Import 'regex' package vesion 1.3.6
* Add OWNERS
* No Android.bp yet
Bug: 152884384
Test: make
Change-Id: I455caf7833b6c437c1c133bc7b2f47b83da9cbce
diff --git a/src/re_builder.rs b/src/re_builder.rs
new file mode 100644
index 0000000..3fef99d
--- /dev/null
+++ b/src/re_builder.rs
@@ -0,0 +1,419 @@
+/// The set of user configurable options for compiling zero or more regexes.
+#[derive(Clone, Debug)]
+#[allow(missing_docs)]
+pub struct RegexOptions {
+ pub pats: Vec<String>,
+ pub size_limit: usize,
+ pub dfa_size_limit: usize,
+ pub nest_limit: u32,
+ pub case_insensitive: bool,
+ pub multi_line: bool,
+ pub dot_matches_new_line: bool,
+ pub swap_greed: bool,
+ pub ignore_whitespace: bool,
+ pub unicode: bool,
+ pub octal: bool,
+}
+
+impl Default for RegexOptions {
+ fn default() -> Self {
+ RegexOptions {
+ pats: vec![],
+ size_limit: 10 * (1 << 20),
+ dfa_size_limit: 2 * (1 << 20),
+ nest_limit: 250,
+ case_insensitive: false,
+ multi_line: false,
+ dot_matches_new_line: false,
+ swap_greed: false,
+ ignore_whitespace: false,
+ unicode: true,
+ octal: false,
+ }
+ }
+}
+
+macro_rules! define_builder {
+ ($name:ident, $regex_mod:ident, $only_utf8:expr) => {
+ pub mod $name {
+ use super::RegexOptions;
+ use error::Error;
+ use exec::ExecBuilder;
+
+ use $regex_mod::Regex;
+
+ /// A configurable builder for a regular expression.
+ ///
+ /// A builder can be used to configure how the regex is built, for example, by
+ /// setting the default flags (which can be overridden in the expression
+ /// itself) or setting various limits.
+ pub struct RegexBuilder(RegexOptions);
+
+ impl RegexBuilder {
+ /// Create a new regular expression builder with the given pattern.
+ ///
+ /// If the pattern is invalid, then an error will be returned when
+ /// `build` is called.
+ pub fn new(pattern: &str) -> RegexBuilder {
+ let mut builder = RegexBuilder(RegexOptions::default());
+ builder.0.pats.push(pattern.to_owned());
+ builder
+ }
+
+ /// Consume the builder and compile the regular expression.
+ ///
+ /// Note that calling `as_str` on the resulting `Regex` will produce the
+ /// pattern given to `new` verbatim. Notably, it will not incorporate any
+ /// of the flags set on this builder.
+ pub fn build(&self) -> Result<Regex, Error> {
+ ExecBuilder::new_options(self.0.clone())
+ .only_utf8($only_utf8)
+ .build()
+ .map(Regex::from)
+ }
+
+ /// Set the value for the case insensitive (`i`) flag.
+ ///
+ /// When enabled, letters in the pattern will match both upper case and
+ /// lower case variants.
+ pub fn case_insensitive(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexBuilder {
+ self.0.case_insensitive = yes;
+ self
+ }
+
+ /// Set the value for the multi-line matching (`m`) flag.
+ ///
+ /// When enabled, `^` matches the beginning of lines and `$` matches the
+ /// end of lines.
+ ///
+ /// By default, they match beginning/end of the input.
+ pub fn multi_line(&mut self, yes: bool) -> &mut RegexBuilder {
+ self.0.multi_line = yes;
+ self
+ }
+
+ /// Set the value for the any character (`s`) flag, where in `.` matches
+ /// anything when `s` is set and matches anything except for new line when
+ /// it is not set (the default).
+ ///
+ /// N.B. "matches anything" means "any byte" when Unicode is disabled and
+ /// means "any valid UTF-8 encoding of any Unicode scalar value" when
+ /// Unicode is enabled.
