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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/rust/regex-syntax/src/ast/parse.rs
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/regex-syntax/src/ast/parse.rs')
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diff --git a/third_party/rust/regex-syntax/src/ast/parse.rs b/third_party/rust/regex-syntax/src/ast/parse.rs
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+/*!
+This module provides a regular expression parser.
+*/
+
+use std::borrow::Borrow;
+use std::cell::{Cell, RefCell};
+use std::mem;
+use std::result;
+
+use crate::ast::{self, Ast, Position, Span};
+use crate::either::Either;
+
+use crate::is_meta_character;
+
+type Result<T> = result::Result<T, ast::Error>;
+
+/// A primitive is an expression with no sub-expressions. This includes
+/// literals, assertions and non-set character classes. This representation
+/// is used as intermediate state in the parser.
+///
+/// This does not include ASCII character classes, since they can only appear
+/// within a set character class.
+#[derive(Clone, Debug, Eq, PartialEq)]
+enum Primitive {
+ Literal(ast::Literal),
+ Assertion(ast::Assertion),
+ Dot(Span),
+ Perl(ast::ClassPerl),
+ Unicode(ast::ClassUnicode),
+}
+
+impl Primitive {
+ /// Return the span of this primitive.
+ fn span(&self) -> &Span {
+ match *self {
+ Primitive::Literal(ref x) => &x.span,
+ Primitive::Assertion(ref x) => &x.span,
+ Primitive::Dot(ref span) => span,
+ Primitive::Perl(ref x) => &x.span,
+ Primitive::Unicode(ref x) => &x.span,
+ }
+ }
+
+ /// Convert this primitive into a proper AST.
+ fn into_ast(self) -> Ast {
+ match self {
+ Primitive::Literal(lit) => Ast::Literal(lit),
+ Primitive::Assertion(assert) => Ast::Assertion(assert),
+ Primitive::Dot(span) => Ast::Dot(span),
+ Primitive::Perl(cls) => Ast::Class(ast::Class::Perl(cls)),
+ Primitive::Unicode(cls) => Ast::Class(ast::Class::Unicode(cls)),
+ }
+ }
+
+ /// Convert this primitive into an item in a character class.
+ ///
+ /// If this primitive is not a legal item (i.e., an assertion or a dot),
+ /// then return an error.
+ fn into_class_set_item<P: Borrow<Parser>>(
+ self,
+ p: &ParserI<'_, P>,
+ ) -> Result<ast::ClassSetItem> {
+ use self::Primitive::*;
+ use crate::ast::ClassSetItem;
+
+ match self {
+ Literal(lit) => Ok(ClassSetItem::Literal(lit)),
+ Perl(cls) => Ok(ClassSetItem::Perl(cls)),
+ Unicode(cls) => Ok(ClassSetItem::Unicode(cls)),
+ x => Err(p.error(*x.span(), ast::ErrorKind::ClassEscapeInvalid)),
+ }
+ }
+
+ /// Convert this primitive into a literal in a character class. In
+ /// particular, literals are the only valid items that can appear in
+ /// ranges.
+ ///
+ /// If this primitive is not a legal item (i.e., a class, assertion or a
+ /// dot), then return an error.
+ fn into_class_literal<P: Borrow<Parser>>(
+ self,
+ p: &ParserI<'_, P>,
+ ) -> Result<ast::Literal> {
+ use self::Primitive::*;
+
+ match self {
+ Literal(lit) => Ok(lit),
+ x => Err(p.error(*x.span(), ast::ErrorKind::ClassRangeLiteral)),
+ }
+ }
+}
+
+/// Returns true if the given character is a hexadecimal digit.
+fn is_hex(c: char) -> bool {
+ ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
+}
+
+/// Returns true if the given character is a valid in a capture group name.
+///
+/// If `first` is true, then `c` is treated as the first character in the
+/// group name (which must be alphabetic or underscore).
+fn is_capture_char(c: char, first: bool) -> bool {
+ c == '_'
+ || (!first
+ && (('0' <= c && c <= '9') || c == '.' || c == '[' || c == ']'))
+ || ('A' <= c && c <= 'Z')
+ || ('a' <= c && c <= 'z')
+}
+
+/// A builder for a regular expression parser.
+///
+/// This builder permits modifying configuration options for the parser.
+#[derive(Clone, Debug)]
+pub struct ParserBuilder {
+ ignore_whitespace: bool,
+ nest_limit: u32,
+ octal: bool,
+}
+
+impl Default for ParserBuilder {
+ fn default() -> ParserBuilder {
+ ParserBuilder::new()
+ }
+}
+
+impl ParserBuilder {
+ /// Create a new parser builder with a default configuration.
+ pub fn new() -> ParserBuilder {
+ ParserBuilder {
+ ignore_whitespace: false,
+ nest_limit: 250,
+ octal: false,
+ }
+ }
+
+ /// Build a parser from this configuration with the given pattern.
+ pub fn build(&self) -> Parser {
+ Parser {
+ pos: Cell::new(Position { offset: 0, line: 1, column: 1 }),
+ capture_index: Cell::new(0),
+ nest_limit: self.nest_limit,
+ octal: self.octal,
+ initial_ignore_whitespace: self.ignore_whitespace,
+ ignore_whitespace: Cell::new(self.ignore_whitespace),
+ comments: RefCell::new(vec![]),
+ stack_group: RefCell::new(vec![]),
+ stack_class: RefCell::new(vec![]),
+ capture_names: RefCell::new(vec![]),
+ scratch: RefCell::new(String::new()),
+ }
+ }
+
+ /// Set the nesting limit for this parser.
+ ///
+ /// The nesting limit controls how deep the abstract syntax tree is allowed
+ /// to be. If the AST exceeds the given limit (e.g., with too many nested
+ /// groups), then an error is returned by the parser.
+ ///
+ /// The purpose of this limit is to act as a heuristic to prevent stack
+ /// overflow for consumers that do structural induction on an `Ast` using
+ /// explicit recursion. While this crate never does this (instead using
+ /// constant stack space and moving the call stack to the heap), other
+ /// crates may.
+ ///
+ /// This limit is not checked until the entire Ast is parsed. Therefore,
+ /// if callers want to put a limit on the amount of heap space used, then
+ /// they should impose a limit on the length, in bytes, of the concrete
+ /// pattern string. In particular, this is viable since this parser
+ /// implementation will limit itself to heap space proportional to the
+ /// length of the pattern string.
+ ///
+ /// Note that a nest limit of `0` will return a nest limit error for most
+ /// patterns but not all. For example, a nest limit of `0` permits `a` but
+ /// not `ab`, since `ab` requires a concatenation, which results in a nest
+ /// depth of `1`. In general, a nest limit is not something that manifests
+ /// in an obvious way in the concrete syntax, therefore, it should not be
+ /// used in a granular way.
+ pub fn nest_limit(&mut self, limit: u32) -> &mut ParserBuilder {
+ self.nest_limit = limit;
+ self
+ }
+
+ /// Whether to support octal syntax or not.
+ ///
+ /// Octal syntax is a little-known way of uttering Unicode codepoints in
+ /// a regular expression. For example, `a`, `\x61`, `\u0061` and
+ /// `\141` are all equivalent regular expressions, where the last example
+ /// shows octal syntax.
+ ///
+ /// While supporting octal syntax isn't in and of itself a problem, it does
+ /// make good error messages harder. That is, in PCRE based regex engines,
+ /// syntax like `\0` invokes a backreference, which is explicitly
+ /// unsupported in Rust's regex engine. However, many users expect it to
+ /// be supported. Therefore, when octal support is disabled, the error
+ /// message will explicitly mention that backreferences aren't supported.
+ ///
+ /// Octal syntax is disabled by default.
+ pub fn octal(&mut self, yes: bool) -> &mut ParserBuilder {
+ self.octal = yes;
+ self
+ }
+
+ /// Enable verbose mode in the regular expression.
+ ///
+ /// When enabled, verbose mode permits insignificant whitespace in many
+ /// places in the regular expression, as well as comments. Comments are
+ /// started using `#` and continue until the end of the line.
+ ///
+ /// By default, this is disabled. It may be selectively enabled in the
+ /// regular expression by using the `x` flag regardless of this setting.
+ pub fn ignore_whitespace(&mut self, yes: bool) -> &mut ParserBuilder {
+ self.ignore_whitespace = yes;
+ self
+ }
+}
+
+/// A regular expression parser.
+///
+/// This parses a string representation of a regular expression into an
+/// abstract syntax tree. The size of the tree is proportional to the length
+/// of the regular expression pattern.
+///
+/// A `Parser` can be configured in more detail via a
+/// [`ParserBuilder`](struct.ParserBuilder.html).
+#[derive(Clone, Debug)]
+pub struct Parser {
+ /// The current position of the parser.
+ pos: Cell<Position>,
+ /// The current capture index.
+ capture_index: Cell<u32>,
+ /// The maximum number of open parens/brackets allowed. If the parser
+ /// exceeds this number, then an error is returned.
+ nest_limit: u32,
+ /// Whether to support octal syntax or not. When `false`, the parser will
+ /// return an error helpfully pointing out that backreferences are not
+ /// supported.
+ octal: bool,
+ /// The initial setting for `ignore_whitespace` as provided by
+ /// `ParserBuilder`. It is used when resetting the parser's state.
+ initial_ignore_whitespace: bool,
+ /// Whether whitespace should be ignored. When enabled, comments are
+ /// also permitted.
+ ignore_whitespace: Cell<bool>,
+ /// A list of comments, in order of appearance.
+ comments: RefCell<Vec<ast::Comment>>,
+ /// A stack of grouped sub-expressions, including alternations.
+ stack_group: RefCell<Vec<GroupState>>,
+ /// A stack of nested character classes. This is only non-empty when
+ /// parsing a class.
+ stack_class: RefCell<Vec<ClassState>>,
+ /// A sorted sequence of capture names. This is used to detect duplicate
+ /// capture names and report an error if one is detected.
+ capture_names: RefCell<Vec<ast::CaptureName>>,
+ /// A scratch buffer used in various places. Mostly this is used to
+ /// accumulate relevant characters from parts of a pattern.
+ scratch: RefCell<String>,
+}
+
+/// ParserI is the internal parser implementation.
+///
+/// We use this separate type so that we can carry the provided pattern string
+/// along with us. In particular, a `Parser` internal state is not tied to any
+/// one pattern, but `ParserI` is.
+///
+/// This type also lets us use `ParserI<&Parser>` in production code while
+/// retaining the convenience of `ParserI<Parser>` for tests, which sometimes
+/// work against the internal interface of the parser.
+#[derive(Clone, Debug)]
+struct ParserI<'s, P> {
+ /// The parser state/configuration.
+ parser: P,
+ /// The full regular expression provided by the user.
+ pattern: &'s str,
+}
+
+/// GroupState represents a single stack frame while parsing nested groups
+/// and alternations. Each frame records the state up to an opening parenthesis
+/// or a alternating bracket `|`.
+#[derive(Clone, Debug)]
+enum GroupState {
+ /// This state is pushed whenever an opening group is found.
+ Group {
+ /// The concatenation immediately preceding the opening group.
+ concat: ast::Concat,
+ /// The group that has been opened. Its sub-AST is always empty.
+ group: ast::Group,
+ /// Whether this group has the `x` flag enabled or not.
+ ignore_whitespace: bool,
+ },
+ /// This state is pushed whenever a new alternation branch is found. If
+ /// an alternation branch is found and this state is at the top of the
+ /// stack, then this state should be modified to include the new
+ /// alternation.
+ Alternation(ast::Alternation),
+}
+
+/// ClassState represents a single stack frame while parsing character classes.
+/// Each frame records the state up to an intersection, difference, symmetric
+/// difference or nested class.
+///
+/// Note that a parser's character class stack is only non-empty when parsing
+/// a character class. In all other cases, it is empty.
+#[derive(Clone, Debug)]
+enum ClassState {
+ /// This state is pushed whenever an opening bracket is found.
+ Open {
+ /// The union of class items immediately preceding this class.
+ union: ast::ClassSetUnion,
+ /// The class that has been opened. Typically this just corresponds
+ /// to the `[`, but it can also include `[^` since `^` indicates
+ /// negation of the class.
+ set: ast::ClassBracketed,
+ },
+ /// This state is pushed when a operator is seen. When popped, the stored
+ /// set becomes the left hand side of the operator.
+ Op {
+ /// The type of the operation, i.e., &&, -- or ~~.
+ kind: ast::ClassSetBinaryOpKind,
+ /// The left-hand side of the operator.
+ lhs: ast::ClassSet,
+ },
+}
+
+impl Parser {
+ /// Create a new parser with a default configuration.
+ ///
+ /// The parser can be run with either the `parse` or `parse_with_comments`
+ /// methods. The parse methods return an abstract syntax tree.
+ ///
+ /// To set configuration options on the parser, use
+ /// [`ParserBuilder`](struct.ParserBuilder.html).
+ pub fn new() -> Parser {
+ ParserBuilder::new().build()
+ }
+
+ /// Parse the regular expression into an abstract syntax tree.
+ pub fn parse(&mut self, pattern: &str) -> Result<Ast> {
+ ParserI::new(self, pattern).parse()
+ }
+
+ /// Parse the regular expression and return an abstract syntax tree with
+ /// all of the comments found in the pattern.
+ pub fn parse_with_comments(
+ &mut self,
+ pattern: &str,
+ ) -> Result<ast::WithComments> {
+ ParserI::new(self, pattern).parse_with_comments()
+ }
+
+ /// Reset the internal state of a parser.
+ ///
+ /// This is called at the beginning of every parse. This prevents the
+ /// parser from running with inconsistent state (say, if a previous
+ /// invocation returned an error and the parser is reused).
+ fn reset(&self) {
+ // These settings should be in line with the construction
+ // in `ParserBuilder::build`.
+ self.pos.set(Position { offset: 0, line: 1, column: 1 });
+ self.ignore_whitespace.set(self.initial_ignore_whitespace);
+ self.comments.borrow_mut().clear();
+ self.stack_group.borrow_mut().clear();
+ self.stack_class.borrow_mut().clear();
+ }
+}
+
+impl<'s, P: Borrow<Parser>> ParserI<'s, P> {
+ /// Build an internal parser from a parser configuration and a pattern.
+ fn new(parser: P, pattern: &'s str) -> ParserI<'s, P> {
+ ParserI { parser, pattern }
+ }
+
+ /// Return a reference to the parser state.
+ fn parser(&self) -> &Parser {
+ self.parser.borrow()
+ }
+
+ /// Return a reference to the pattern being parsed.
+ fn pattern(&self) -> &str {
+ self.pattern.borrow()
+ }
+
+ /// Create a new error with the given span and error type.
+ fn error(&self, span: Span, kind: ast::ErrorKind) -> ast::Error {
+ ast::Error { kind, pattern: self.pattern().to_string(), span }
+ }
+
+ /// Return the current offset of the parser.
+ ///
+ /// The offset starts at `0` from the beginning of the regular expression
+ /// pattern string.
+ fn offset(&self) -> usize {
+ self.parser().pos.get().offset
+ }
+
+ /// Return the current line number of the parser.
+ ///
+ /// The line number starts at `1`.
+ fn line(&self) -> usize {
+ self.parser().pos.get().line
+ }
+
+ /// Return the current column of the parser.
+ ///
+ /// The column number starts at `1` and is reset whenever a `\n` is seen.
+ fn column(&self) -> usize {
+ self.parser().pos.get().column
+ }
+
+ /// Return the next capturing index. Each subsequent call increments the
+ /// internal index.
+ ///
+ /// The span given should correspond to the location of the opening
+ /// parenthesis.
+ ///
+ /// If the capture limit is exceeded, then an error is returned.
+ fn next_capture_index(&self, span: Span) -> Result<u32> {
+ let current = self.parser().capture_index.get();
+ let i = current.checked_add(1).ok_or_else(|| {
+ self.error(span, ast::ErrorKind::CaptureLimitExceeded)
+ })?;
+ self.parser().capture_index.set(i);
+ Ok(i)
+ }
+
+ /// Adds the given capture name to this parser. If this capture name has
+ /// already been used, then an error is returned.
+ fn add_capture_name(&self, cap: &ast::CaptureName) -> Result<()> {
+ let mut names = self.parser().capture_names.borrow_mut();
+ match names
+ .binary_search_by_key(&cap.name.as_str(), |c| c.name.as_str())
+ {
+ Err(i) => {
+ names.insert(i, cap.clone());
+ Ok(())
+ }
+ Ok(i) => Err(self.error(
+ cap.span,
+ ast::ErrorKind::GroupNameDuplicate { original: names[i].span },
+ )),
+ }
+ }
+
+ /// Return whether the parser should ignore whitespace or not.
+ fn ignore_whitespace(&self) -> bool {
+ self.parser().ignore_whitespace.get()
+ }
+
+ /// Return the character at the current position of the parser.
+ ///
+ /// This panics if the current position does not point to a valid char.
+ fn char(&self) -> char {
+ self.char_at(self.offset())
+ }
+
+ /// Return the character at the given position.
+ ///
+ /// This panics if the given position does not point to a valid char.
+ fn char_at(&self, i: usize) -> char {
+ self.pattern()[i..]
+ .chars()
+ .next()
+ .unwrap_or_else(|| panic!("expected char at offset {}", i))
+ }
+
+ /// Bump the parser to the next Unicode scalar value.
+ ///
+ /// If the end of the input has been reached, then `false` is returned.
+ fn bump(&self) -> bool {
+ if self.is_eof() {
+ return false;
+ }
+ let Position { mut offset, mut line, mut column } = self.pos();
+ if self.char() == '\n' {
+ line = line.checked_add(1).unwrap();
+ column = 1;
+ } else {
+ column = column.checked_add(1).unwrap();
+ }
+ offset += self.char().len_utf8();
+ self.parser().pos.set(Position { offset, line, column });
+ self.pattern()[self.offset()..].chars().next().is_some()
+ }
+
+ /// If the substring starting at the current position of the parser has
+ /// the given prefix, then bump the parser to the character immediately
+ /// following the prefix and return true. Otherwise, don't bump the parser
+ /// and return false.
+ fn bump_if(&self, prefix: &str) -> bool {
+ if self.pattern()[self.offset()..].starts_with(prefix) {
+ for _ in 0..prefix.chars().count() {
+ self.bump();
+ }
+ true
+ } else {
+ false
+ }
+ }
+
+ /// Returns true if and only if the parser is positioned at a look-around
+ /// prefix. The conditions under which this returns true must always
+ /// correspond to a regular expression that would otherwise be consider
+ /// invalid.
+ ///
+ /// This should only be called immediately after parsing the opening of
+ /// a group or a set of flags.
+ fn is_lookaround_prefix(&self) -> bool {
+ self.bump_if("?=")
+ || self.bump_if("?!")
+ || self.bump_if("?<=")
+ || self.bump_if("?<!")
+ }
+
+ /// Bump the parser, and if the `x` flag is enabled, bump through any
+ /// subsequent spaces. Return true if and only if the parser is not at
+ /// EOF.
