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#![doc = include_str!("../README.md")]
//! ## Usage
//! - Lua patterns can be parsed to a tree with [`parse`].
//! - Parsed patterns can be converted to regex strings with [`try_to_regex`].
//!
//! For example:
//! ```
//! use lua_pattern::{Class, PatternObject};
//!
//! let tree = lua_pattern::parse("%l").unwrap();
//! assert_eq!(tree, [PatternObject::Class(Class::Lowercase)]);
//! #[cfg(feature = "to-regex")]
//! assert_eq!(lua_pattern::try_to_regex(&tree, false, false).unwrap(), "[a-z]");
//! ```
#![cfg_attr(
feature = "docs",
cfg_attr(doc, doc = ::document_features::document_features!(feature_label = r#"<span class="stab portability"><code>{feature}</code></span>"#))
)]
#![cfg_attr(all(doc, CHANNEL_NIGHTLY), feature(doc_auto_cfg))]
#![warn(rust_2018_idioms)]
#![deny(missing_docs)]
mod error;
mod lexer;
mod parser;
#[cfg(feature = "to-regex")]
mod to_regex;
use std::fmt::{self, Display, Formatter};
pub use error::*;
use lexer::Lexer;
use parser::Parser;
#[cfg(feature = "to-regex")]
pub use to_regex::*;
///////////////
// Functions //
///////////////
/// Parse the given input string as a Lua pattern.
///
/// # Returns
/// This function returns a vector of [`PatternObject`]s if parsing was successful, or an [`Error`]
/// if the pattern could not be parsed.
///
/// # Errors
/// To see the possible errors, have a look at [`Error`].
pub fn parse(pattern: impl AsRef<str>) -> Result<Pattern> {
Parser::parse(Lexer::lex(pattern.as_ref())?)
}
///////////
// Types //
///////////
/// A list of [`PatternObject`]s, representing an entire Lua pattern.
pub type Pattern = Vec<PatternObject>;
/// A single object of a Lua pattern.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PatternObject {
/// Match any character (`.`).
Any,
/// Match the start of the string (`^`).
Start,
/// Match the end of the string (`$`).
End,
/// A sequence of characters to match literally (eg. `Hello, World!`).
String(String),
/// A [`PatternObject`] followed by a [`Quantifier`] (eg. `a?`, `.*`).
Quantifier(Quantifier, Box<PatternObject>),
/// An escaped character to match literally (eg. `%%`).
Escaped(char),
/// A [character class](Class) (eg. `%w`, `%L`).
Class(Class),
/// A reference to a previous capture group (eg. `%1`).
CaptureRef(u8),
/// A balanced pattern (eg. `%bxy`). Matches all characters starting at `x` until the
/// corresponding `y`.
Balanced(char, char),
/// A frontier pattern (eg. `%f[a-z]`). Matches if the following character matches the set and
/// the previous character does not match the set. The `bool` indicated whether the set is
/// inverted.
Frontier(bool, Vec<SetPatternObject>),
/// A capture group with a numeric ID and the contained [`Pattern`] (eg. `(a)`).
Capture(u8, Pattern),
/// A set of [`SetPatternObject`]s (eg. `[a-z_%u]`, `[^a-z_%u]`), the `bool` specifies whether
/// the set is inverted. If the set is _not_ inverted, it matches if any of the contained
/// entries matches. Otherwise, it matches if none of the contained entries match.
Set(bool, Vec<SetPatternObject>),
}
/// An entry of a [set](PatternObject::Set).
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum SetPatternObject {
/// A character to match literally (eg. `a`).
Char(char),
/// An escaped character to match literally (eg. `%%`, `%]`).
Escaped(char),
/// A range of characters (eg. `a-z`). Matches if any character in the range matches.
Range(char, char),
/// A [character class](Class) (eg. `%w`, `%L`).
Class(Class),
}
/// A quantifier, specifying the amount of times the leading [`PatternObject`] can occur.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Quantifier {
/// Allow zero or more occurrences, taking the longest matching sequence (`*`).
