches within the input.

Lookahead. A single look-ahead at the end of the regex is supported via the A(?P<stop>B) syntax. See Regex::lookahead_len for details.

References

• Regular-expression derivatives reexamined (Owens et al.)
• Derivative Based Nonbacktracking Real-World Regex Matching with Backtracking Semantics
• Derivative Based Extended Regular Expression Matching Supporting Intersection, Complement and Lookarounds

Modules

raw

Low-level building blocks for advanced use cases.

Structs

AlphabetInfo

Information about the compressed byte alphabet used by a Regex.

ExprRef

An opaque handle that references an expression node inside an ExprSet.

JsonQuoteOptions

Options controlling how a regex is transformed to match inside a JSON-quoted string (e.g., converting literal newlines to \\n).

Regex

A compiled regular expression backed by a lazily-constructed DFA.

RegexBuilder

A builder for constructing Regex instances from RegexAst trees.

StateID

An opaque identifier for a state in the lazily-constructed DFA.

Enums

NextByte

Describes the “next byte” information for a given ExprRef or StateID.

RegexAst

An AST node representing a regex pattern for use with RegexBuilder.

Constants

VERSION

Functions

map_ast

Type Aliases

HashMap

A std::collections::HashMap using the crate’s RandomState hasher.

HashSet

A std::collections::HashSet using the crate’s RandomState hasher.

RandomState

The hash random state used throughout the crate.