+ fn bump_and_bump_space(&self) -> bool {
+ if !self.bump() {
+ return false;
+ }
+ self.bump_space();
+ !self.is_eof()
+ }
+
+ /// If the `x` flag is enabled (i.e., whitespace insensitivity with
+ /// comments), then this will advance the parser through all whitespace
+ /// and comments to the next non-whitespace non-comment byte.
+ ///
+ /// If the `x` flag is disabled, then this is a no-op.
+ ///
+ /// This should be used selectively throughout the parser where
+ /// arbitrary whitespace is permitted when the `x` flag is enabled. For
+ /// example, `{ 5 , 6}` is equivalent to `{5,6}`.
+ fn bump_space(&self) {
+ if !self.ignore_whitespace() {
+ return;
+ }
+ while !self.is_eof() {
+ if self.char().is_whitespace() {
+ self.bump();
+ } else if self.char() == '#' {
+ let start = self.pos();
+ let mut comment_text = String::new();
+ self.bump();
+ while !self.is_eof() {
+ let c = self.char();
+ self.bump();
+ if c == '\n' {
+ break;
+ }
+ comment_text.push(c);
+ }
+ let comment = ast::Comment {
+ span: Span::new(start, self.pos()),
+ comment: comment_text,
+ };
+ self.parser().comments.borrow_mut().push(comment);
+ } else {
+ break;
+ }
+ }
+ }
+
+ /// Peek at the next character in the input without advancing the parser.
+ ///
+ /// If the input has been exhausted, then this returns `None`.
+ fn peek(&self) -> Option<char> {
+ if self.is_eof() {
+ return None;
+ }
+ self.pattern()[self.offset() + self.char().len_utf8()..].chars().next()
+ }
+
+ /// Like peek, but will ignore spaces when the parser is in whitespace
+ /// insensitive mode.
+ fn peek_space(&self) -> Option<char> {
+ if !self.ignore_whitespace() {
+ return self.peek();
+ }
+ if self.is_eof() {
+ return None;
+ }
+ let mut start = self.offset() + self.char().len_utf8();
+ let mut in_comment = false;
+ for (i, c) in self.pattern()[start..].char_indices() {
+ if c.is_whitespace() {
+ continue;
+ } else if !in_comment && c == '#' {
+ in_comment = true;
+ } else if in_comment && c == '\n' {
+ in_comment = false;
+ } else {
+ start += i;
+ break;
+ }
+ }
+ self.pattern()[start..].chars().next()
+ }
+
+ /// Returns true if the next call to `bump` would return false.
+ fn is_eof(&self) -> bool {
+ self.offset() == self.pattern().len()
+ }
+
+ /// Return the current position of the parser, which includes the offset,
+ /// line and column.
+ fn pos(&self) -> Position {
+ self.parser().pos.get()
+ }
+
+ /// Create a span at the current position of the parser. Both the start
+ /// and end of the span are set.
+ fn span(&self) -> Span {
+ Span::splat(self.pos())
+ }
+
+ /// Create a span that covers the current character.
+ fn span_char(&self) -> Span {
+ let mut next = Position {
+ offset: self.offset().checked_add(self.char().len_utf8()).unwrap(),
+ line: self.line(),
+ column: self.column().checked_add(1).unwrap(),
+ };
+ if self.char() == '\n' {
+ next.line += 1;
+ next.column = 1;
+ }
+ Span::new(self.pos(), next)
+ }
+
+ /// Parse and push a single alternation on to the parser's internal stack.
+ /// If the top of the stack already has an alternation, then add to that
+ /// instead of pushing a new one.
+ ///
+ /// The concatenation given corresponds to a single alternation branch.
+ /// The concatenation returned starts the next branch and is empty.
+ ///
+ /// This assumes the parser is currently positioned at `|` and will advance
+ /// the parser to the character following `|`.
+ #[inline(never)]
+ fn push_alternate(&self, mut concat: ast::Concat) -> Result<ast::Concat> {
+ assert_eq!(self.char(), '|');
+ concat.span.end = self.pos();
+ self.push_or_add_alternation(concat);
+ self.bump();
+ Ok(ast::Concat { span: self.span(), asts: vec![] })
+ }
+
+ /// Pushes or adds the given branch of an alternation to the parser's
+ /// internal stack of state.
+ fn push_or_add_alternation(&self, concat: ast::Concat) {
+ use self::GroupState::*;
+
+ let mut stack = self.parser().stack_group.borrow_mut();
+ if let Some(&mut Alternation(ref mut alts)) = stack.last_mut() {
+ alts.asts.push(concat.into_ast());
+ return;
+ }
+ stack.push(Alternation(ast::Alternation {
+ span: Span::new(concat.span.start, self.pos()),
+ asts: vec![concat.into_ast()],
+ }));
+ }
+
+ /// Parse and push a group AST (and its parent concatenation) on to the
+ /// parser's internal stack. Return a fresh concatenation corresponding
+ /// to the group's sub-AST.
+ ///
+ /// If a set of flags was found (with no group), then the concatenation
+ /// is returned with that set of flags added.
+ ///
+ /// This assumes that the parser is currently positioned on the opening
+ /// parenthesis. It advances the parser to the character at the start
+ /// of the sub-expression (or adjoining expression).
+ ///
+ /// If there was a problem parsing the start of the group, then an error
+ /// is returned.
+ #[inline(never)]
+ fn push_group(&self, mut concat: ast::Concat) -> Result<ast::Concat> {
+ assert_eq!(self.char(), '(');
+ match self.parse_group()? {
+ Either::Left(set) => {
+ let ignore = set.flags.flag_state(ast::Flag::IgnoreWhitespace);
+ if let Some(v) = ignore {
+ self.parser().ignore_whitespace.set(v);
+ }
+
+ concat.asts.push(Ast::Flags(set));
+ Ok(concat)
+ }
+ Either::Right(group) => {
+ let old_ignore_whitespace = self.ignore_whitespace();
+ let new_ignore_whitespace = group
+ .flags()
+ .and_then(|f| f.flag_state(ast::Flag::IgnoreWhitespace))
+ .unwrap_or(old_ignore_whitespace);
+ self.parser().stack_group.borrow_mut().push(
+ GroupState::Group {
+ concat,
+ group,
+ ignore_whitespace: old_ignore_whitespace,
+ },
+ );
+ self.parser().ignore_whitespace.set(new_ignore_whitespace);
+ Ok(ast::Concat { span: self.span(), asts: vec![] })
+ }
+ }
+ }
+
+ /// Pop a group AST from the parser's internal stack and set the group's
+ /// AST to the given concatenation. Return the concatenation containing
+ /// the group.
+ ///
+ /// This assumes that the parser is currently positioned on the closing
+ /// parenthesis and advances the parser to the character following the `)`.
+ ///
+ /// If no such group could be popped, then an unopened group error is
+ /// returned.
+ #[inline(never)]
+ fn pop_group(&self, mut group_concat: ast::Concat) -> Result<ast::Concat> {
+ use self::GroupState::*;
+
+ assert_eq!(self.char(), ')');
+ let mut stack = self.parser().stack_group.borrow_mut();
+ let (mut prior_concat, mut group, ignore_whitespace, alt) = match stack
+ .pop()
+ {
+ Some(Group { concat, group, ignore_whitespace }) => {
+ (concat, group, ignore_whitespace, None)
+ }
+ Some(Alternation(alt)) => match stack.pop() {
+ Some(Group { concat, group, ignore_whitespace }) => {
+ (concat, group, ignore_whitespace, Some(alt))
+ }
+ None | Some(Alternation(_)) => {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::GroupUnopened,
+ ));
+ }
+ },
+ None => {
+ return Err(self
+ .error(self.span_char(), ast::ErrorKind::GroupUnopened));
+ }
+ };
+ self.parser().ignore_whitespace.set(ignore_whitespace);
+ group_concat.span.end = self.pos();
+ self.bump();
+ group.span.end = self.pos();
+ match alt {
+ Some(mut alt) => {
+ alt.span.end = group_concat.span.end;
+ alt.asts.push(group_concat.into_ast());
+ group.ast = Box::new(alt.into_ast());
+ }
+ None => {
+ group.ast = Box::new(group_concat.into_ast());
+ }
+ }
+ prior_concat.asts.push(Ast::Group(group));
+ Ok(prior_concat)
+ }
+
+ /// Pop the last state from the parser's internal stack, if it exists, and
+ /// add the given concatenation to it. There either must be no state or a
+ /// single alternation item on the stack. Any other scenario produces an
+ /// error.
+ ///
+ /// This assumes that the parser has advanced to the end.
+ #[inline(never)]
+ fn pop_group_end(&self, mut concat: ast::Concat) -> Result<Ast> {
+ concat.span.end = self.pos();
+ let mut stack = self.parser().stack_group.borrow_mut();
+ let ast = match stack.pop() {
+ None => Ok(concat.into_ast()),
+ Some(GroupState::Alternation(mut alt)) => {
+ alt.span.end = self.pos();
+ alt.asts.push(concat.into_ast());
+ Ok(Ast::Alternation(alt))
+ }
+ Some(GroupState::Group { group, .. }) => {
+ return Err(
+ self.error(group.span, ast::ErrorKind::GroupUnclosed)
+ );
+ }
+ };
+ // If we try to pop again, there should be nothing.
+ match stack.pop() {
+ None => ast,
+ Some(GroupState::Alternation(_)) => {
+ // This unreachable is unfortunate. This case can't happen
+ // because the only way we can be here is if there were two
+ // `GroupState::Alternation`s adjacent in the parser's stack,
+ // which we guarantee to never happen because we never push a
+ // `GroupState::Alternation` if one is already at the top of
+ // the stack.
+ unreachable!()
+ }
+ Some(GroupState::Group { group, .. }) => {
+ Err(self.error(group.span, ast::ErrorKind::GroupUnclosed))
+ }
+ }
+ }
+
+ /// Parse the opening of a character class and push the current class
+ /// parsing context onto the parser's stack. This assumes that the parser
+ /// is positioned at an opening `[`. The given union should correspond to
+ /// the union of set items built up before seeing the `[`.
+ ///
+ /// If there was a problem parsing the opening of the class, then an error
+ /// is returned. Otherwise, a new union of set items for the class is
+ /// returned (which may be populated with either a `]` or a `-`).
+ #[inline(never)]
+ fn push_class_open(
+ &self,
+ parent_union: ast::ClassSetUnion,
+ ) -> Result<ast::ClassSetUnion> {
+ assert_eq!(self.char(), '[');
+
+ let (nested_set, nested_union) = self.parse_set_class_open()?;
+ self.parser()
+ .stack_class
+ .borrow_mut()
+ .push(ClassState::Open { union: parent_union, set: nested_set });
+ Ok(nested_union)
+ }
+
+ /// Parse the end of a character class set and pop the character class
+ /// parser stack. The union given corresponds to the last union built
+ /// before seeing the closing `]`. The union returned corresponds to the
+ /// parent character class set with the nested class added to it.
+ ///
+ /// This assumes that the parser is positioned at a `]` and will advance
+ /// the parser to the byte immediately following the `]`.
+ ///
+ /// If the stack is empty after popping, then this returns the final
+ /// "top-level" character class AST (where a "top-level" character class
+ /// is one that is not nested inside any other character class).
+ ///
+ /// If there is no corresponding opening bracket on the parser's stack,
+ /// then an error is returned.
+ #[inline(never)]
+ fn pop_class(
+ &self,
+ nested_union: ast::ClassSetUnion,
+ ) -> Result<Either<ast::ClassSetUnion, ast::Class>> {
+ assert_eq!(self.char(), ']');
+
+ let item = ast::ClassSet::Item(nested_union.into_item());
+ let prevset = self.pop_class_op(item);
+ let mut stack = self.parser().stack_class.borrow_mut();
+ match stack.pop() {
+ None => {
+ // We can never observe an empty stack:
+ //
+ // 1) We are guaranteed to start with a non-empty stack since
+ // the character class parser is only initiated when it sees
+ // a `[`.
+ // 2) If we ever observe an empty stack while popping after
+ // seeing a `]`, then we signal the character class parser
+ // to terminate.
+ panic!("unexpected empty character class stack")
+ }
+ Some(ClassState::Op { .. }) => {
+ // This panic is unfortunate, but this case is impossible
+ // since we already popped the Op state if one exists above.
+ // Namely, every push to the class parser stack is guarded by
+ // whether an existing Op is already on the top of the stack.
+ // If it is, the existing Op is modified. That is, the stack
+ // can never have consecutive Op states.
+ panic!("unexpected ClassState::Op")
+ }
+ Some(ClassState::Open { mut union, mut set }) => {
+ self.bump();
+ set.span.end = self.pos();
+ set.kind = prevset;
+ if stack.is_empty() {
+ Ok(Either::Right(ast::Class::Bracketed(set)))
+ } else {
+ union.push(ast::ClassSetItem::Bracketed(Box::new(set)));
+ Ok(Either::Left(union))
+ }
+ }
+ }
+ }
+
+ /// Return an "unclosed class" error whose span points to the most
+ /// recently opened class.
+ ///
+ /// This should only be called while parsing a character class.
+ #[inline(never)]
+ fn unclosed_class_error(&self) -> ast::Error {
+ for state in self.parser().stack_class.borrow().iter().rev() {
+ if let ClassState::Open { ref set, .. } = *state {
+ return self.error(set.span, ast::ErrorKind::ClassUnclosed);
+ }
+ }
+ // We are guaranteed to have a non-empty stack with at least
+ // one open bracket, so we should never get here.
+ panic!("no open character class found")
+ }
+
+ /// Push the current set of class items on to the class parser's stack as
+ /// the left hand side of the given operator.
+ ///
+ /// A fresh set union is returned, which should be used to build the right
+ /// hand side of this operator.
+ #[inline(never)]
+ fn push_class_op(
+ &self,
+ next_kind: ast::ClassSetBinaryOpKind,
+ next_union: ast::ClassSetUnion,
+ ) -> ast::ClassSetUnion {
+ let item = ast::ClassSet::Item(next_union.into_item());
+ let new_lhs = self.pop_class_op(item);
+ self.parser()
+ .stack_class
+ .borrow_mut()
+ .push(ClassState::Op { kind: next_kind, lhs: new_lhs });
+ ast::ClassSetUnion { span: self.span(), items: vec![] }
+ }
+
+ /// Pop a character class set from the character class parser stack. If the
+ /// top of the stack is just an item (not an operation), then return the
+ /// given set unchanged. If the top of the stack is an operation, then the
+ /// given set will be used as the rhs of the operation on the top of the
+ /// stack. In that case, the binary operation is returned as a set.
+ #[inline(never)]
+ fn pop_class_op(&self, rhs: ast::ClassSet) -> ast::ClassSet {
+ let mut stack = self.parser().stack_class.borrow_mut();
+ let (kind, lhs) = match stack.pop() {
+ Some(ClassState::Op { kind, lhs }) => (kind, lhs),
+ Some(state @ ClassState::Open { .. }) => {
+ stack.push(state);
+ return rhs;
+ }
+ None => unreachable!(),
+ };
+ let span = Span::new(lhs.span().start, rhs.span().end);
+ ast::ClassSet::BinaryOp(ast::ClassSetBinaryOp {
+ span,
+ kind,
+ lhs: Box::new(lhs),
+ rhs: Box::new(rhs),
+ })
+ }
+}
+
+impl<'s, P: Borrow<Parser>> ParserI<'s, P> {
+ /// Parse the regular expression into an abstract syntax tree.
+ fn parse(&self) -> Result<Ast> {
+ self.parse_with_comments().map(|astc| astc.ast)
+ }
+
+ /// Parse the regular expression and return an abstract syntax tree with
+ /// all of the comments found in the pattern.
+ fn parse_with_comments(&self) -> Result<ast::WithComments> {
+ assert_eq!(self.offset(), 0, "parser can only be used once");
+ self.parser().reset();
+ let mut concat = ast::Concat { span: self.span(), asts: vec![] };
+ loop {
+ self.bump_space();
+ if self.is_eof() {
+ break;
+ }
+ match self.char() {
+ '(' => concat = self.push_group(concat)?,
+ ')' => concat = self.pop_group(concat)?,
+ '|' => concat = self.push_alternate(concat)?,
+ '[' => {
+ let class = self.parse_set_class()?;
+ concat.asts.push(Ast::Class(class));
+ }
+ '?' => {
+ concat = self.parse_uncounted_repetition(
+ concat,
+ ast::RepetitionKind::ZeroOrOne,
+ )?;
+ }
+ '*' => {
+ concat = self.parse_uncounted_repetition(
+ concat,
+ ast::RepetitionKind::ZeroOrMore,
+ )?;
+ }
+ '+' => {
+ concat = self.parse_uncounted_repetition(
+ concat,
+ ast::RepetitionKind::OneOrMore,
+ )?;
+ }
+ '{' => {
+ concat = self.parse_counted_repetition(concat)?;
+ }
+ _ => concat.asts.push(self.parse_primitive()?.into_ast()),
+ }
+ }
+ let ast = self.pop_group_end(concat)?;
+ NestLimiter::new(self).check(&ast)?;
+ Ok(ast::WithComments {
+ ast,
+ comments: mem::replace(
+ &mut *self.parser().comments.borrow_mut(),
+ vec![],
+ ),
+ })
+ }
+
+ /// Parses an uncounted repetition operation. An uncounted repetition
+ /// operator includes ?, * and +, but does not include the {m,n} syntax.
+ /// The given `kind` should correspond to the operator observed by the
+ /// caller.
+ ///
+ /// This assumes that the parser is currently positioned at the repetition
+ /// operator and advances the parser to the first character after the
+ /// operator. (Note that the operator may include a single additional `?`,
+ /// which makes the operator ungreedy.)
+ ///
+ /// The caller should include the concatenation that is being built. The
+ /// concatenation returned includes the repetition operator applied to the
+ /// last expression in the given concatenation.
+ #[inline(never)]
+ fn parse_uncounted_repetition(
+ &self,
+ mut concat: ast::Concat,
+ kind: ast::RepetitionKind,
+ ) -> Result<ast::Concat> {
+ assert!(
+ self.char() == '?' || self.char() == '*' || self.char() == '+'
+ );
+ let op_start = self.pos();
+ let ast = match concat.asts.pop() {
+ Some(ast) => ast,
+ None => {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::RepetitionMissing)
+ )
+ }
+ };
+ match ast {
+ Ast::Empty(_) | Ast::Flags(_) => {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::RepetitionMissing)
+ )
+ }
+ _ => {}
+ }
+ let mut greedy = true;
+ if self.bump() && self.char() == '?' {
+ greedy = false;
+ self.bump();
+ }
+ concat.asts.push(Ast::Repetition(ast::Repetition {
+ span: ast.span().with_end(self.pos()),
+ op: ast::RepetitionOp {
+ span: Span::new(op_start, self.pos()),
+ kind,
+ },
+ greedy,
+ ast: Box::new(ast),
+ }));
+ Ok(concat)
+ }
+
+ /// Parses a counted repetition operation. A counted repetition operator
+ /// corresponds to the {m,n} syntax, and does not include the ?, * or +
+ /// operators.