ZeroOrMore,
/// Allow one or more occurrences, taking the longest matching sequence (`+`).
OneOrMore,
/// Allow zero or more occurrences, taking the shortest matching sequence (`-`).
ZeroOrMoreLazy,
/// Allow zero or one occurrences (`?`).
ZeroOrOne,
}
/// A character class, matching any character contained in the class.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Class {
/// Matches any letter; equivalent to `[a-zA-Z]` (`%a`).
Letters,
/// Matches any control character; equivalent to `[\0-\31]` (`%c`).
Controls,
/// Matches any digit; equivalent to `[0-9]` (`%d`).
Digits,
/// Matches any printable character except space; equivalent to `[\33-\126]` (`%g`).
Printable,
/// Matches any lowercase letter; equivalent to `[a-z]` (`%l`).
Lowercase,
/// Matches any punctuation character; equivalent to ``[!"#$%&'()*+,-./[\%]^_`{|}~]`` (`%p`).
Punctuations,
/// Matches any whitespace character; equivalent to `[ \t\n\v\f\r]` (`%s`).
Spaces,
/// Matches any uppercase letter; equivalent to `[A-Z]` (`%u`).
Uppercase,
/// Matches any alphanumeric character (digit or letter); equivalent to `[a-zA-Z0-9]` (`%w`).
Alphanumerics,
/// Matches any hexadecimal digit; equivalent to `[0-9a-fA-F]` (`%x`).
Hexadecimals,
/// Matches the NULL character / `0` byte; equivalent to `\0` (`%z`).
ZeroByte,
/// Matches any character, **except** all letters; equivalent to `[^a-zA-Z]` (`%A`).
NotLetters,
/// Matches any character, **except** all control characters; equivalent to `[^\0-\31]` (`%C`).
NotControls,
/// Matches any character, **except** all digits; equivalent to `[^0-9]` (`%D`).
NotDigits,
/// Matches any character, **except** all printable characters, but including space; equivalent
/// to `[^\33-\126]` (`%G`).
NotPrintable,
/// Matches any character, **except** all lowercase letters; equivalent to `[^a-z]` (`%L`).
NotLowercase,
/// Matches any character, **except** all punctuation characters; equivalent to
/// ``[^!"#$%&'()*+,-./[\%]^_`{|}~]`` (`%P`).
NotPunctuations,
/// Matches any character, **except** all whitespace characters; equivalent to `[^ \t\n\v\f\r]`
/// (`%S`).
NotSpaces,
/// Matches any character, **except** all uppercase letters; equivalent to `[^A-Z]` (`%U`).
NotUppercase,
/// Matches any character, **except** all alphanumeric characters (digits and letters);
/// equivalent to `[^a-zA-Z0-9]` (`%W`).
NotAlphanumerics,
/// Matches any character, **except** all hexadecimal digits; equivalent to `[^0-9a-fA-F]`
/// (`%X`).
NotHexadecimals,
/// Matches the character, **except** the NULL character / `0` byte; equivalent to `[^\0]`
/// (`%Z`).