+ ///
+ /// This assumes that the parser is currently positioned at the opening `{`
+ /// and advances the parser to the first character after the operator.
+ /// (Note that the operator may include a single additional `?`, which
+ /// makes the operator ungreedy.)
+ ///
+ /// The caller should include the concatenation that is being built. The
+ /// concatenation returned includes the repetition operator applied to the
+ /// last expression in the given concatenation.
+ #[inline(never)]
+ fn parse_counted_repetition(
+ &self,
+ mut concat: ast::Concat,
+ ) -> Result<ast::Concat> {
+ assert!(self.char() == '{');
+ let start = self.pos();
+ let ast = match concat.asts.pop() {
+ Some(ast) => ast,
+ None => {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::RepetitionMissing)
+ )
+ }
+ };
+ match ast {
+ Ast::Empty(_) | Ast::Flags(_) => {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::RepetitionMissing)
+ )
+ }
+ _ => {}
+ }
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::RepetitionCountUnclosed,
+ ));
+ }
+ let count_start = specialize_err(
+ self.parse_decimal(),
+ ast::ErrorKind::DecimalEmpty,
+ ast::ErrorKind::RepetitionCountDecimalEmpty,
+ )?;
+ let mut range = ast::RepetitionRange::Exactly(count_start);
+ if self.is_eof() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::RepetitionCountUnclosed,
+ ));
+ }
+ if self.char() == ',' {
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::RepetitionCountUnclosed,
+ ));
+ }
+ if self.char() != '}' {
+ let count_end = specialize_err(
+ self.parse_decimal(),
+ ast::ErrorKind::DecimalEmpty,
+ ast::ErrorKind::RepetitionCountDecimalEmpty,
+ )?;
+ range = ast::RepetitionRange::Bounded(count_start, count_end);
+ } else {
+ range = ast::RepetitionRange::AtLeast(count_start);
+ }
+ }
+ if self.is_eof() || self.char() != '}' {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::RepetitionCountUnclosed,
+ ));
+ }
+
+ let mut greedy = true;
+ if self.bump_and_bump_space() && self.char() == '?' {
+ greedy = false;
+ self.bump();
+ }
+
+ let op_span = Span::new(start, self.pos());
+ if !range.is_valid() {
+ return Err(
+ self.error(op_span, ast::ErrorKind::RepetitionCountInvalid)
+ );
+ }
+ concat.asts.push(Ast::Repetition(ast::Repetition {
+ span: ast.span().with_end(self.pos()),
+ op: ast::RepetitionOp {
+ span: op_span,
+ kind: ast::RepetitionKind::Range(range),
+ },
+ greedy,
+ ast: Box::new(ast),
+ }));
+ Ok(concat)
+ }
+
+ /// Parse a group (which contains a sub-expression) or a set of flags.
+ ///
+ /// If a group was found, then it is returned with an empty AST. If a set
+ /// of flags is found, then that set is returned.
+ ///
+ /// The parser should be positioned at the opening parenthesis.
+ ///
+ /// This advances the parser to the character before the start of the
+ /// sub-expression (in the case of a group) or to the closing parenthesis
+ /// immediately following the set of flags.
+ ///
+ /// # Errors
+ ///
+ /// If flags are given and incorrectly specified, then a corresponding
+ /// error is returned.
+ ///
+ /// If a capture name is given and it is incorrectly specified, then a
+ /// corresponding error is returned.
+ #[inline(never)]
+ fn parse_group(&self) -> Result<Either<ast::SetFlags, ast::Group>> {
+ assert_eq!(self.char(), '(');
+ let open_span = self.span_char();
+ self.bump();
+ self.bump_space();
+ if self.is_lookaround_prefix() {
+ return Err(self.error(
+ Span::new(open_span.start, self.span().end),
+ ast::ErrorKind::UnsupportedLookAround,
+ ));
+ }
+ let inner_span = self.span();
+ if self.bump_if("?P<") {
+ let capture_index = self.next_capture_index(open_span)?;
+ let cap = self.parse_capture_name(capture_index)?;
+ Ok(Either::Right(ast::Group {
+ span: open_span,
+ kind: ast::GroupKind::CaptureName(cap),
+ ast: Box::new(Ast::Empty(self.span())),
+ }))
+ } else if self.bump_if("?") {
+ if self.is_eof() {
+ return Err(
+ self.error(open_span, ast::ErrorKind::GroupUnclosed)
+ );
+ }
+ let flags = self.parse_flags()?;
+ let char_end = self.char();
+ self.bump();
+ if char_end == ')' {
+ // We don't allow empty flags, e.g., `(?)`. We instead
+ // interpret it as a repetition operator missing its argument.
+ if flags.items.is_empty() {
+ return Err(self.error(
+ inner_span,
+ ast::ErrorKind::RepetitionMissing,
+ ));
+ }
+ Ok(Either::Left(ast::SetFlags {
+ span: Span { end: self.pos(), ..open_span },
+ flags,
+ }))
+ } else {
+ assert_eq!(char_end, ':');
+ Ok(Either::Right(ast::Group {
+ span: open_span,
+ kind: ast::GroupKind::NonCapturing(flags),
+ ast: Box::new(Ast::Empty(self.span())),
+ }))
+ }
+ } else {
+ let capture_index = self.next_capture_index(open_span)?;
+ Ok(Either::Right(ast::Group {
+ span: open_span,
+ kind: ast::GroupKind::CaptureIndex(capture_index),
+ ast: Box::new(Ast::Empty(self.span())),
+ }))
+ }
+ }
+
+ /// Parses a capture group name. Assumes that the parser is positioned at
+ /// the first character in the name following the opening `<` (and may
+ /// possibly be EOF). This advances the parser to the first character
+ /// following the closing `>`.
+ ///
+ /// The caller must provide the capture index of the group for this name.
+ #[inline(never)]
+ fn parse_capture_name(
+ &self,
+ capture_index: u32,
+ ) -> Result<ast::CaptureName> {
+ if self.is_eof() {
+ return Err(self
+ .error(self.span(), ast::ErrorKind::GroupNameUnexpectedEof));
+ }
+ let start = self.pos();
+ loop {
+ if self.char() == '>' {
+ break;
+ }
+ if !is_capture_char(self.char(), self.pos() == start) {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::GroupNameInvalid,
+ ));
+ }
+ if !self.bump() {
+ break;
+ }
+ }
+ let end = self.pos();
+ if self.is_eof() {
+ return Err(self
+ .error(self.span(), ast::ErrorKind::GroupNameUnexpectedEof));
+ }
+ assert_eq!(self.char(), '>');
+ self.bump();
+ let name = &self.pattern()[start.offset..end.offset];
+ if name.is_empty() {
+ return Err(self.error(
+ Span::new(start, start),
+ ast::ErrorKind::GroupNameEmpty,
+ ));
+ }
+ let capname = ast::CaptureName {
+ span: Span::new(start, end),
+ name: name.to_string(),
+ index: capture_index,
+ };
+ self.add_capture_name(&capname)?;
+ Ok(capname)
+ }
+
+ /// Parse a sequence of flags starting at the current character.
+ ///
+ /// This advances the parser to the character immediately following the
+ /// flags, which is guaranteed to be either `:` or `)`.
+ ///
+ /// # Errors
+ ///
+ /// If any flags are duplicated, then an error is returned.
+ ///
+ /// If the negation operator is used more than once, then an error is
+ /// returned.
+ ///
+ /// If no flags could be found or if the negation operation is not followed
+ /// by any flags, then an error is returned.
+ #[inline(never)]
+ fn parse_flags(&self) -> Result<ast::Flags> {
+ let mut flags = ast::Flags { span: self.span(), items: vec![] };
+ let mut last_was_negation = None;
+ while self.char() != ':' && self.char() != ')' {
+ if self.char() == '-' {
+ last_was_negation = Some(self.span_char());
+ let item = ast::FlagsItem {
+ span: self.span_char(),
+ kind: ast::FlagsItemKind::Negation,
+ };
+ if let Some(i) = flags.add_item(item) {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::FlagRepeatedNegation {
+ original: flags.items[i].span,
+ },
+ ));
+ }
+ } else {
+ last_was_negation = None;
+ let item = ast::FlagsItem {
+ span: self.span_char(),
+ kind: ast::FlagsItemKind::Flag(self.parse_flag()?),
+ };
+ if let Some(i) = flags.add_item(item) {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::FlagDuplicate {
+ original: flags.items[i].span,
+ },
+ ));
+ }
+ }
+ if !self.bump() {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::FlagUnexpectedEof)
+ );
+ }
+ }
+ if let Some(span) = last_was_negation {
+ return Err(self.error(span, ast::ErrorKind::FlagDanglingNegation));
+ }
+ flags.span.end = self.pos();
+ Ok(flags)
+ }
+
+ /// Parse the current character as a flag. Do not advance the parser.
+ ///
+ /// # Errors
+ ///
+ /// If the flag is not recognized, then an error is returned.
+ #[inline(never)]
+ fn parse_flag(&self) -> Result<ast::Flag> {
+ match self.char() {
+ 'i' => Ok(ast::Flag::CaseInsensitive),
+ 'm' => Ok(ast::Flag::MultiLine),
+ 's' => Ok(ast::Flag::DotMatchesNewLine),
+ 'U' => Ok(ast::Flag::SwapGreed),
+ 'u' => Ok(ast::Flag::Unicode),
+ 'x' => Ok(ast::Flag::IgnoreWhitespace),
+ _ => {
+ Err(self
+ .error(self.span_char(), ast::ErrorKind::FlagUnrecognized))
+ }
+ }
+ }
+
+ /// Parse a primitive AST. e.g., A literal, non-set character class or
+ /// assertion.
+ ///
+ /// This assumes that the parser expects a primitive at the current
+ /// location. i.e., All other non-primitive cases have been handled.
+ /// For example, if the parser's position is at `|`, then `|` will be
+ /// treated as a literal (e.g., inside a character class).
+ ///
+ /// This advances the parser to the first character immediately following
+ /// the primitive.
+ fn parse_primitive(&self) -> Result<Primitive> {
+ match self.char() {
+ '\\' => self.parse_escape(),
+ '.' => {
+ let ast = Primitive::Dot(self.span_char());
+ self.bump();
+ Ok(ast)
+ }
+ '^' => {
+ let ast = Primitive::Assertion(ast::Assertion {
+ span: self.span_char(),
+ kind: ast::AssertionKind::StartLine,
+ });
+ self.bump();
+ Ok(ast)
+ }
+ '$' => {
+ let ast = Primitive::Assertion(ast::Assertion {
+ span: self.span_char(),
+ kind: ast::AssertionKind::EndLine,
+ });
+ self.bump();
+ Ok(ast)
+ }
+ c => {
+ let ast = Primitive::Literal(ast::Literal {
+ span: self.span_char(),
+ kind: ast::LiteralKind::Verbatim,
+ c,
+ });
+ self.bump();
+ Ok(ast)
+ }
+ }
+ }
+
+ /// Parse an escape sequence as a primitive AST.
+ ///
+ /// This assumes the parser is positioned at the start of the escape
+ /// sequence, i.e., `\`. It advances the parser to the first position
+ /// immediately following the escape sequence.
+ #[inline(never)]
+ fn parse_escape(&self) -> Result<Primitive> {
+ assert_eq!(self.char(), '\\');
+ let start = self.pos();
+ if !self.bump() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::EscapeUnexpectedEof,
+ ));
+ }
+ let c = self.char();
+ // Put some of the more complicated routines into helpers.
+ match c {
+ '0'..='7' => {
+ if !self.parser().octal {
+ return Err(self.error(
+ Span::new(start, self.span_char().end),
+ ast::ErrorKind::UnsupportedBackreference,
+ ));
+ }
+ let mut lit = self.parse_octal();
+ lit.span.start = start;
+ return Ok(Primitive::Literal(lit));
+ }
+ '8'..='9' if !self.parser().octal => {
+ return Err(self.error(
+ Span::new(start, self.span_char().end),
+ ast::ErrorKind::UnsupportedBackreference,
+ ));
+ }
+ 'x' | 'u' | 'U' => {
+ let mut lit = self.parse_hex()?;
+ lit.span.start = start;
+ return Ok(Primitive::Literal(lit));
+ }
+ 'p' | 'P' => {
+ let mut cls = self.parse_unicode_class()?;
+ cls.span.start = start;
+ return Ok(Primitive::Unicode(cls));
+ }
+ 'd' | 's' | 'w' | 'D' | 'S' | 'W' => {
+ let mut cls = self.parse_perl_class();
+ cls.span.start = start;
+ return Ok(Primitive::Perl(cls));
+ }
+ _ => {}
+ }
+
+ // Handle all of the one letter sequences inline.
+ self.bump();
+ let span = Span::new(start, self.pos());
+ if is_meta_character(c) {
+ return Ok(Primitive::Literal(ast::Literal {
+ span,
+ kind: ast::LiteralKind::Punctuation,
+ c,
+ }));
+ }
+ let special = |kind, c| {
+ Ok(Primitive::Literal(ast::Literal {
+ span,
+ kind: ast::LiteralKind::Special(kind),
+ c,
+ }))
+ };
+ match c {
+ 'a' => special(ast::SpecialLiteralKind::Bell, '\x07'),
+ 'f' => special(ast::SpecialLiteralKind::FormFeed, '\x0C'),
+ 't' => special(ast::SpecialLiteralKind::Tab, '\t'),
+ 'n' => special(ast::SpecialLiteralKind::LineFeed, '\n'),
+ 'r' => special(ast::SpecialLiteralKind::CarriageReturn, '\r'),
+ 'v' => special(ast::SpecialLiteralKind::VerticalTab, '\x0B'),
+ ' ' if self.ignore_whitespace() => {
+ special(ast::SpecialLiteralKind::Space, ' ')
+ }
+ 'A' => Ok(Primitive::Assertion(ast::Assertion {
+ span,
+ kind: ast::AssertionKind::StartText,
+ })),
+ 'z' => Ok(Primitive::Assertion(ast::Assertion {
+ span,
+ kind: ast::AssertionKind::EndText,
+ })),
+ 'b' => Ok(Primitive::Assertion(ast::Assertion {
+ span,
+ kind: ast::AssertionKind::WordBoundary,
+ })),
+ 'B' => Ok(Primitive::Assertion(ast::Assertion {
+ span,
+ kind: ast::AssertionKind::NotWordBoundary,
+ })),
+ _ => Err(self.error(span, ast::ErrorKind::EscapeUnrecognized)),
+ }
+ }
+
+ /// Parse an octal representation of a Unicode codepoint up to 3 digits
+ /// long. This expects the parser to be positioned at the first octal
+ /// digit and advances the parser to the first character immediately
+ /// following the octal number. This also assumes that parsing octal
+ /// escapes is enabled.
+ ///
+ /// Assuming the preconditions are met, this routine can never fail.
+ #[inline(never)]
+ fn parse_octal(&self) -> ast::Literal {
+ use std::char;
+ use std::u32;
+
+ assert!(self.parser().octal);
+ assert!('0' <= self.char() && self.char() <= '7');
+ let start = self.pos();
+ // Parse up to two more digits.
+ while self.bump()
+ && '0' <= self.char()
+ && self.char() <= '7'
+ && self.pos().offset - start.offset <= 2
+ {}
+ let end = self.pos();
+ let octal = &self.pattern()[start.offset..end.offset];
+ // Parsing the octal should never fail since the above guarantees a
+ // valid number.
+ let codepoint =
+ u32::from_str_radix(octal, 8).expect("valid octal number");
+ // The max value for 3 digit octal is 0777 = 511 and [0, 511] has no
+ // invalid Unicode scalar values.
+ let c = char::from_u32(codepoint).expect("Unicode scalar value");
+ ast::Literal {
+ span: Span::new(start, end),
+ kind: ast::LiteralKind::Octal,
+ c,
+ }
+ }
+
+ /// Parse a hex representation of a Unicode codepoint. This handles both
+ /// hex notations, i.e., `\xFF` and `\x{FFFF}`. This expects the parser to
+ /// be positioned at the `x`, `u` or `U` prefix. The parser is advanced to
+ /// the first character immediately following the hexadecimal literal.
+ #[inline(never)]
+ fn parse_hex(&self) -> Result<ast::Literal> {
+ assert!(
+ self.char() == 'x' || self.char() == 'u' || self.char() == 'U'
+ );
+
+ let hex_kind = match self.char() {
+ 'x' => ast::HexLiteralKind::X,
+ 'u' => ast::HexLiteralKind::UnicodeShort,
+ _ => ast::HexLiteralKind::UnicodeLong,
+ };
+ if !self.bump_and_bump_space() {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::EscapeUnexpectedEof)
+ );
+ }
+ if self.char() == '{' {
+ self.parse_hex_brace(hex_kind)
+ } else {
+ self.parse_hex_digits(hex_kind)
+ }
+ }
+
+ /// Parse an N-digit hex representation of a Unicode codepoint. This
+ /// expects the parser to be positioned at the first digit and will advance
+ /// the parser to the first character immediately following the escape
+ /// sequence.
+ ///
+ /// The number of digits given must be 2 (for `\xNN`), 4 (for `\uNNNN`)
+ /// or 8 (for `\UNNNNNNNN`).
+ #[inline(never)]
+ fn parse_hex_digits(
+ &self,
+ kind: ast::HexLiteralKind,
+ ) -> Result<ast::Literal> {
+ use std::char;
+ use std::u32;
+
+ let mut scratch = self.parser().scratch.borrow_mut();
+ scratch.clear();
+
+ let start = self.pos();
+ for i in 0..kind.digits() {
+ if i > 0 && !self.bump_and_bump_space() {
+ return Err(self
+ .error(self.span(), ast::ErrorKind::EscapeUnexpectedEof));
+ }
+ if !is_hex(self.char()) {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::EscapeHexInvalidDigit,
+ ));
+ }
+ scratch.push(self.char());
+ }
+ // The final bump just moves the parser past the literal, which may
+ // be EOF.
+ self.bump_and_bump_space();
+ let end = self.pos();
+ let hex = scratch.as_str();
+ match u32::from_str_radix(hex, 16).ok().and_then(char::from_u32) {
+ None => Err(self.error(
+ Span::new(start, end),
+ ast::ErrorKind::EscapeHexInvalid,
+ )),
+ Some(c) => Ok(ast::Literal {
+ span: Span::new(start, end),
+ kind: ast::LiteralKind::HexFixed(kind),
+ c,
+ }),
+ }
+ }
+
+ /// Parse a hex representation of any Unicode scalar value. This expects
+ /// the parser to be positioned at the opening brace `{` and will advance
+ /// the parser to the first character following the closing brace `}`.
+ #[inline(never)]
+ fn parse_hex_brace(
+ &self,
+ kind: ast::HexLiteralKind,
+ ) -> Result<ast::Literal> {
+ use std::char;
+ use std::u32;
+
+ let mut scratch = self.parser().scratch.borrow_mut();
+ scratch.clear();
+
+ let brace_pos = self.pos();
+ let start = self.span_char().end;
+ while self.bump_and_bump_space() && self.char() != '}' {
+ if !is_hex(self.char()) {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::EscapeHexInvalidDigit,
+ ));
+ }
+ scratch.push(self.char());
+ }
+ if self.is_eof() {
+ return Err(self.error(
+ Span::new(brace_pos, self.pos()),
+ ast::ErrorKind::EscapeUnexpectedEof,
+ ));
+ }
+ let end = self.pos();
+ let hex = scratch.as_str();
+ assert_eq!(self.char(), '}');
+ self.bump_and_bump_space();
+
+ if hex.is_empty() {
+ return Err(self.error(
+ Span::new(brace_pos, self.pos()),
+ ast::ErrorKind::EscapeHexEmpty,
+ ));
+ }
+ match u32::from_str_radix(hex, 16).ok().and_then(char::from_u32) {
+ None => Err(self.error(
+ Span::new(start, end),
+ ast::ErrorKind::EscapeHexInvalid,
+ )),
+ Some(c) => Ok(ast::Literal {
+ span: Span::new(start, self.pos()),
+ kind: ast::LiteralKind::HexBrace(kind),
+ c,
+ }),
+ }
+ }
+
+ /// Parse a decimal number into a u32 while trimming leading and trailing
+ /// whitespace.
+ ///
+ /// This expects the parser to be positioned at the first position where
+ /// a decimal digit could occur. This will advance the parser to the byte
+ /// immediately following the last contiguous decimal digit.
+ ///
+ /// If no decimal digit could be found or if there was a problem parsing
+ /// the complete set of digits into a u32, then an error is returned.
+ fn parse_decimal(&self) -> Result<u32> {
+ let mut scratch = self.parser().scratch.borrow_mut();
+ scratch.clear();
+
+ while !self.is_eof() && self.char().is_whitespace() {
+ self.bump();
+ }
+ let start = self.pos();
+ while !self.is_eof() && '0' <= self.char() && self.char() <= '9' {
+ scratch.push(self.char());
+ self.bump_and_bump_space();
+ }
+ let span = Span::new(start, self.pos());
+ while !self.is_eof() && self.char().is_whitespace() {
+ self.bump_and_bump_space();
+ }
+ let digits = scratch.as_str();
+ if digits.is_empty() {
+ return Err(self.error(span, ast::ErrorKind::DecimalEmpty));
+ }
+ match u32::from_str_radix(digits, 10).ok() {
+ Some(n) => Ok(n),
+ None => Err(self.error(span, ast::ErrorKind::DecimalInvalid)),
+ }
+ }
+
+ /// Parse a standard character class consisting primarily of characters or
+ /// character ranges, but can also contain nested character classes of
+ /// any type (sans `.`).
+ ///
+ /// This assumes the parser is positioned at the opening `[`. If parsing
+ /// is successful, then the parser is advanced to the position immediately
+ /// following the closing `]`.
+ #[inline(never)]
+ fn parse_set_class(&self) -> Result<ast::Class> {
+ assert_eq!(self.char(), '[');
+
+ let mut union =
+ ast::ClassSetUnion { span: self.span(), items: vec![] };
+ loop {
+ self.bump_space();
+ if self.is_eof() {
+ return Err(self.unclosed_class_error());
+ }
+ match self.char() {
+ '[' => {
+ // If we've already parsed the opening bracket, then
+ // attempt to treat this as the beginning of an ASCII
+ // class. If ASCII class parsing fails, then the parser
+ // backs up to `[`.
+ if !self.parser().stack_class.borrow().is_empty() {
+ if let Some(cls) = self.maybe_parse_ascii_class() {
+ union.push(ast::ClassSetItem::Ascii(cls));
+ continue;
+ }
+ }
+ union = self.push_class_open(union)?;
+ }
+ ']' => match self.pop_class(union)? {
+ Either::Left(nested_union) => {
+ union = nested_union;
+ }
+ Either::Right(class) => return Ok(class),
+ },
+ '&' if self.peek() == Some('&') => {
+ assert!(self.bump_if("&&"));
+ union = self.push_class_op(
+ ast::ClassSetBinaryOpKind::Intersection,
+ union,
+ );
+ }
+ '-' if self.peek() == Some('-') => {
+ assert!(self.bump_if("--"));
+ union = self.push_class_op(
+ ast::ClassSetBinaryOpKind::Difference,
+ union,
+ );
+ }
+ '~' if self.peek() == Some('~') => {
+ assert!(self.bump_if("~~"));
+ union = self.push_class_op(
+ ast::ClassSetBinaryOpKind::SymmetricDifference,
+ union,
+ );
+ }
+ _ => {
+ union.push(self.parse_set_class_range()?);
+ }
+ }
+ }
+ }
+
+ /// Parse a single primitive item in a character class set. The item to
+ /// be parsed can either be one of a simple literal character, a range
+ /// between two simple literal characters or a "primitive" character
+ /// class like \w or \p{Greek}.
+ ///
+ /// If an invalid escape is found, or if a character class is found where
+ /// a simple literal is expected (e.g., in a range), then an error is
+ /// returned.
+ #[inline(never)]
+ fn parse_set_class_range(&self) -> Result<ast::ClassSetItem> {
+ let prim1 = self.parse_set_class_item()?;
+ self.bump_space();
+ if self.is_eof() {
+ return Err(self.unclosed_class_error());
+ }
+ // If the next char isn't a `-`, then we don't have a range.
+ // There are two exceptions. If the char after a `-` is a `]`, then
+ // `-` is interpreted as a literal `-`. Alternatively, if the char
+ // after a `-` is a `-`, then `--` corresponds to a "difference"
+ // operation.
+ if self.char() != '-'
+ || self.peek_space() == Some(']')
+ || self.peek_space() == Some('-')
+ {
+ return prim1.into_class_set_item(self);
+ }
+ // OK, now we're parsing a range, so bump past the `-` and parse the
+ // second half of the range.
+ if !self.bump_and_bump_space() {
+ return Err(self.unclosed_class_error());
+ }
+ let prim2 = self.parse_set_class_item()?;
+ let range = ast::ClassSetRange {
+ span: Span::new(prim1.span().start, prim2.span().end),
+ start: prim1.into_class_literal(self)?,
+ end: prim2.into_class_literal(self)?,
+ };
+ if !range.is_valid() {
+ return Err(
+ self.error(range.span, ast::ErrorKind::ClassRangeInvalid)
+ );
+ }
+ Ok(ast::ClassSetItem::Range(range))
+ }
+
+ /// Parse a single item in a character class as a primitive, where the
+ /// primitive either consists of a verbatim literal or a single escape
+ /// sequence.
+ ///
+ /// This assumes the parser is positioned at the beginning of a primitive,
+ /// and advances the parser to the first position after the primitive if
+ /// successful.
+ ///
+ /// Note that it is the caller's responsibility to report an error if an
+ /// illegal primitive was parsed.
+ #[inline(never)]
+ fn parse_set_class_item(&self) -> Result<Primitive> {
+ if self.char() == '\\' {
+ self.parse_escape()
+ } else {
+ let x = Primitive::Literal(ast::Literal {
+ span: self.span_char(),
+ kind: ast::LiteralKind::Verbatim,
+ c: self.char(),
+ });
+ self.bump();
+ Ok(x)
+ }
+ }
+
+ /// Parses the opening of a character class set. This includes the opening
+ /// bracket along with `^` if present to indicate negation. This also
+ /// starts parsing the opening set of unioned items if applicable, since
+ /// there are special rules applied to certain characters in the opening
+ /// of a character class. For example, `[^]]` is the class of all
+ /// characters not equal to `]`. (`]` would need to be escaped in any other
+ /// position.) Similarly for `-`.
+ ///
+ /// In all cases, the op inside the returned `ast::ClassBracketed` is an
+ /// empty union. This empty union should be replaced with the actual item
+ /// when it is popped from the parser's stack.
+ ///
+ /// This assumes the parser is positioned at the opening `[` and advances
+ /// the parser to the first non-special byte of the character class.
+ ///
+ /// An error is returned if EOF is found.
+ #[inline(never)]
+ fn parse_set_class_open(
+ &self,
+ ) -> Result<(ast::ClassBracketed, ast::ClassSetUnion)> {
+ assert_eq!(self.char(), '[');
+ let start = self.pos();
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::ClassUnclosed,
+ ));
+ }
+
+ let negated = if self.char() != '^' {
+ false
+ } else {
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::ClassUnclosed,
+ ));
+ }
+ true
+ };
+ // Accept any number of `-` as literal `-`.
+ let mut union =
+ ast::ClassSetUnion { span: self.span(), items: vec![] };
+ while self.char() == '-' {
+ union.push(ast::ClassSetItem::Literal(ast::Literal {
+ span: self.span_char(),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ }));
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, start),
+ ast::ErrorKind::ClassUnclosed,
+ ));
+ }
+ }
+ // If `]` is the *first* char in a set, then interpret it as a literal
+ // `]`. That is, an empty class is impossible to write.
+ if union.items.is_empty() && self.char() == ']' {
+ union.push(ast::ClassSetItem::Literal(ast::Literal {
+ span: self.span_char(),
+ kind: ast::LiteralKind::Verbatim,
+ c: ']',
+ }));
+ if !self.bump_and_bump_space() {
+ return Err(self.error(
+ Span::new(start, self.pos()),
+ ast::ErrorKind::ClassUnclosed,
+ ));
+ }
+ }
+ let set = ast::ClassBracketed {
+ span: Span::new(start, self.pos()),
+ negated,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: Span::new(union.span.start, union.span.start),
+ items: vec![],
+ }),
+ };
+ Ok((set, union))
+ }
+
+ /// Attempt to parse an ASCII character class, e.g., `[:alnum:]`.
+ ///
+ /// This assumes the parser is positioned at the opening `[`.
+ ///
+ /// If no valid ASCII character class could be found, then this does not
+ /// advance the parser and `None` is returned. Otherwise, the parser is
+ /// advanced to the first byte following the closing `]` and the
+ /// corresponding ASCII class is returned.
+ #[inline(never)]
+ fn maybe_parse_ascii_class(&self) -> Option<ast::ClassAscii> {
+ // ASCII character classes are interesting from a parsing perspective
+ // because parsing cannot fail with any interesting error. For example,
+ // in order to use an ASCII character class, it must be enclosed in
+ // double brackets, e.g., `[[:alnum:]]`. Alternatively, you might think
+ // of it as "ASCII character characters have the syntax `[:NAME:]`
+ // which can only appear within character brackets." This means that
+ // things like `[[:lower:]A]` are legal constructs.
+ //
+ // However, if one types an incorrect ASCII character class, e.g.,
+ // `[[:loower:]]`, then we treat that as a normal nested character
+ // class containing the characters `:elorw`. One might argue that we
+ // should return an error instead since the repeated colons give away
+ // the intent to write an ASCII class. But what if the user typed
+ // `[[:lower]]` instead? How can we tell that was intended to be an
+ // ASCII class and not just a normal nested class?
+ //
+ // Reasonable people can probably disagree over this, but for better
+ // or worse, we implement semantics that never fails at the expense
+ // of better failure modes.
+ assert_eq!(self.char(), '[');
+ // If parsing fails, then we back up the parser to this starting point.
+ let start = self.pos();
+ let mut negated = false;
+ if !self.bump() || self.char() != ':' {
+ self.parser().pos.set(start);
+ return None;
+ }
+ if !self.bump() {
+ self.parser().pos.set(start);
+ return None;
+ }
+ if self.char() == '^' {
+ negated = true;
+ if !self.bump() {
+ self.parser().pos.set(start);
+ return None;
+ }
+ }
+ let name_start = self.offset();
+ while self.char() != ':' && self.bump() {}
+ if self.is_eof() {
+ self.parser().pos.set(start);
+ return None;
+ }
+ let name = &self.pattern()[name_start..self.offset()];
+ if !self.bump_if(":]") {
+ self.parser().pos.set(start);
+ return None;
+ }
+ let kind = match ast::ClassAsciiKind::from_name(name) {
+ Some(kind) => kind,
+ None => {
+ self.parser().pos.set(start);
+ return None;
+ }
+ };
+ Some(ast::ClassAscii {
+ span: Span::new(start, self.pos()),
+ kind,
+ negated,
+ })
+ }
+
+ /// Parse a Unicode class in either the single character notation, `\pN`
+ /// or the multi-character bracketed notation, `\p{Greek}`. This assumes
+ /// the parser is positioned at the `p` (or `P` for negation) and will
+ /// advance the parser to the character immediately following the class.
+ ///
+ /// Note that this does not check whether the class name is valid or not.
+ #[inline(never)]
+ fn parse_unicode_class(&self) -> Result<ast::ClassUnicode> {
+ assert!(self.char() == 'p' || self.char() == 'P');
+
+ let mut scratch = self.parser().scratch.borrow_mut();
+ scratch.clear();
+
+ let negated = self.char() == 'P';
+ if !self.bump_and_bump_space() {
+ return Err(
+ self.error(self.span(), ast::ErrorKind::EscapeUnexpectedEof)
+ );
+ }
+ let (start, kind) = if self.char() == '{' {
+ let start = self.span_char().end;
+ while self.bump_and_bump_space() && self.char() != '}' {
+ scratch.push(self.char());
+ }
+ if self.is_eof() {
+ return Err(self
+ .error(self.span(), ast::ErrorKind::EscapeUnexpectedEof));
+ }
+ assert_eq!(self.char(), '}');
+ self.bump();
+
+ let name = scratch.as_str();
+ if let Some(i) = name.find("!=") {
+ (
+ start,
+ ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::NotEqual,
+ name: name[..i].to_string(),
+ value: name[i + 2..].to_string(),
+ },
+ )
+ } else if let Some(i) = name.find(':') {
+ (
+ start,
+ ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Colon,
+ name: name[..i].to_string(),
+ value: name[i + 1..].to_string(),
+ },
+ )
+ } else if let Some(i) = name.find('=') {
+ (
+ start,
+ ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Equal,
+ name: name[..i].to_string(),
+ value: name[i + 1..].to_string(),
+ },
+ )
+ } else {
+ (start, ast::ClassUnicodeKind::Named(name.to_string()))
+ }
+ } else {
+ let start = self.pos();
+ let c = self.char();
+ if c == '\\' {
+ return Err(self.error(
+ self.span_char(),
+ ast::ErrorKind::UnicodeClassInvalid,
+ ));
+ }
+ self.bump_and_bump_space();
+ let kind = ast::ClassUnicodeKind::OneLetter(c);
+ (start, kind)
+ };
+ Ok(ast::ClassUnicode {
+ span: Span::new(start, self.pos()),
+ negated,
+ kind,
+ })
+ }
+
+ /// Parse a Perl character class, e.g., `\d` or `\W`. This assumes the
+ /// parser is currently at a valid character class name and will be
+ /// advanced to the character immediately following the class.
+ #[inline(never)]
+ fn parse_perl_class(&self) -> ast::ClassPerl {
+ let c = self.char();
+ let span = self.span_char();
+ self.bump();
+ let (negated, kind) = match c {
+ 'd' => (false, ast::ClassPerlKind::Digit),
+ 'D' => (true, ast::ClassPerlKind::Digit),
+ 's' => (false, ast::ClassPerlKind::Space),
+ 'S' => (true, ast::ClassPerlKind::Space),
+ 'w' => (false, ast::ClassPerlKind::Word),
+ 'W' => (true, ast::ClassPerlKind::Word),
+ c => panic!("expected valid Perl class but got '{}'", c),
+ };
+ ast::ClassPerl { span, kind, negated }
+ }
+}
+
+/// A type that traverses a fully parsed Ast and checks whether its depth
+/// exceeds the specified nesting limit. If it does, then an error is returned.
+#[derive(Debug)]
+struct NestLimiter<'p, 's, P> {
+ /// The parser that is checking the nest limit.
+ p: &'p ParserI<'s, P>,
+ /// The current depth while walking an Ast.
+ depth: u32,
+}
+
+impl<'p, 's, P: Borrow<Parser>> NestLimiter<'p, 's, P> {
+ fn new(p: &'p ParserI<'s, P>) -> NestLimiter<'p, 's, P> {
+ NestLimiter { p, depth: 0 }
+ }
+
+ #[inline(never)]
+ fn check(self, ast: &Ast) -> Result<()> {
+ ast::visit(ast, self)
+ }
+
+ fn increment_depth(&mut self, span: &Span) -> Result<()> {
+ let new = self.depth.checked_add(1).ok_or_else(|| {
+ self.p.error(
+ span.clone(),
+ ast::ErrorKind::NestLimitExceeded(::std::u32::MAX),
+ )
+ })?;
+ let limit = self.p.parser().nest_limit;
+ if new > limit {
+ return Err(self.p.error(
+ span.clone(),
+ ast::ErrorKind::NestLimitExceeded(limit),
+ ));
+ }
+ self.depth = new;
+ Ok(())
+ }
+
+ fn decrement_depth(&mut self) {
+ // Assuming the correctness of the visitor, this should never drop
+ // below 0.
+ self.depth = self.depth.checked_sub(1).unwrap();
+ }
+}
+
+impl<'p, 's, P: Borrow<Parser>> ast::Visitor for NestLimiter<'p, 's, P> {
+ type Output = ();
+ type Err = ast::Error;
+
+ fn finish(self) -> Result<()> {
+ Ok(())
+ }
+
+ fn visit_pre(&mut self, ast: &Ast) -> Result<()> {
+ let span = match *ast {
+ Ast::Empty(_)
+ | Ast::Flags(_)
+ | Ast::Literal(_)
+ | Ast::Dot(_)
+ | Ast::Assertion(_)
+ | Ast::Class(ast::Class::Unicode(_))
+ | Ast::Class(ast::Class::Perl(_)) => {
+ // These are all base cases, so we don't increment depth.
+ return Ok(());
+ }
+ Ast::Class(ast::Class::Bracketed(ref x)) => &x.span,
+ Ast::Repetition(ref x) => &x.span,
+ Ast::Group(ref x) => &x.span,
+ Ast::Alternation(ref x) => &x.span,
+ Ast::Concat(ref x) => &x.span,
+ };
+ self.increment_depth(span)
+ }
+
+ fn visit_post(&mut self, ast: &Ast) -> Result<()> {
+ match *ast {
+ Ast::Empty(_)
+ | Ast::Flags(_)
+ | Ast::Literal(_)
+ | Ast::Dot(_)
+ | Ast::Assertion(_)
+ | Ast::Class(ast::Class::Unicode(_))
+ | Ast::Class(ast::Class::Perl(_)) => {
+ // These are all base cases, so we don't decrement depth.