NotZeroByte,
}
/// A token as used by the internal lexer. Exposed to the public API for use in [`Error`]s.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Token {
/// `^`
Start,
/// `$`
End,
/// `.`
Any,
/// `*`
ZeroOrMore,
/// `+`
OneOrMore,
/// `-`
ZeroOrMoreLazy,
/// `?`
ZeroOrOne,
/// `^` in a set
Inverse,
/// `(`
LParen,
/// `)`
RParen,
/// `[`
LBrack,
/// `]`
RBrack,
/// A literal character
Char(char),
/// An escaped character
Escaped(char),
/// A character class
Class(Class),
/// A reference to a previous capture group
CaptureRef(u8),
/// `%b`
Balanced(char, char),
/// `%f`
Frontier,
/// End of file
Eof,
}
///////////////////////////
// Trait implementations //
///////////////////////////
impl TryFrom<Token> for Quantifier {
type Error = ();
fn try_from(value: Token) -> std::result::Result<Self, Self::Error> {
match value {
Token::ZeroOrMore => Ok(Self::ZeroOrMore),
Token::OneOrMore => Ok(Self::OneOrMore),
Token::ZeroOrMoreLazy => Ok(Self::ZeroOrMoreLazy),
Token::ZeroOrOne => Ok(Self::ZeroOrOne),
_ => Err(()),
}
}
}
impl TryFrom<char> for Class {
type Error = ();
fn try_from(value: char) -> std::result::Result<Self, Self::Error> {
match value {
'a' => Ok(Self::Letters),
'c' => Ok(Self::Controls),
'd' => Ok(Self::Digits),
'g' => Ok(Self::Printable),
'l' => Ok(Self::Lowercase),
'p' => Ok(Self::Punctuations),
's' => Ok(Self::Spaces),
'u' => Ok(Self::Uppercase),
'w' => Ok(Self::Alphanumerics),
'x' => Ok(Self::Hexadecimals),
'z' => Ok(Self::ZeroByte),
'A' => Ok(Self::NotLetters),
'C' => Ok(Self::NotControls),
'D' => Ok(Self::NotDigits),
'G' => Ok(Self::NotPrintable),
'L' => Ok(Self::NotLowercase),
'P' => Ok(Self::NotPunctuations),
'S' => Ok(Self::NotSpaces),
'U' => Ok(Self::NotUppercase),
'W' => Ok(Self::NotAlphanumerics),
'X' => Ok(Self::NotHexadecimals),
'Z' => Ok(Self::NotZeroByte),
_ => Err(()),
}
}
}
impl Display for Token {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Token::Start => write!(f, "^"),
Token::End => write!(f, "$"),
Token::Any => write!(f, "."),
Token::ZeroOrMore => write!(f, "*"),
Token::OneOrMore => write!(f, "+"),
Token::ZeroOrMoreLazy => write!(f, "-"),
Token::ZeroOrOne => write!(f, "?"),
Token::Inverse => write!(f, "^"),
Token::LParen => write!(f, "("),
Token::RParen => write!(f, ")"),
Token::LBrack => write!(f, "["),
Token::RBrack => write!(f, "]"),
Token::Char(char) => write!(f, "{char}"),
Token::Escaped(char) => write!(f, "%{char}"),
Token::Class(class) => write!(f, "{class}"),
Token::CaptureRef(id) => write!(f, "%{id}"),
Token::Balanced(open, close) => write!(f, "%b{open}{close}"),
Token::Frontier => write!(f, "%f"),
Token::Eof => write!(f, "end of file"),
}
}
}
impl Display for Class {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
Class::Letters => write!(f, "%a"),
Class::Controls => write!(f, "%c"),
Class::Digits => write!(f, "%d"),
Class::Printable => write!(f, "%g"),
Class::Lowercase => write!(f, "%l"),
Class::Punctuations => write!(f, "%p"),
Class::Spaces => write!(f, "%s"),
Class::Uppercase => write!(f, "%u"),
Class::Alphanumerics => write!(f, "%w"),
Class::Hexadecimals => write!(f, "%x"),
Class::ZeroByte => write!(f, "%z"),
Class::NotLetters => write!(f, "%A"),
Class::NotControls => write!(f, "%C"),
Class::NotDigits => write!(f, "%D"),
Class::NotPrintable => write!(f, "%G"),
Class::NotLowercase => write!(f, "%L"),
Class::NotPunctuations => write!(f, "%P"),
Class::NotSpaces => write!(f, "%S"),
Class::NotUppercase => write!(f, "%U"),
Class::NotAlphanumerics => write!(f, "%W"),
Class::NotHexadecimals => write!(f, "%X"),
Class::NotZeroByte => write!(f, "%Z"),
}
}
}