+ Ok(())
+ }
+ Ast::Class(ast::Class::Bracketed(_))
+ | Ast::Repetition(_)
+ | Ast::Group(_)
+ | Ast::Alternation(_)
+ | Ast::Concat(_) => {
+ self.decrement_depth();
+ Ok(())
+ }
+ }
+ }
+
+ fn visit_class_set_item_pre(
+ &mut self,
+ ast: &ast::ClassSetItem,
+ ) -> Result<()> {
+ let span = match *ast {
+ ast::ClassSetItem::Empty(_)
+ | ast::ClassSetItem::Literal(_)
+ | ast::ClassSetItem::Range(_)
+ | ast::ClassSetItem::Ascii(_)
+ | ast::ClassSetItem::Unicode(_)
+ | ast::ClassSetItem::Perl(_) => {
+ // These are all base cases, so we don't increment depth.
+ return Ok(());
+ }
+ ast::ClassSetItem::Bracketed(ref x) => &x.span,
+ ast::ClassSetItem::Union(ref x) => &x.span,
+ };
+ self.increment_depth(span)
+ }
+
+ fn visit_class_set_item_post(
+ &mut self,
+ ast: &ast::ClassSetItem,
+ ) -> Result<()> {
+ match *ast {
+ ast::ClassSetItem::Empty(_)
+ | ast::ClassSetItem::Literal(_)
+ | ast::ClassSetItem::Range(_)
+ | ast::ClassSetItem::Ascii(_)
+ | ast::ClassSetItem::Unicode(_)
+ | ast::ClassSetItem::Perl(_) => {
+ // These are all base cases, so we don't decrement depth.
+ Ok(())
+ }
+ ast::ClassSetItem::Bracketed(_) | ast::ClassSetItem::Union(_) => {
+ self.decrement_depth();
+ Ok(())
+ }
+ }
+ }
+
+ fn visit_class_set_binary_op_pre(
+ &mut self,
+ ast: &ast::ClassSetBinaryOp,
+ ) -> Result<()> {
+ self.increment_depth(&ast.span)
+ }
+
+ fn visit_class_set_binary_op_post(
+ &mut self,
+ _ast: &ast::ClassSetBinaryOp,
+ ) -> Result<()> {
+ self.decrement_depth();
+ Ok(())
+ }
+}
+
+/// When the result is an error, transforms the ast::ErrorKind from the source
+/// Result into another one. This function is used to return clearer error
+/// messages when possible.
+fn specialize_err<T>(
+ result: Result<T>,
+ from: ast::ErrorKind,
+ to: ast::ErrorKind,
+) -> Result<T> {
+ if let Err(e) = result {
+ if e.kind == from {
+ Err(ast::Error { kind: to, pattern: e.pattern, span: e.span })
+ } else {
+ Err(e)
+ }
+ } else {
+ result
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use std::ops::Range;
+
+ use super::{Parser, ParserBuilder, ParserI, Primitive};
+ use crate::ast::{self, Ast, Position, Span};
+
+ // Our own assert_eq, which has slightly better formatting (but honestly
+ // still kind of crappy).
+ macro_rules! assert_eq {
+ ($left:expr, $right:expr) => {{
+ match (&$left, &$right) {
+ (left_val, right_val) => {
+ if !(*left_val == *right_val) {
+ panic!(
+ "assertion failed: `(left == right)`\n\n\
+ left: `{:?}`\nright: `{:?}`\n\n",
+ left_val, right_val
+ )
+ }
+ }
+ }
+ }};
+ }
+
+ // We create these errors to compare with real ast::Errors in the tests.
+ // We define equality between TestError and ast::Error to disregard the
+ // pattern string in ast::Error, which is annoying to provide in tests.
+ #[derive(Clone, Debug)]
+ struct TestError {
+ span: Span,
+ kind: ast::ErrorKind,
+ }
+
+ impl PartialEq<ast::Error> for TestError {
+ fn eq(&self, other: &ast::Error) -> bool {
+ self.span == other.span && self.kind == other.kind
+ }
+ }
+
+ impl PartialEq<TestError> for ast::Error {
+ fn eq(&self, other: &TestError) -> bool {
+ self.span == other.span && self.kind == other.kind
+ }
+ }
+
+ fn s(str: &str) -> String {
+ str.to_string()
+ }
+
+ fn parser(pattern: &str) -> ParserI<'_, Parser> {
+ ParserI::new(Parser::new(), pattern)
+ }
+
+ fn parser_octal(pattern: &str) -> ParserI<'_, Parser> {
+ let parser = ParserBuilder::new().octal(true).build();
+ ParserI::new(parser, pattern)
+ }
+
+ fn parser_nest_limit(
+ pattern: &str,
+ nest_limit: u32,
+ ) -> ParserI<'_, Parser> {
+ let p = ParserBuilder::new().nest_limit(nest_limit).build();
+ ParserI::new(p, pattern)
+ }
+
+ fn parser_ignore_whitespace(pattern: &str) -> ParserI<'_, Parser> {
+ let p = ParserBuilder::new().ignore_whitespace(true).build();
+ ParserI::new(p, pattern)
+ }
+
+ /// Short alias for creating a new span.
+ fn nspan(start: Position, end: Position) -> Span {
+ Span::new(start, end)
+ }
+
+ /// Short alias for creating a new position.
+ fn npos(offset: usize, line: usize, column: usize) -> Position {
+ Position::new(offset, line, column)
+ }
+
+ /// Create a new span from the given offset range. This assumes a single
+ /// line and sets the columns based on the offsets. i.e., This only works
+ /// out of the box for ASCII, which is fine for most tests.
+ fn span(range: Range<usize>) -> Span {
+ let start = Position::new(range.start, 1, range.start + 1);
+ let end = Position::new(range.end, 1, range.end + 1);
+ Span::new(start, end)
+ }
+
+ /// Create a new span for the corresponding byte range in the given string.
+ fn span_range(subject: &str, range: Range<usize>) -> Span {
+ let start = Position {
+ offset: range.start,
+ line: 1 + subject[..range.start].matches('\n').count(),
+ column: 1 + subject[..range.start]
+ .chars()
+ .rev()
+ .position(|c| c == '\n')
+ .unwrap_or(subject[..range.start].chars().count()),
+ };
+ let end = Position {
+ offset: range.end,
+ line: 1 + subject[..range.end].matches('\n').count(),
+ column: 1 + subject[..range.end]
+ .chars()
+ .rev()
+ .position(|c| c == '\n')
+ .unwrap_or(subject[..range.end].chars().count()),
+ };
+ Span::new(start, end)
+ }
+
+ /// Create a verbatim literal starting at the given position.
+ fn lit(c: char, start: usize) -> Ast {
+ lit_with(c, span(start..start + c.len_utf8()))
+ }
+
+ /// Create a punctuation literal starting at the given position.
+ fn punct_lit(c: char, span: Span) -> Ast {
+ Ast::Literal(ast::Literal {
+ span,
+ kind: ast::LiteralKind::Punctuation,
+ c,
+ })
+ }
+
+ /// Create a verbatim literal with the given span.
+ fn lit_with(c: char, span: Span) -> Ast {
+ Ast::Literal(ast::Literal {
+ span,
+ kind: ast::LiteralKind::Verbatim,
+ c,
+ })
+ }
+
+ /// Create a concatenation with the given range.
+ fn concat(range: Range<usize>, asts: Vec<Ast>) -> Ast {
+ concat_with(span(range), asts)
+ }
+
+ /// Create a concatenation with the given span.
+ fn concat_with(span: Span, asts: Vec<Ast>) -> Ast {
+ Ast::Concat(ast::Concat { span, asts })
+ }
+
+ /// Create an alternation with the given span.
+ fn alt(range: Range<usize>, asts: Vec<Ast>) -> Ast {
+ Ast::Alternation(ast::Alternation { span: span(range), asts })
+ }
+
+ /// Create a capturing group with the given span.
+ fn group(range: Range<usize>, index: u32, ast: Ast) -> Ast {
+ Ast::Group(ast::Group {
+ span: span(range),
+ kind: ast::GroupKind::CaptureIndex(index),
+ ast: Box::new(ast),
+ })
+ }
+
+ /// Create an ast::SetFlags.
+ ///
+ /// The given pattern should be the full pattern string. The range given
+ /// should correspond to the byte offsets where the flag set occurs.
+ ///
+ /// If negated is true, then the set is interpreted as beginning with a
+ /// negation.
+ fn flag_set(
+ pat: &str,
+ range: Range<usize>,
+ flag: ast::Flag,
+ negated: bool,
+ ) -> Ast {
+ let mut items = vec![ast::FlagsItem {
+ span: span_range(pat, (range.end - 2)..(range.end - 1)),
+ kind: ast::FlagsItemKind::Flag(flag),
+ }];
+ if negated {
+ items.insert(
+ 0,
+ ast::FlagsItem {
+ span: span_range(pat, (range.start + 2)..(range.end - 2)),
+ kind: ast::FlagsItemKind::Negation,
+ },
+ );
+ }
+ Ast::Flags(ast::SetFlags {
+ span: span_range(pat, range.clone()),
+ flags: ast::Flags {
+ span: span_range(pat, (range.start + 2)..(range.end - 1)),
+ items,
+ },
+ })
+ }
+
+ #[test]
+ fn parse_nest_limit() {
+ // A nest limit of 0 still allows some types of regexes.
+ assert_eq!(
+ parser_nest_limit("", 0).parse(),
+ Ok(Ast::Empty(span(0..0)))
+ );
+ assert_eq!(parser_nest_limit("a", 0).parse(), Ok(lit('a', 0)));
+
+ // Test repetition operations, which require one level of nesting.
+ assert_eq!(
+ parser_nest_limit("a+", 0).parse().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::NestLimitExceeded(0),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("a+", 1).parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::OneOrMore,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser_nest_limit("(a)+", 1).parse().unwrap_err(),
+ TestError {
+ span: span(0..3),
+ kind: ast::ErrorKind::NestLimitExceeded(1),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("a+*", 1).parse().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::NestLimitExceeded(1),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("a+*", 2).parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..3),
+ op: ast::RepetitionOp {
+ span: span(2..3),
+ kind: ast::RepetitionKind::ZeroOrMore,
+ },
+ greedy: true,
+ ast: Box::new(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::OneOrMore,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ })),
+ }))
+ );
+
+ // Test concatenations. A concatenation requires one level of nesting.
+ assert_eq!(
+ parser_nest_limit("ab", 0).parse().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::NestLimitExceeded(0),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("ab", 1).parse(),
+ Ok(concat(0..2, vec![lit('a', 0), lit('b', 1)]))
+ );
+ assert_eq!(
+ parser_nest_limit("abc", 1).parse(),
+ Ok(concat(0..3, vec![lit('a', 0), lit('b', 1), lit('c', 2)]))
+ );
+
+ // Test alternations. An alternation requires one level of nesting.
+ assert_eq!(
+ parser_nest_limit("a|b", 0).parse().unwrap_err(),
+ TestError {
+ span: span(0..3),
+ kind: ast::ErrorKind::NestLimitExceeded(0),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("a|b", 1).parse(),
+ Ok(alt(0..3, vec![lit('a', 0), lit('b', 2)]))
+ );
+ assert_eq!(
+ parser_nest_limit("a|b|c", 1).parse(),
+ Ok(alt(0..5, vec![lit('a', 0), lit('b', 2), lit('c', 4)]))
+ );
+
+ // Test character classes. Classes form their own mini-recursive
+ // syntax!
+ assert_eq!(
+ parser_nest_limit("[a]", 0).parse().unwrap_err(),
+ TestError {
+ span: span(0..3),
+ kind: ast::ErrorKind::NestLimitExceeded(0),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("[a]", 1).parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..3),
+ negated: false,
+ kind: ast::ClassSet::Item(ast::ClassSetItem::Literal(
+ ast::Literal {
+ span: span(1..2),
+ kind: ast::LiteralKind::Verbatim,
+ c: 'a',
+ }
+ )),
+ })))
+ );
+ assert_eq!(
+ parser_nest_limit("[ab]", 1).parse().unwrap_err(),
+ TestError {
+ span: span(1..3),
+ kind: ast::ErrorKind::NestLimitExceeded(1),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("[ab[cd]]", 2).parse().unwrap_err(),
+ TestError {
+ span: span(3..7),
+ kind: ast::ErrorKind::NestLimitExceeded(2),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("[ab[cd]]", 3).parse().unwrap_err(),
+ TestError {
+ span: span(4..6),
+ kind: ast::ErrorKind::NestLimitExceeded(3),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("[a--b]", 1).parse().unwrap_err(),
+ TestError {
+ span: span(1..5),
+ kind: ast::ErrorKind::NestLimitExceeded(1),
+ }
+ );
+ assert_eq!(
+ parser_nest_limit("[a--bc]", 2).parse().unwrap_err(),
+ TestError {
+ span: span(4..6),
+ kind: ast::ErrorKind::NestLimitExceeded(2),
+ }
+ );
+ }
+
+ #[test]
+ fn parse_comments() {
+ let pat = "(?x)
+# This is comment 1.
+foo # This is comment 2.
+ # This is comment 3.
+bar
+# This is comment 4.";
+ let astc = parser(pat).parse_with_comments().unwrap();
+ assert_eq!(
+ astc.ast,
+ concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ lit_with('f', span_range(pat, 26..27)),
+ lit_with('o', span_range(pat, 27..28)),
+ lit_with('o', span_range(pat, 28..29)),
+ lit_with('b', span_range(pat, 74..75)),
+ lit_with('a', span_range(pat, 75..76)),
+ lit_with('r', span_range(pat, 76..77)),
+ ]
+ )
+ );
+ assert_eq!(
+ astc.comments,
+ vec![
+ ast::Comment {
+ span: span_range(pat, 5..26),
+ comment: s(" This is comment 1."),
+ },
+ ast::Comment {
+ span: span_range(pat, 30..51),
+ comment: s(" This is comment 2."),
+ },
+ ast::Comment {
+ span: span_range(pat, 53..74),
+ comment: s(" This is comment 3."),
+ },
+ ast::Comment {
+ span: span_range(pat, 78..98),
+ comment: s(" This is comment 4."),
+ },
+ ]
+ );
+ }
+
+ #[test]
+ fn parse_holistic() {
+ assert_eq!(parser("]").parse(), Ok(lit(']', 0)));
+ assert_eq!(
+ parser(r"\\\.\+\*\?\(\)\|\[\]\{\}\^\$\#\&\-\~").parse(),
+ Ok(concat(
+ 0..36,
+ vec![
+ punct_lit('\\', span(0..2)),
+ punct_lit('.', span(2..4)),
+ punct_lit('+', span(4..6)),
+ punct_lit('*', span(6..8)),
+ punct_lit('?', span(8..10)),
+ punct_lit('(', span(10..12)),
+ punct_lit(')', span(12..14)),
+ punct_lit('|', span(14..16)),
+ punct_lit('[', span(16..18)),
+ punct_lit(']', span(18..20)),
+ punct_lit('{', span(20..22)),
+ punct_lit('}', span(22..24)),
+ punct_lit('^', span(24..26)),
+ punct_lit('$', span(26..28)),
+ punct_lit('#', span(28..30)),
+ punct_lit('&', span(30..32)),
+ punct_lit('-', span(32..34)),
+ punct_lit('~', span(34..36)),
+ ]
+ ))
+ );
+ }
+
+ #[test]
+ fn parse_ignore_whitespace() {
+ // Test that basic whitespace insensitivity works.
+ let pat = "(?x)a b";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ nspan(npos(0, 1, 1), npos(7, 1, 8)),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ lit_with('a', nspan(npos(4, 1, 5), npos(5, 1, 6))),
+ lit_with('b', nspan(npos(6, 1, 7), npos(7, 1, 8))),
+ ]
+ ))
+ );
+
+ // Test that we can toggle whitespace insensitivity.
+ let pat = "(?x)a b(?-x)a b";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ nspan(npos(0, 1, 1), npos(15, 1, 16)),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ lit_with('a', nspan(npos(4, 1, 5), npos(5, 1, 6))),
+ lit_with('b', nspan(npos(6, 1, 7), npos(7, 1, 8))),
+ flag_set(pat, 7..12, ast::Flag::IgnoreWhitespace, true),
+ lit_with('a', nspan(npos(12, 1, 13), npos(13, 1, 14))),
+ lit_with(' ', nspan(npos(13, 1, 14), npos(14, 1, 15))),
+ lit_with('b', nspan(npos(14, 1, 15), npos(15, 1, 16))),
+ ]
+ ))
+ );
+
+ // Test that nesting whitespace insensitive flags works.
+ let pat = "a (?x:a )a ";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..11),
+ vec![
+ lit_with('a', span_range(pat, 0..1)),
+ lit_with(' ', span_range(pat, 1..2)),
+ Ast::Group(ast::Group {
+ span: span_range(pat, 2..9),
+ kind: ast::GroupKind::NonCapturing(ast::Flags {
+ span: span_range(pat, 4..5),
+ items: vec![ast::FlagsItem {
+ span: span_range(pat, 4..5),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::IgnoreWhitespace
+ ),
+ },],
+ }),
+ ast: Box::new(lit_with('a', span_range(pat, 6..7))),
+ }),
+ lit_with('a', span_range(pat, 9..10)),
+ lit_with(' ', span_range(pat, 10..11)),
+ ]
+ ))
+ );
+
+ // Test that whitespace after an opening paren is insignificant.
+ let pat = "(?x)( ?P<foo> a )";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ Ast::Group(ast::Group {
+ span: span_range(pat, 4..pat.len()),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span_range(pat, 9..12),
+ name: s("foo"),
+ index: 1,
+ }),
+ ast: Box::new(lit_with('a', span_range(pat, 14..15))),
+ }),
+ ]
+ ))
+ );
+ let pat = "(?x)( a )";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ Ast::Group(ast::Group {
+ span: span_range(pat, 4..pat.len()),
+ kind: ast::GroupKind::CaptureIndex(1),
+ ast: Box::new(lit_with('a', span_range(pat, 7..8))),
+ }),
+ ]
+ ))
+ );
+ let pat = "(?x)( ?: a )";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ Ast::Group(ast::Group {
+ span: span_range(pat, 4..pat.len()),
+ kind: ast::GroupKind::NonCapturing(ast::Flags {
+ span: span_range(pat, 8..8),
+ items: vec![],
+ }),
+ ast: Box::new(lit_with('a', span_range(pat, 11..12))),
+ }),
+ ]
+ ))
+ );
+ let pat = r"(?x)\x { 53 }";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ Ast::Literal(ast::Literal {
+ span: span(4..13),
+ kind: ast::LiteralKind::HexBrace(
+ ast::HexLiteralKind::X
+ ),
+ c: 'S',
+ }),
+ ]
+ ))
+ );
+
+ // Test that whitespace after an escape is OK.
+ let pat = r"(?x)\ ";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ flag_set(pat, 0..4, ast::Flag::IgnoreWhitespace, false),
+ Ast::Literal(ast::Literal {
+ span: span_range(pat, 4..6),
+ kind: ast::LiteralKind::Special(
+ ast::SpecialLiteralKind::Space
+ ),
+ c: ' ',
+ }),
+ ]
+ ))
+ );
+ // ... but only when `x` mode is enabled.
+ let pat = r"\ ";
+ assert_eq!(
+ parser(pat).parse().unwrap_err(),
+ TestError {
+ span: span_range(pat, 0..2),
+ kind: ast::ErrorKind::EscapeUnrecognized,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_newlines() {
+ let pat = ".\n.";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..3),
+ vec![
+ Ast::Dot(span_range(pat, 0..1)),
+ lit_with('\n', span_range(pat, 1..2)),
+ Ast::Dot(span_range(pat, 2..3)),
+ ]
+ ))
+ );
+
+ let pat = "foobar\nbaz\nquux\n";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(concat_with(
+ span_range(pat, 0..pat.len()),
+ vec![
+ lit_with('f', nspan(npos(0, 1, 1), npos(1, 1, 2))),
+ lit_with('o', nspan(npos(1, 1, 2), npos(2, 1, 3))),
+ lit_with('o', nspan(npos(2, 1, 3), npos(3, 1, 4))),
+ lit_with('b', nspan(npos(3, 1, 4), npos(4, 1, 5))),
+ lit_with('a', nspan(npos(4, 1, 5), npos(5, 1, 6))),
+ lit_with('r', nspan(npos(5, 1, 6), npos(6, 1, 7))),
+ lit_with('\n', nspan(npos(6, 1, 7), npos(7, 2, 1))),
+ lit_with('b', nspan(npos(7, 2, 1), npos(8, 2, 2))),
+ lit_with('a', nspan(npos(8, 2, 2), npos(9, 2, 3))),
+ lit_with('z', nspan(npos(9, 2, 3), npos(10, 2, 4))),
+ lit_with('\n', nspan(npos(10, 2, 4), npos(11, 3, 1))),
+ lit_with('q', nspan(npos(11, 3, 1), npos(12, 3, 2))),
+ lit_with('u', nspan(npos(12, 3, 2), npos(13, 3, 3))),
+ lit_with('u', nspan(npos(13, 3, 3), npos(14, 3, 4))),
+ lit_with('x', nspan(npos(14, 3, 4), npos(15, 3, 5))),
+ lit_with('\n', nspan(npos(15, 3, 5), npos(16, 4, 1))),
+ ]
+ ))
+ );
+ }
+
+ #[test]
+ fn parse_uncounted_repetition() {
+ assert_eq!(
+ parser(r"a*").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::ZeroOrMore,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a+").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::OneOrMore,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+
+ assert_eq!(
+ parser(r"a?").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a??").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..3),
+ op: ast::RepetitionOp {
+ span: span(1..3),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: false,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a?").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a?b").parse(),
+ Ok(concat(
+ 0..3,
+ vec![
+ Ast::Repetition(ast::Repetition {
+ span: span(0..2),
+ op: ast::RepetitionOp {
+ span: span(1..2),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }),
+ lit('b', 2),
+ ]
+ ))
+ );
+ assert_eq!(
+ parser(r"a??b").parse(),
+ Ok(concat(
+ 0..4,
+ vec![
+ Ast::Repetition(ast::Repetition {
+ span: span(0..3),
+ op: ast::RepetitionOp {
+ span: span(1..3),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: false,
+ ast: Box::new(lit('a', 0)),
+ }),
+ lit('b', 3),
+ ]
+ ))
+ );
+ assert_eq!(
+ parser(r"ab?").parse(),
+ Ok(concat(
+ 0..3,
+ vec![
+ lit('a', 0),
+ Ast::Repetition(ast::Repetition {
+ span: span(1..3),
+ op: ast::RepetitionOp {
+ span: span(2..3),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(lit('b', 1)),
+ }),
+ ]
+ ))
+ );
+ assert_eq!(
+ parser(r"(ab)?").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..5),
+ op: ast::RepetitionOp {
+ span: span(4..5),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(group(
+ 0..4,
+ 1,
+ concat(1..3, vec![lit('a', 1), lit('b', 2),])
+ )),
+ }))
+ );
+ assert_eq!(
+ parser(r"|a?").parse(),
+ Ok(alt(
+ 0..3,
+ vec![
+ Ast::Empty(span(0..0)),
+ Ast::Repetition(ast::Repetition {
+ span: span(1..3),
+ op: ast::RepetitionOp {
+ span: span(2..3),
+ kind: ast::RepetitionKind::ZeroOrOne,
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 1)),
+ }),
+ ]
+ ))
+ );
+
+ assert_eq!(
+ parser(r"*").parse().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"(?i)*").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"(*)").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"(?:?)").parse().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"+").parse().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"?").parse().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"(?)").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"|*").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"|+").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"|?").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_counted_repetition() {
+ assert_eq!(
+ parser(r"a{5}").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..4),
+ op: ast::RepetitionOp {
+ span: span(1..4),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Exactly(5)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a{5,}").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..5),
+ op: ast::RepetitionOp {
+ span: span(1..5),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::AtLeast(5)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a{5,9}").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..6),
+ op: ast::RepetitionOp {
+ span: span(1..6),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Bounded(5, 9)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a{5}?").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..5),
+ op: ast::RepetitionOp {
+ span: span(1..5),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Exactly(5)
+ ),
+ },
+ greedy: false,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"ab{5}").parse(),
+ Ok(concat(
+ 0..5,
+ vec![
+ lit('a', 0),
+ Ast::Repetition(ast::Repetition {
+ span: span(1..5),
+ op: ast::RepetitionOp {
+ span: span(2..5),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Exactly(5)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('b', 1)),
+ }),
+ ]
+ ))
+ );
+ assert_eq!(
+ parser(r"ab{5}c").parse(),
+ Ok(concat(
+ 0..6,
+ vec![
+ lit('a', 0),
+ Ast::Repetition(ast::Repetition {
+ span: span(1..5),
+ op: ast::RepetitionOp {
+ span: span(2..5),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Exactly(5)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('b', 1)),
+ }),
+ lit('c', 5),
+ ]
+ ))
+ );
+
+ assert_eq!(
+ parser(r"a{ 5 }").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..6),
+ op: ast::RepetitionOp {
+ span: span(1..6),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Exactly(5)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser(r"a{ 5 , 9 }").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..10),
+ op: ast::RepetitionOp {
+ span: span(1..10),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Bounded(5, 9)
+ ),
+ },
+ greedy: true,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+ assert_eq!(
+ parser_ignore_whitespace(r"a{5,9} ?").parse(),
+ Ok(Ast::Repetition(ast::Repetition {
+ span: span(0..8),
+ op: ast::RepetitionOp {
+ span: span(1..8),
+ kind: ast::RepetitionKind::Range(
+ ast::RepetitionRange::Bounded(5, 9)
+ ),
+ },
+ greedy: false,
+ ast: Box::new(lit('a', 0)),
+ }))
+ );
+
+ assert_eq!(
+ parser(r"(?i){0}").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"(?m){1,1}").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"a{]}").parse().unwrap_err(),
+ TestError {
+ span: span(2..2),
+ kind: ast::ErrorKind::RepetitionCountDecimalEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"a{1,]}").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::RepetitionCountDecimalEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"a{").parse().unwrap_err(),
+ TestError {
+ span: span(1..2),
+ kind: ast::ErrorKind::RepetitionCountUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(r"a{}").parse().unwrap_err(),
+ TestError {
+ span: span(2..2),
+ kind: ast::ErrorKind::RepetitionCountDecimalEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"a{a").parse().unwrap_err(),
+ TestError {
+ span: span(2..2),
+ kind: ast::ErrorKind::RepetitionCountDecimalEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9999999999}").parse().unwrap_err(),
+ TestError {
+ span: span(2..12),
+ kind: ast::ErrorKind::DecimalInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9").parse().unwrap_err(),
+ TestError {
+ span: span(1..3),
+ kind: ast::ErrorKind::RepetitionCountUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9,a").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::RepetitionCountDecimalEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9,9999999999}").parse().unwrap_err(),
+ TestError {
+ span: span(4..14),
+ kind: ast::ErrorKind::DecimalInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9,").parse().unwrap_err(),
+ TestError {
+ span: span(1..4),
+ kind: ast::ErrorKind::RepetitionCountUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(r"a{9,11").parse().unwrap_err(),
+ TestError {
+ span: span(1..6),
+ kind: ast::ErrorKind::RepetitionCountUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(r"a{2,1}").parse().unwrap_err(),
+ TestError {
+ span: span(1..6),
+ kind: ast::ErrorKind::RepetitionCountInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"{5}").parse().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ assert_eq!(
+ parser(r"|{5}").parse().unwrap_err(),
+ TestError {
+ span: span(1..1),
+ kind: ast::ErrorKind::RepetitionMissing,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_alternate() {
+ assert_eq!(
+ parser(r"a|b").parse(),
+ Ok(Ast::Alternation(ast::Alternation {
+ span: span(0..3),
+ asts: vec![lit('a', 0), lit('b', 2)],
+ }))
+ );
+ assert_eq!(
+ parser(r"(a|b)").parse(),
+ Ok(group(
+ 0..5,
+ 1,
+ Ast::Alternation(ast::Alternation {
+ span: span(1..4),
+ asts: vec![lit('a', 1), lit('b', 3)],
+ })
+ ))
+ );
+
+ assert_eq!(
+ parser(r"a|b|c").parse(),
+ Ok(Ast::Alternation(ast::Alternation {
+ span: span(0..5),
+ asts: vec![lit('a', 0), lit('b', 2), lit('c', 4)],
+ }))
+ );
+ assert_eq!(
+ parser(r"ax|by|cz").parse(),
+ Ok(Ast::Alternation(ast::Alternation {
+ span: span(0..8),
+ asts: vec![
+ concat(0..2, vec![lit('a', 0), lit('x', 1)]),
+ concat(3..5, vec![lit('b', 3), lit('y', 4)]),
+ concat(6..8, vec![lit('c', 6), lit('z', 7)]),
+ ],
+ }))
+ );
+ assert_eq!(
+ parser(r"(ax|by|cz)").parse(),
+ Ok(group(
+ 0..10,
+ 1,
+ Ast::Alternation(ast::Alternation {
+ span: span(1..9),
+ asts: vec![
+ concat(1..3, vec![lit('a', 1), lit('x', 2)]),
+ concat(4..6, vec![lit('b', 4), lit('y', 5)]),
+ concat(7..9, vec![lit('c', 7), lit('z', 8)]),
+ ],
+ })
+ ))
+ );
+ assert_eq!(
+ parser(r"(ax|(by|(cz)))").parse(),
+ Ok(group(
+ 0..14,
+ 1,
+ alt(
+ 1..13,
+ vec![
+ concat(1..3, vec![lit('a', 1), lit('x', 2)]),
+ group(
+ 4..13,
+ 2,
+ alt(
+ 5..12,
+ vec![
+ concat(
+ 5..7,
+ vec![lit('b', 5), lit('y', 6)]
+ ),
+ group(
+ 8..12,
+ 3,
+ concat(
+ 9..11,
+ vec![lit('c', 9), lit('z', 10),]
+ )
+ ),
+ ]
+ )
+ ),
+ ]
+ )
+ ))
+ );
+
+ assert_eq!(
+ parser(r"|").parse(),
+ Ok(alt(
+ 0..1,
+ vec![Ast::Empty(span(0..0)), Ast::Empty(span(1..1)),]
+ ))
+ );
+ assert_eq!(
+ parser(r"||").parse(),
+ Ok(alt(
+ 0..2,
+ vec![
+ Ast::Empty(span(0..0)),
+ Ast::Empty(span(1..1)),
+ Ast::Empty(span(2..2)),
+ ]
+ ))
+ );
+ assert_eq!(
+ parser(r"a|").parse(),
+ Ok(alt(0..2, vec![lit('a', 0), Ast::Empty(span(2..2)),]))
+ );
+ assert_eq!(
+ parser(r"|a").parse(),
+ Ok(alt(0..2, vec![Ast::Empty(span(0..0)), lit('a', 1),]))
+ );
+
+ assert_eq!(
+ parser(r"(|)").parse(),
+ Ok(group(
+ 0..3,
+ 1,
+ alt(
+ 1..2,
+ vec![Ast::Empty(span(1..1)), Ast::Empty(span(2..2)),]
+ )
+ ))
+ );
+ assert_eq!(
+ parser(r"(a|)").parse(),
+ Ok(group(
+ 0..4,
+ 1,
+ alt(1..3, vec![lit('a', 1), Ast::Empty(span(3..3)),])
+ ))
+ );
+ assert_eq!(
+ parser(r"(|a)").parse(),
+ Ok(group(
+ 0..4,
+ 1,
+ alt(1..3, vec![Ast::Empty(span(1..1)), lit('a', 2),])
+ ))
+ );
+
+ assert_eq!(
+ parser(r"a|b)").parse().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::GroupUnopened,
+ }
+ );
+ assert_eq!(
+ parser(r"(a|b").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnclosed,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_unsupported_lookaround() {
+ assert_eq!(
+ parser(r"(?=a)").parse().unwrap_err(),
+ TestError {
+ span: span(0..3),
+ kind: ast::ErrorKind::UnsupportedLookAround,
+ }
+ );
+ assert_eq!(
+ parser(r"(?!a)").parse().unwrap_err(),
+ TestError {
+ span: span(0..3),
+ kind: ast::ErrorKind::UnsupportedLookAround,
+ }
+ );
+ assert_eq!(
+ parser(r"(?<=a)").parse().unwrap_err(),
+ TestError {
+ span: span(0..4),
+ kind: ast::ErrorKind::UnsupportedLookAround,
+ }
+ );
+ assert_eq!(
+ parser(r"(?<!a)").parse().unwrap_err(),
+ TestError {
+ span: span(0..4),
+ kind: ast::ErrorKind::UnsupportedLookAround,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_group() {
+ assert_eq!(
+ parser("(?i)").parse(),
+ Ok(Ast::Flags(ast::SetFlags {
+ span: span(0..4),
+ flags: ast::Flags {
+ span: span(2..3),
+ items: vec![ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ }],
+ },
+ }))
+ );
+ assert_eq!(
+ parser("(?iU)").parse(),
+ Ok(Ast::Flags(ast::SetFlags {
+ span: span(0..5),
+ flags: ast::Flags {
+ span: span(2..4),
+ items: vec![
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(3..4),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::SwapGreed
+ ),
+ },
+ ],
+ },
+ }))
+ );
+ assert_eq!(
+ parser("(?i-U)").parse(),
+ Ok(Ast::Flags(ast::SetFlags {
+ span: span(0..6),
+ flags: ast::Flags {
+ span: span(2..5),
+ items: vec![
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(3..4),
+ kind: ast::FlagsItemKind::Negation,
+ },
+ ast::FlagsItem {
+ span: span(4..5),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::SwapGreed
+ ),
+ },
+ ],
+ },
+ }))
+ );
+
+ assert_eq!(
+ parser("()").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..2),
+ kind: ast::GroupKind::CaptureIndex(1),
+ ast: Box::new(Ast::Empty(span(1..1))),
+ }))
+ );
+ assert_eq!(
+ parser("(a)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..3),
+ kind: ast::GroupKind::CaptureIndex(1),
+ ast: Box::new(lit('a', 1)),
+ }))
+ );
+ assert_eq!(
+ parser("(())").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..4),
+ kind: ast::GroupKind::CaptureIndex(1),
+ ast: Box::new(Ast::Group(ast::Group {
+ span: span(1..3),
+ kind: ast::GroupKind::CaptureIndex(2),
+ ast: Box::new(Ast::Empty(span(2..2))),
+ })),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?:a)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..5),
+ kind: ast::GroupKind::NonCapturing(ast::Flags {
+ span: span(2..2),
+ items: vec![],
+ }),
+ ast: Box::new(lit('a', 3)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?i:a)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..6),
+ kind: ast::GroupKind::NonCapturing(ast::Flags {
+ span: span(2..3),
+ items: vec![ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },],
+ }),
+ ast: Box::new(lit('a', 4)),
+ }))
+ );
+ assert_eq!(
+ parser("(?i-U:a)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..8),
+ kind: ast::GroupKind::NonCapturing(ast::Flags {
+ span: span(2..5),
+ items: vec![
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(3..4),
+ kind: ast::FlagsItemKind::Negation,
+ },
+ ast::FlagsItem {
+ span: span(4..5),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::SwapGreed
+ ),
+ },
+ ],
+ }),
+ ast: Box::new(lit('a', 6)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("(?").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("(?P").parse().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::FlagUnrecognized,
+ }
+ );
+ assert_eq!(
+ parser("(?P<").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::GroupNameUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser("(a").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("(()").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(")").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::GroupUnopened,
+ }
+ );
+ assert_eq!(
+ parser("a)").parse().unwrap_err(),
+ TestError {
+ span: span(1..2),
+ kind: ast::ErrorKind::GroupUnopened,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_capture_name() {
+ assert_eq!(
+ parser("(?P<a>z)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..8),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span(4..5),
+ name: s("a"),
+ index: 1,
+ }),
+ ast: Box::new(lit('z', 6)),
+ }))
+ );
+ assert_eq!(
+ parser("(?P<abc>z)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..10),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span(4..7),
+ name: s("abc"),
+ index: 1,
+ }),
+ ast: Box::new(lit('z', 8)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?P<a_1>z)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..10),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span(4..7),
+ name: s("a_1"),
+ index: 1,
+ }),
+ ast: Box::new(lit('z', 8)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?P<a.1>z)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..10),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span(4..7),
+ name: s("a.1"),
+ index: 1,
+ }),
+ ast: Box::new(lit('z', 8)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?P<a[1]>z)").parse(),
+ Ok(Ast::Group(ast::Group {
+ span: span(0..11),
+ kind: ast::GroupKind::CaptureName(ast::CaptureName {
+ span: span(4..8),
+ name: s("a[1]"),
+ index: 1,
+ }),
+ ast: Box::new(lit('z', 9)),
+ }))
+ );
+
+ assert_eq!(
+ parser("(?P<").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::GroupNameUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser("(?P<>z)").parse().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::GroupNameEmpty,
+ }
+ );
+ assert_eq!(
+ parser("(?P<a").parse().unwrap_err(),
+ TestError {
+ span: span(5..5),
+ kind: ast::ErrorKind::GroupNameUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser("(?P<ab").parse().unwrap_err(),
+ TestError {
+ span: span(6..6),
+ kind: ast::ErrorKind::GroupNameUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser("(?P<0a").parse().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::GroupNameInvalid,
+ }
+ );
+ assert_eq!(
+ parser("(?P<~").parse().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::GroupNameInvalid,
+ }
+ );
+ assert_eq!(
+ parser("(?P<abc~").parse().unwrap_err(),
+ TestError {
+ span: span(7..8),
+ kind: ast::ErrorKind::GroupNameInvalid,
+ }
+ );
+ assert_eq!(
+ parser("(?P<a>y)(?P<a>z)").parse().unwrap_err(),
+ TestError {
+ span: span(12..13),
+ kind: ast::ErrorKind::GroupNameDuplicate {
+ original: span(4..5),
+ },
+ }
+ );
+ }
+
+ #[test]
+ fn parse_flags() {
+ assert_eq!(
+ parser("i:").parse_flags(),
+ Ok(ast::Flags {
+ span: span(0..1),
+ items: vec![ast::FlagsItem {
+ span: span(0..1),
+ kind: ast::FlagsItemKind::Flag(ast::Flag::CaseInsensitive),
+ }],
+ })
+ );
+ assert_eq!(
+ parser("i)").parse_flags(),
+ Ok(ast::Flags {
+ span: span(0..1),
+ items: vec![ast::FlagsItem {
+ span: span(0..1),
+ kind: ast::FlagsItemKind::Flag(ast::Flag::CaseInsensitive),
+ }],
+ })
+ );
+
+ assert_eq!(
+ parser("isU:").parse_flags(),
+ Ok(ast::Flags {
+ span: span(0..3),
+ items: vec![
+ ast::FlagsItem {
+ span: span(0..1),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(1..2),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::DotMatchesNewLine
+ ),
+ },
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(ast::Flag::SwapGreed),
+ },
+ ],
+ })
+ );
+
+ assert_eq!(
+ parser("-isU:").parse_flags(),
+ Ok(ast::Flags {
+ span: span(0..4),
+ items: vec![
+ ast::FlagsItem {
+ span: span(0..1),
+ kind: ast::FlagsItemKind::Negation,
+ },
+ ast::FlagsItem {
+ span: span(1..2),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::DotMatchesNewLine
+ ),
+ },
+ ast::FlagsItem {
+ span: span(3..4),
+ kind: ast::FlagsItemKind::Flag(ast::Flag::SwapGreed),
+ },
+ ],
+ })
+ );
+ assert_eq!(
+ parser("i-sU:").parse_flags(),
+ Ok(ast::Flags {
+ span: span(0..4),
+ items: vec![
+ ast::FlagsItem {
+ span: span(0..1),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::CaseInsensitive
+ ),
+ },
+ ast::FlagsItem {
+ span: span(1..2),
+ kind: ast::FlagsItemKind::Negation,
+ },
+ ast::FlagsItem {
+ span: span(2..3),
+ kind: ast::FlagsItemKind::Flag(
+ ast::Flag::DotMatchesNewLine
+ ),
+ },
+ ast::FlagsItem {
+ span: span(3..4),
+ kind: ast::FlagsItemKind::Flag(ast::Flag::SwapGreed),
+ },
+ ],
+ })
+ );
+
+ assert_eq!(
+ parser("isU").parse_flags().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::FlagUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser("isUa:").parse_flags().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::FlagUnrecognized,
+ }
+ );
+ assert_eq!(
+ parser("isUi:").parse_flags().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::FlagDuplicate { original: span(0..1) },
+ }
+ );
+ assert_eq!(
+ parser("i-sU-i:").parse_flags().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::FlagRepeatedNegation {
+ original: span(1..2),
+ },
+ }
+ );
+ assert_eq!(
+ parser("-)").parse_flags().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::FlagDanglingNegation,
+ }
+ );
+ assert_eq!(
+ parser("i-)").parse_flags().unwrap_err(),
+ TestError {
+ span: span(1..2),
+ kind: ast::ErrorKind::FlagDanglingNegation,
+ }
+ );
+ assert_eq!(
+ parser("iU-)").parse_flags().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::FlagDanglingNegation,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_flag() {
+ assert_eq!(parser("i").parse_flag(), Ok(ast::Flag::CaseInsensitive));
+ assert_eq!(parser("m").parse_flag(), Ok(ast::Flag::MultiLine));
+ assert_eq!(parser("s").parse_flag(), Ok(ast::Flag::DotMatchesNewLine));
+ assert_eq!(parser("U").parse_flag(), Ok(ast::Flag::SwapGreed));
+ assert_eq!(parser("u").parse_flag(), Ok(ast::Flag::Unicode));
+ assert_eq!(parser("x").parse_flag(), Ok(ast::Flag::IgnoreWhitespace));
+
+ assert_eq!(
+ parser("a").parse_flag().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::FlagUnrecognized,
+ }
+ );
+ assert_eq!(
+ parser("☃").parse_flag().unwrap_err(),
+ TestError {
+ span: span_range("☃", 0..3),
+ kind: ast::ErrorKind::FlagUnrecognized,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_primitive_non_escape() {
+ assert_eq!(
+ parser(r".").parse_primitive(),
+ Ok(Primitive::Dot(span(0..1)))
+ );
+ assert_eq!(
+ parser(r"^").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..1),
+ kind: ast::AssertionKind::StartLine,
+ }))
+ );
+ assert_eq!(
+ parser(r"$").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..1),
+ kind: ast::AssertionKind::EndLine,
+ }))
+ );
+
+ assert_eq!(
+ parser(r"a").parse_primitive(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..1),
+ kind: ast::LiteralKind::Verbatim,
+ c: 'a',
+ }))
+ );
+ assert_eq!(
+ parser(r"|").parse_primitive(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..1),
+ kind: ast::LiteralKind::Verbatim,
+ c: '|',
+ }))
+ );
+ assert_eq!(
+ parser(r"☃").parse_primitive(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span_range("☃", 0..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: '☃',
+ }))
+ );
+ }
+
+ #[test]
+ fn parse_escape() {
+ assert_eq!(
+ parser(r"\|").parse_primitive(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..2),
+ kind: ast::LiteralKind::Punctuation,
+ c: '|',
+ }))
+ );
+ let specials = &[
+ (r"\a", '\x07', ast::SpecialLiteralKind::Bell),
+ (r"\f", '\x0C', ast::SpecialLiteralKind::FormFeed),
+ (r"\t", '\t', ast::SpecialLiteralKind::Tab),
+ (r"\n", '\n', ast::SpecialLiteralKind::LineFeed),
+ (r"\r", '\r', ast::SpecialLiteralKind::CarriageReturn),
+ (r"\v", '\x0B', ast::SpecialLiteralKind::VerticalTab),
+ ];
+ for &(pat, c, ref kind) in specials {
+ assert_eq!(
+ parser(pat).parse_primitive(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..2),
+ kind: ast::LiteralKind::Special(kind.clone()),
+ c,
+ }))
+ );
+ }
+ assert_eq!(
+ parser(r"\A").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..2),
+ kind: ast::AssertionKind::StartText,
+ }))
+ );
+ assert_eq!(
+ parser(r"\z").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..2),
+ kind: ast::AssertionKind::EndText,
+ }))
+ );
+ assert_eq!(
+ parser(r"\b").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..2),
+ kind: ast::AssertionKind::WordBoundary,
+ }))
+ );
+ assert_eq!(
+ parser(r"\B").parse_primitive(),
+ Ok(Primitive::Assertion(ast::Assertion {
+ span: span(0..2),
+ kind: ast::AssertionKind::NotWordBoundary,
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\").parse_escape().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\y").parse_escape().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::EscapeUnrecognized,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_unsupported_backreference() {
+ assert_eq!(
+ parser(r"\0").parse_escape().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::UnsupportedBackreference,
+ }
+ );
+ assert_eq!(
+ parser(r"\9").parse_escape().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::UnsupportedBackreference,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_octal() {
+ for i in 0..511 {
+ let pat = format!(r"\{:o}", i);
+ assert_eq!(
+ parser_octal(&pat).parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..pat.len()),
+ kind: ast::LiteralKind::Octal,
+ c: ::std::char::from_u32(i).unwrap(),
+ }))
+ );
+ }
+ assert_eq!(
+ parser_octal(r"\778").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..3),
+ kind: ast::LiteralKind::Octal,
+ c: '?',
+ }))
+ );
+ assert_eq!(
+ parser_octal(r"\7777").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..4),
+ kind: ast::LiteralKind::Octal,
+ c: '\u{01FF}',
+ }))
+ );
+ assert_eq!(
+ parser_octal(r"\778").parse(),
+ Ok(Ast::Concat(ast::Concat {
+ span: span(0..4),
+ asts: vec![
+ Ast::Literal(ast::Literal {
+ span: span(0..3),
+ kind: ast::LiteralKind::Octal,
+ c: '?',
+ }),
+ Ast::Literal(ast::Literal {
+ span: span(3..4),
+ kind: ast::LiteralKind::Verbatim,
+ c: '8',
+ }),
+ ],
+ }))
+ );
+ assert_eq!(
+ parser_octal(r"\7777").parse(),
+ Ok(Ast::Concat(ast::Concat {
+ span: span(0..5),
+ asts: vec![
+ Ast::Literal(ast::Literal {
+ span: span(0..4),
+ kind: ast::LiteralKind::Octal,
+ c: '\u{01FF}',
+ }),
+ Ast::Literal(ast::Literal {
+ span: span(4..5),
+ kind: ast::LiteralKind::Verbatim,
+ c: '7',
+ }),
+ ],
+ }))
+ );
+
+ assert_eq!(
+ parser_octal(r"\8").parse_escape().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::EscapeUnrecognized,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_hex_two() {
+ for i in 0..256 {
+ let pat = format!(r"\x{:02x}", i);
+ assert_eq!(
+ parser(&pat).parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..pat.len()),
+ kind: ast::LiteralKind::HexFixed(ast::HexLiteralKind::X),
+ c: ::std::char::from_u32(i).unwrap(),
+ }))
+ );
+ }
+
+ assert_eq!(
+ parser(r"\xF").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\xG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\xFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_hex_four() {
+ for i in 0..65536 {
+ let c = match ::std::char::from_u32(i) {
+ None => continue,
+ Some(c) => c,
+ };
+ let pat = format!(r"\u{:04x}", i);
+ assert_eq!(
+ parser(&pat).parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..pat.len()),
+ kind: ast::LiteralKind::HexFixed(
+ ast::HexLiteralKind::UnicodeShort
+ ),
+ c,
+ }))
+ );
+ }
+
+ assert_eq!(
+ parser(r"\uF").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\uG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\uFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\uFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\uFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(5..6),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\uD800").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..6),
+ kind: ast::ErrorKind::EscapeHexInvalid,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_hex_eight() {
+ for i in 0..65536 {
+ let c = match ::std::char::from_u32(i) {
+ None => continue,
+ Some(c) => c,
+ };
+ let pat = format!(r"\U{:08x}", i);
+ assert_eq!(
+ parser(&pat).parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..pat.len()),
+ kind: ast::LiteralKind::HexFixed(
+ ast::HexLiteralKind::UnicodeLong
+ ),
+ c,
+ }))
+ );
+ }
+
+ assert_eq!(
+ parser(r"\UF").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\UG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..4),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(5..6),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(6..7),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(7..8),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFFFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(8..9),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\UFFFFFFFG").parse_escape().unwrap_err(),
+ TestError {
+ span: span(9..10),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_hex_brace() {
+ assert_eq!(
+ parser(r"\u{26c4}").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..8),
+ kind: ast::LiteralKind::HexBrace(
+ ast::HexLiteralKind::UnicodeShort
+ ),
+ c: '⛄',
+ }))
+ );
+ assert_eq!(
+ parser(r"\U{26c4}").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..8),
+ kind: ast::LiteralKind::HexBrace(
+ ast::HexLiteralKind::UnicodeLong
+ ),
+ c: '⛄',
+ }))
+ );
+ assert_eq!(
+ parser(r"\x{26c4}").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..8),
+ kind: ast::LiteralKind::HexBrace(ast::HexLiteralKind::X),
+ c: '⛄',
+ }))
+ );
+ assert_eq!(
+ parser(r"\x{26C4}").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..8),
+ kind: ast::LiteralKind::HexBrace(ast::HexLiteralKind::X),
+ c: '⛄',
+ }))
+ );
+ assert_eq!(
+ parser(r"\x{10fFfF}").parse_escape(),
+ Ok(Primitive::Literal(ast::Literal {
+ span: span(0..10),
+ kind: ast::LiteralKind::HexBrace(ast::HexLiteralKind::X),
+ c: '\u{10FFFF}',
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\x").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..2),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{FF").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..5),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{}").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..4),
+ kind: ast::ErrorKind::EscapeHexEmpty,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{FGF}").parse_escape().unwrap_err(),
+ TestError {
+ span: span(4..5),
+ kind: ast::ErrorKind::EscapeHexInvalidDigit,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{FFFFFF}").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..9),
+ kind: ast::ErrorKind::EscapeHexInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{D800}").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..7),
+ kind: ast::ErrorKind::EscapeHexInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"\x{FFFFFFFFF}").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..12),
+ kind: ast::ErrorKind::EscapeHexInvalid,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_decimal() {
+ assert_eq!(parser("123").parse_decimal(), Ok(123));
+ assert_eq!(parser("0").parse_decimal(), Ok(0));
+ assert_eq!(parser("01").parse_decimal(), Ok(1));
+
+ assert_eq!(
+ parser("-1").parse_decimal().unwrap_err(),
+ TestError { span: span(0..0), kind: ast::ErrorKind::DecimalEmpty }
+ );
+ assert_eq!(
+ parser("").parse_decimal().unwrap_err(),
+ TestError { span: span(0..0), kind: ast::ErrorKind::DecimalEmpty }
+ );
+ assert_eq!(
+ parser("9999999999").parse_decimal().unwrap_err(),
+ TestError {
+ span: span(0..10),
+ kind: ast::ErrorKind::DecimalInvalid,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_set_class() {
+ fn union(span: Span, items: Vec<ast::ClassSetItem>) -> ast::ClassSet {
+ ast::ClassSet::union(ast::ClassSetUnion { span, items })
+ }
+
+ fn intersection(
+ span: Span,
+ lhs: ast::ClassSet,
+ rhs: ast::ClassSet,
+ ) -> ast::ClassSet {
+ ast::ClassSet::BinaryOp(ast::ClassSetBinaryOp {
+ span,
+ kind: ast::ClassSetBinaryOpKind::Intersection,
+ lhs: Box::new(lhs),
+ rhs: Box::new(rhs),
+ })
+ }
+
+ fn difference(
+ span: Span,
+ lhs: ast::ClassSet,
+ rhs: ast::ClassSet,
+ ) -> ast::ClassSet {
+ ast::ClassSet::BinaryOp(ast::ClassSetBinaryOp {
+ span,
+ kind: ast::ClassSetBinaryOpKind::Difference,
+ lhs: Box::new(lhs),
+ rhs: Box::new(rhs),
+ })
+ }
+
+ fn symdifference(
+ span: Span,
+ lhs: ast::ClassSet,
+ rhs: ast::ClassSet,
+ ) -> ast::ClassSet {
+ ast::ClassSet::BinaryOp(ast::ClassSetBinaryOp {
+ span,
+ kind: ast::ClassSetBinaryOpKind::SymmetricDifference,
+ lhs: Box::new(lhs),
+ rhs: Box::new(rhs),
+ })
+ }
+
+ fn itemset(item: ast::ClassSetItem) -> ast::ClassSet {
+ ast::ClassSet::Item(item)
+ }
+
+ fn item_ascii(cls: ast::ClassAscii) -> ast::ClassSetItem {
+ ast::ClassSetItem::Ascii(cls)
+ }
+
+ fn item_unicode(cls: ast::ClassUnicode) -> ast::ClassSetItem {
+ ast::ClassSetItem::Unicode(cls)
+ }
+
+ fn item_perl(cls: ast::ClassPerl) -> ast::ClassSetItem {
+ ast::ClassSetItem::Perl(cls)
+ }
+
+ fn item_bracket(cls: ast::ClassBracketed) -> ast::ClassSetItem {
+ ast::ClassSetItem::Bracketed(Box::new(cls))
+ }
+
+ fn lit(span: Span, c: char) -> ast::ClassSetItem {
+ ast::ClassSetItem::Literal(ast::Literal {
+ span,
+ kind: ast::LiteralKind::Verbatim,
+ c,
+ })
+ }
+
+ fn empty(span: Span) -> ast::ClassSetItem {
+ ast::ClassSetItem::Empty(span)
+ }
+
+ fn range(span: Span, start: char, end: char) -> ast::ClassSetItem {
+ let pos1 = Position {
+ offset: span.start.offset + start.len_utf8(),
+ column: span.start.column + 1,
+ ..span.start
+ };
+ let pos2 = Position {
+ offset: span.end.offset - end.len_utf8(),
+ column: span.end.column - 1,
+ ..span.end
+ };
+ ast::ClassSetItem::Range(ast::ClassSetRange {
+ span,
+ start: ast::Literal {
+ span: Span { end: pos1, ..span },
+ kind: ast::LiteralKind::Verbatim,
+ c: start,
+ },
+ end: ast::Literal {
+ span: Span { start: pos2, ..span },
+ kind: ast::LiteralKind::Verbatim,
+ c: end,
+ },
+ })
+ }
+
+ fn alnum(span: Span, negated: bool) -> ast::ClassAscii {
+ ast::ClassAscii { span, kind: ast::ClassAsciiKind::Alnum, negated }
+ }
+
+ fn lower(span: Span, negated: bool) -> ast::ClassAscii {
+ ast::ClassAscii { span, kind: ast::ClassAsciiKind::Lower, negated }
+ }
+
+ assert_eq!(
+ parser("[[:alnum:]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..11),
+ negated: false,
+ kind: itemset(item_ascii(alnum(span(1..10), false))),
+ })))
+ );
+ assert_eq!(
+ parser("[[[:alnum:]]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..13),
+ negated: false,
+ kind: itemset(item_bracket(ast::ClassBracketed {
+ span: span(1..12),
+ negated: false,
+ kind: itemset(item_ascii(alnum(span(2..11), false))),
+ })),
+ })))
+ );
+ assert_eq!(
+ parser("[[:alnum:]&&[:lower:]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..22),
+ negated: false,
+ kind: intersection(
+ span(1..21),
+ itemset(item_ascii(alnum(span(1..10), false))),
+ itemset(item_ascii(lower(span(12..21), false))),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser("[[:alnum:]--[:lower:]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..22),
+ negated: false,
+ kind: difference(
+ span(1..21),
+ itemset(item_ascii(alnum(span(1..10), false))),
+ itemset(item_ascii(lower(span(12..21), false))),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser("[[:alnum:]~~[:lower:]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..22),
+ negated: false,
+ kind: symdifference(
+ span(1..21),
+ itemset(item_ascii(alnum(span(1..10), false))),
+ itemset(item_ascii(lower(span(12..21), false))),
+ ),
+ })))
+ );
+
+ assert_eq!(
+ parser("[a]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..3),
+ negated: false,
+ kind: itemset(lit(span(1..2), 'a')),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a\]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..5),
+ negated: false,
+ kind: union(
+ span(1..4),
+ vec![
+ lit(span(1..2), 'a'),
+ ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..4),
+ kind: ast::LiteralKind::Punctuation,
+ c: ']',
+ }),
+ ]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a\-z]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..6),
+ negated: false,
+ kind: union(
+ span(1..5),
+ vec![
+ lit(span(1..2), 'a'),
+ ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..4),
+ kind: ast::LiteralKind::Punctuation,
+ c: '-',
+ }),
+ lit(span(4..5), 'z'),
+ ]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser("[ab]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: union(
+ span(1..3),
+ vec![lit(span(1..2), 'a'), lit(span(2..3), 'b'),]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser("[a-]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: union(
+ span(1..3),
+ vec![lit(span(1..2), 'a'), lit(span(2..3), '-'),]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser("[-a]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: union(
+ span(1..3),
+ vec![lit(span(1..2), '-'), lit(span(2..3), 'a'),]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\pL]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..5),
+ negated: false,
+ kind: itemset(item_unicode(ast::ClassUnicode {
+ span: span(1..4),
+ negated: false,
+ kind: ast::ClassUnicodeKind::OneLetter('L'),
+ })),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\w]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: itemset(item_perl(ast::ClassPerl {
+ span: span(1..3),
+ kind: ast::ClassPerlKind::Word,
+ negated: false,
+ })),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a\wz]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..6),
+ negated: false,
+ kind: union(
+ span(1..5),
+ vec![
+ lit(span(1..2), 'a'),
+ item_perl(ast::ClassPerl {
+ span: span(2..4),
+ kind: ast::ClassPerlKind::Word,
+ negated: false,
+ }),
+ lit(span(4..5), 'z'),
+ ]
+ ),
+ })))
+ );
+
+ assert_eq!(
+ parser("[a-z]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..5),
+ negated: false,
+ kind: itemset(range(span(1..4), 'a', 'z')),
+ })))
+ );
+ assert_eq!(
+ parser("[a-cx-z]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..8),
+ negated: false,
+ kind: union(
+ span(1..7),
+ vec![
+ range(span(1..4), 'a', 'c'),
+ range(span(4..7), 'x', 'z'),
+ ]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\w&&a-cx-z]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..12),
+ negated: false,
+ kind: intersection(
+ span(1..11),
+ itemset(item_perl(ast::ClassPerl {
+ span: span(1..3),
+ kind: ast::ClassPerlKind::Word,
+ negated: false,
+ })),
+ union(
+ span(5..11),
+ vec![
+ range(span(5..8), 'a', 'c'),
+ range(span(8..11), 'x', 'z'),
+ ]
+ ),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a-cx-z&&\w]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..12),
+ negated: false,
+ kind: intersection(
+ span(1..11),
+ union(
+ span(1..7),
+ vec![
+ range(span(1..4), 'a', 'c'),
+ range(span(4..7), 'x', 'z'),
+ ]
+ ),
+ itemset(item_perl(ast::ClassPerl {
+ span: span(9..11),
+ kind: ast::ClassPerlKind::Word,
+ negated: false,
+ })),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a--b--c]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..9),
+ negated: false,
+ kind: difference(
+ span(1..8),
+ difference(
+ span(1..5),
+ itemset(lit(span(1..2), 'a')),
+ itemset(lit(span(4..5), 'b')),
+ ),
+ itemset(lit(span(7..8), 'c')),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[a~~b~~c]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..9),
+ negated: false,
+ kind: symdifference(
+ span(1..8),
+ symdifference(
+ span(1..5),
+ itemset(lit(span(1..2), 'a')),
+ itemset(lit(span(4..5), 'b')),
+ ),
+ itemset(lit(span(7..8), 'c')),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\^&&^]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..7),
+ negated: false,
+ kind: intersection(
+ span(1..6),
+ itemset(ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..3),
+ kind: ast::LiteralKind::Punctuation,
+ c: '^',
+ })),
+ itemset(lit(span(5..6), '^')),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\&&&&]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..7),
+ negated: false,
+ kind: intersection(
+ span(1..6),
+ itemset(ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..3),
+ kind: ast::LiteralKind::Punctuation,
+ c: '&',
+ })),
+ itemset(lit(span(5..6), '&')),
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[&&&&]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..6),
+ negated: false,
+ kind: intersection(
+ span(1..5),
+ intersection(
+ span(1..3),
+ itemset(empty(span(1..1))),
+ itemset(empty(span(3..3))),
+ ),
+ itemset(empty(span(5..5))),
+ ),
+ })))
+ );
+
+ let pat = "[☃-⛄]";
+ assert_eq!(
+ parser(pat).parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span_range(pat, 0..9),
+ negated: false,
+ kind: itemset(ast::ClassSetItem::Range(ast::ClassSetRange {
+ span: span_range(pat, 1..8),
+ start: ast::Literal {
+ span: span_range(pat, 1..4),
+ kind: ast::LiteralKind::Verbatim,
+ c: '☃',
+ },
+ end: ast::Literal {
+ span: span_range(pat, 5..8),
+ kind: ast::LiteralKind::Verbatim,
+ c: '⛄',
+ },
+ })),
+ })))
+ );
+
+ assert_eq!(
+ parser(r"[]]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..3),
+ negated: false,
+ kind: itemset(lit(span(1..2), ']')),
+ })))
+ );
+ assert_eq!(
+ parser(r"[]\[]").parse(),
+ Ok(Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..5),
+ negated: false,
+ kind: union(
+ span(1..4),
+ vec![
+ lit(span(1..2), ']'),
+ ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..4),
+ kind: ast::LiteralKind::Punctuation,
+ c: '[',
+ }),
+ ]
+ ),
+ })))
+ );
+ assert_eq!(
+ parser(r"[\[]]").parse(),
+ Ok(concat(
+ 0..5,
+ vec![
+ Ast::Class(ast::Class::Bracketed(ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: itemset(ast::ClassSetItem::Literal(
+ ast::Literal {
+ span: span(1..3),
+ kind: ast::LiteralKind::Punctuation,
+ c: '[',
+ }
+ )),
+ })),
+ Ast::Literal(ast::Literal {
+ span: span(4..5),
+ kind: ast::LiteralKind::Verbatim,
+ c: ']',
+ }),
+ ]
+ ))
+ );
+
+ assert_eq!(
+ parser("[").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[[").parse().unwrap_err(),
+ TestError {
+ span: span(1..2),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[[-]").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[[[:alnum:]").parse().unwrap_err(),
+ TestError {
+ span: span(1..2),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser(r"[\b]").parse().unwrap_err(),
+ TestError {
+ span: span(1..3),
+ kind: ast::ErrorKind::ClassEscapeInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"[\w-a]").parse().unwrap_err(),
+ TestError {
+ span: span(1..3),
+ kind: ast::ErrorKind::ClassRangeLiteral,
+ }
+ );
+ assert_eq!(
+ parser(r"[a-\w]").parse().unwrap_err(),
+ TestError {
+ span: span(3..5),
+ kind: ast::ErrorKind::ClassRangeLiteral,
+ }
+ );
+ assert_eq!(
+ parser(r"[z-a]").parse().unwrap_err(),
+ TestError {
+ span: span(1..4),
+ kind: ast::ErrorKind::ClassRangeInvalid,
+ }
+ );
+
+ assert_eq!(
+ parser_ignore_whitespace("[a ").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser_ignore_whitespace("[a- ").parse().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_set_class_open() {
+ assert_eq!(parser("[a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..1),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(1..1),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion { span: span(1..1), items: vec![] };
+ Ok((set, union))
+ });
+ assert_eq!(
+ parser_ignore_whitespace("[ a]").parse_set_class_open(),
+ {
+ let set = ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(4..4),
+ items: vec![],
+ }),
+ };
+ let union =
+ ast::ClassSetUnion { span: span(4..4), items: vec![] };
+ Ok((set, union))
+ }
+ );
+ assert_eq!(parser("[^a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..2),
+ negated: true,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(2..2),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion { span: span(2..2), items: vec![] };
+ Ok((set, union))
+ });
+ assert_eq!(
+ parser_ignore_whitespace("[ ^ a]").parse_set_class_open(),
+ {
+ let set = ast::ClassBracketed {
+ span: span(0..4),
+ negated: true,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(4..4),
+ items: vec![],
+ }),
+ };
+ let union =
+ ast::ClassSetUnion { span: span(4..4), items: vec![] };
+ Ok((set, union))
+ }
+ );
+ assert_eq!(parser("[-a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..2),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(1..1),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(1..2),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..2),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ })],
+ };
+ Ok((set, union))
+ });
+ assert_eq!(
+ parser_ignore_whitespace("[ - a]").parse_set_class_open(),
+ {
+ let set = ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(2..2),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(2..3),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ })],
+ };
+ Ok((set, union))
+ }
+ );
+ assert_eq!(parser("[^-a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..3),
+ negated: true,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(2..2),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(2..3),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ })],
+ };
+ Ok((set, union))
+ });
+ assert_eq!(parser("[--a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..3),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(1..1),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(1..3),
+ items: vec![
+ ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..2),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ }),
+ ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ }),
+ ],
+ };
+ Ok((set, union))
+ });
+ assert_eq!(parser("[]a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..2),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(1..1),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(1..2),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..2),
+ kind: ast::LiteralKind::Verbatim,
+ c: ']',
+ })],
+ };
+ Ok((set, union))
+ });
+ assert_eq!(
+ parser_ignore_whitespace("[ ] a]").parse_set_class_open(),
+ {
+ let set = ast::ClassBracketed {
+ span: span(0..4),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(2..2),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(2..3),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: ']',
+ })],
+ };
+ Ok((set, union))
+ }
+ );
+ assert_eq!(parser("[^]a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..3),
+ negated: true,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(2..2),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(2..3),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: ']',
+ })],
+ };
+ Ok((set, union))
+ });
+ assert_eq!(parser("[-]a]").parse_set_class_open(), {
+ let set = ast::ClassBracketed {
+ span: span(0..2),
+ negated: false,
+ kind: ast::ClassSet::union(ast::ClassSetUnion {
+ span: span(1..1),
+ items: vec![],
+ }),
+ };
+ let union = ast::ClassSetUnion {
+ span: span(1..2),
+ items: vec![ast::ClassSetItem::Literal(ast::Literal {
+ span: span(1..2),
+ kind: ast::LiteralKind::Verbatim,
+ c: '-',
+ })],
+ };
+ Ok((set, union))
+ });
+
+ assert_eq!(
+ parser("[").parse_set_class_open().unwrap_err(),
+ TestError {
+ span: span(0..1),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser_ignore_whitespace("[ ")
+ .parse_set_class_open()
+ .unwrap_err(),
+ TestError {
+ span: span(0..5),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[^").parse_set_class_open().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[]").parse_set_class_open().unwrap_err(),
+ TestError {
+ span: span(0..2),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[-").parse_set_class_open().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ assert_eq!(
+ parser("[--").parse_set_class_open().unwrap_err(),
+ TestError {
+ span: span(0..0),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+
+ // See: https://github.com/rust-lang/regex/issues/792
+ assert_eq!(
+ parser("(?x)[-#]").parse_with_comments().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::ClassUnclosed,
+ }
+ );
+ }
+
+ #[test]
+ fn maybe_parse_ascii_class() {
+ assert_eq!(
+ parser(r"[:alnum:]").maybe_parse_ascii_class(),
+ Some(ast::ClassAscii {
+ span: span(0..9),
+ kind: ast::ClassAsciiKind::Alnum,
+ negated: false,
+ })
+ );
+ assert_eq!(
+ parser(r"[:alnum:]A").maybe_parse_ascii_class(),
+ Some(ast::ClassAscii {
+ span: span(0..9),
+ kind: ast::ClassAsciiKind::Alnum,
+ negated: false,
+ })
+ );
+ assert_eq!(
+ parser(r"[:^alnum:]").maybe_parse_ascii_class(),
+ Some(ast::ClassAscii {
+ span: span(0..10),
+ kind: ast::ClassAsciiKind::Alnum,
+ negated: true,
+ })
+ );
+
+ let p = parser(r"[:");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+
+ let p = parser(r"[:^");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+
+ let p = parser(r"[^:alnum:]");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+
+ let p = parser(r"[:alnnum:]");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+
+ let p = parser(r"[:alnum]");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+
+ let p = parser(r"[:alnum:");
+ assert_eq!(p.maybe_parse_ascii_class(), None);
+ assert_eq!(p.offset(), 0);
+ }
+
+ #[test]
+ fn parse_unicode_class() {
+ assert_eq!(
+ parser(r"\pN").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..3),
+ negated: false,
+ kind: ast::ClassUnicodeKind::OneLetter('N'),
+ }))
+ );
+ assert_eq!(
+ parser(r"\PN").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..3),
+ negated: true,
+ kind: ast::ClassUnicodeKind::OneLetter('N'),
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{N}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..5),
+ negated: false,
+ kind: ast::ClassUnicodeKind::Named(s("N")),
+ }))
+ );
+ assert_eq!(
+ parser(r"\P{N}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..5),
+ negated: true,
+ kind: ast::ClassUnicodeKind::Named(s("N")),
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{Greek}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..9),
+ negated: false,
+ kind: ast::ClassUnicodeKind::Named(s("Greek")),
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\p{scx:Katakana}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..16),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Colon,
+ name: s("scx"),
+ value: s("Katakana"),
+ },
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{scx=Katakana}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..16),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Equal,
+ name: s("scx"),
+ value: s("Katakana"),
+ },
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{scx!=Katakana}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..17),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::NotEqual,
+ name: s("scx"),
+ value: s("Katakana"),
+ },
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\p{:}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..5),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Colon,
+ name: s(""),
+ value: s(""),
+ },
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{=}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..5),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::Equal,
+ name: s(""),
+ value: s(""),
+ },
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{!=}").parse_escape(),
+ Ok(Primitive::Unicode(ast::ClassUnicode {
+ span: span(0..6),
+ negated: false,
+ kind: ast::ClassUnicodeKind::NamedValue {
+ op: ast::ClassUnicodeOpKind::NotEqual,
+ name: s(""),
+ value: s(""),
+ },
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\p").parse_escape().unwrap_err(),
+ TestError {
+ span: span(2..2),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\p{").parse_escape().unwrap_err(),
+ TestError {
+ span: span(3..3),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\p{N").parse_escape().unwrap_err(),
+ TestError {
+ span: span(4..4),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+ assert_eq!(
+ parser(r"\p{Greek").parse_escape().unwrap_err(),
+ TestError {
+ span: span(8..8),
+ kind: ast::ErrorKind::EscapeUnexpectedEof,
+ }
+ );
+
+ assert_eq!(
+ parser(r"\pNz").parse(),
+ Ok(Ast::Concat(ast::Concat {
+ span: span(0..4),
+ asts: vec![
+ Ast::Class(ast::Class::Unicode(ast::ClassUnicode {
+ span: span(0..3),
+ negated: false,
+ kind: ast::ClassUnicodeKind::OneLetter('N'),
+ })),
+ Ast::Literal(ast::Literal {
+ span: span(3..4),
+ kind: ast::LiteralKind::Verbatim,
+ c: 'z',
+ }),
+ ],
+ }))
+ );
+ assert_eq!(
+ parser(r"\p{Greek}z").parse(),
+ Ok(Ast::Concat(ast::Concat {
+ span: span(0..10),
+ asts: vec![
+ Ast::Class(ast::Class::Unicode(ast::ClassUnicode {
+ span: span(0..9),
+ negated: false,
+ kind: ast::ClassUnicodeKind::Named(s("Greek")),
+ })),
+ Ast::Literal(ast::Literal {
+ span: span(9..10),
+ kind: ast::LiteralKind::Verbatim,
+ c: 'z',
+ }),
+ ],
+ }))
+ );
+ assert_eq!(
+ parser(r"\p\{").parse().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::UnicodeClassInvalid,
+ }
+ );
+ assert_eq!(
+ parser(r"\P\{").parse().unwrap_err(),
+ TestError {
+ span: span(2..3),
+ kind: ast::ErrorKind::UnicodeClassInvalid,
+ }
+ );
+ }
+
+ #[test]
+ fn parse_perl_class() {
+ assert_eq!(
+ parser(r"\d").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Digit,
+ negated: false,
+ }))
+ );
+ assert_eq!(
+ parser(r"\D").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Digit,
+ negated: true,
+ }))
+ );
+ assert_eq!(
+ parser(r"\s").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Space,
+ negated: false,
+ }))
+ );
+ assert_eq!(
+ parser(r"\S").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Space,
+ negated: true,
+ }))
+ );
+ assert_eq!(
+ parser(r"\w").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Word,
+ negated: false,
+ }))
+ );
+ assert_eq!(
+ parser(r"\W").parse_escape(),
+ Ok(Primitive::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Word,
+ negated: true,
+ }))
+ );
+
+ assert_eq!(
+ parser(r"\d").parse(),
+ Ok(Ast::Class(ast::Class::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Digit,
+ negated: false,
+ })))
+ );
+ assert_eq!(
+ parser(r"\dz").parse(),
+ Ok(Ast::Concat(ast::Concat {
+ span: span(0..3),
+ asts: vec![
+ Ast::Class(ast::Class::Perl(ast::ClassPerl {
+ span: span(0..2),
+ kind: ast::ClassPerlKind::Digit,
+ negated: false,
+ })),
+ Ast::Literal(ast::Literal {
+ span: span(2..3),
+ kind: ast::LiteralKind::Verbatim,
+ c: 'z',
+ }),
+ ],
+ }))
+ );
+ }
+
+ // This tests a bug fix where the nest limit checker wasn't decrementing
+ // its depth during post-traversal, which causes long regexes to trip
+ // the default limit too aggressively.
+ #[test]
+ fn regression_454_nest_too_big() {
+ let pattern = r#"
+ 2(?:
+ [45]\d{3}|
+ 7(?:
+ 1[0-267]|
+ 2[0-289]|
+ 3[0-29]|
+ 4[01]|
+ 5[1-3]|
+ 6[013]|
+ 7[0178]|
+ 91
+ )|
+ 8(?:
+ 0[125]|
+ [139][1-6]|
+ 2[0157-9]|
+ 41|
+ 6[1-35]|
+ 7[1-5]|
+ 8[1-8]|
+ 90
+ )|
+ 9(?:
+ 0[0-2]|
+ 1[0-4]|
+ 2[568]|
+ 3[3-6]|
+ 5[5-7]|
+ 6[0167]|
+ 7[15]|
+ 8[0146-9]
+ )
+ )\d{4}
+ "#;
+ assert!(parser_nest_limit(pattern, 50).parse().is_ok());
+ }
+
+ // This tests that we treat a trailing `-` in a character class as a
+ // literal `-` even when whitespace mode is enabled and there is whitespace
+ // after the trailing `-`.
+ #[test]
+ fn regression_455_trailing_dash_ignore_whitespace() {
+ assert!(parser("(?x)[ / - ]").parse().is_ok());
+ assert!(parser("(?x)[ a - ]").parse().is_ok());
+ assert!(parser(
+ "(?x)[
+ a
+ - ]
+ "
+ )
+ .parse()
+ .is_ok());
+ assert!(parser(
+ "(?x)[
+ a # wat
+ - ]
+ "
+ )
+ .parse()
+ .is_ok());
+
+ assert!(parser("(?x)[ / -").parse().is_err());
+ assert!(parser("(?x)[ / - ").parse().is_err());
+ assert!(parser(
+ "(?x)[
+ / -
+ "
+ )
+ .parse()
+ .is_err());
+ assert!(parser(
+ "(?x)[
+ / - # wat
+ "
+ )
+ .parse()
+ .is_err());
+ }
+}