+ pub fn dot_matches_new_line(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexBuilder {
+ self.0.dot_matches_new_line = yes;
+ self
+ }
+
+ /// Set the value for the greedy swap (`U`) flag.
+ ///
+ /// When enabled, a pattern like `a*` is lazy (tries to find shortest
+ /// match) and `a*?` is greedy (tries to find longest match).
+ ///
+ /// By default, `a*` is greedy and `a*?` is lazy.
+ pub fn swap_greed(&mut self, yes: bool) -> &mut RegexBuilder {
+ self.0.swap_greed = yes;
+ self
+ }
+
+ /// Set the value for the ignore whitespace (`x`) flag.
+ ///
+ /// When enabled, whitespace such as new lines and spaces will be ignored
+ /// between expressions of the pattern, and `#` can be used to start a
+ /// comment until the next new line.
+ pub fn ignore_whitespace(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexBuilder {
+ self.0.ignore_whitespace = yes;
+ self
+ }
+
+ /// Set the value for the Unicode (`u`) flag.
+ ///
+ /// Enabled by default. When disabled, character classes such as `\w` only
+ /// match ASCII word characters instead of all Unicode word characters.
+ pub fn unicode(&mut self, yes: bool) -> &mut RegexBuilder {
+ self.0.unicode = yes;
+ 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 RegexBuilder {
+ self.0.octal = yes;
+ self
+ }
+
+ /// Set the approximate size limit of the compiled regular expression.
+ ///
+ /// This roughly corresponds to the number of bytes occupied by a single
+ /// compiled program. If the program exceeds this number, then a
+ /// compilation error is returned.
+ pub fn size_limit(
+ &mut self,
+ limit: usize,
+ ) -> &mut RegexBuilder {
+ self.0.size_limit = limit;
+ self
+ }
+
+ /// Set the approximate size of the cache used by the DFA.
+ ///
+ /// This roughly corresponds to the number of bytes that the DFA will
+ /// use while searching.
+ ///
+ /// Note that this is a *per thread* limit. There is no way to set a global
+ /// limit. In particular, if a regex is used from multiple threads
+ /// simultaneously, then each thread may use up to the number of bytes
+ /// specified here.
+ pub fn dfa_size_limit(
+ &mut self,
+ limit: usize,
+ ) -> &mut RegexBuilder {
+ self.0.dfa_size_limit = limit;
+ self
+ }
+
+ /// 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 RegexBuilder {
+ self.0.nest_limit = limit;
+ self
+ }
+ }
+ }
+ };
+}
+
+define_builder!(bytes, re_bytes, false);
+define_builder!(unicode, re_unicode, true);
+
+macro_rules! define_set_builder {
+ ($name:ident, $regex_mod:ident, $only_utf8:expr) => {
+ pub mod $name {
+ use super::RegexOptions;
+ use error::Error;
+ use exec::ExecBuilder;
+
+ use re_set::$regex_mod::RegexSet;
+
+ /// A configurable builder for a set of regular expressions.
+ ///
+ /// A builder can be used to configure how the regexes are built, for example,
+ /// by setting the default flags (which can be overridden in the expression
+ /// itself) or setting various limits.
+ pub struct RegexSetBuilder(RegexOptions);
+
+ impl RegexSetBuilder {
+ /// Create a new regular expression builder with the given pattern.
+ ///
+ /// If the pattern is invalid, then an error will be returned when
+ /// `build` is called.
+ pub fn new<I, S>(patterns: I) -> RegexSetBuilder
+ where
+ S: AsRef<str>,
+ I: IntoIterator<Item = S>,
+ {
+ let mut builder = RegexSetBuilder(RegexOptions::default());
+ for pat in patterns {
+ builder.0.pats.push(pat.as_ref().to_owned());
+ }
+ builder
+ }
+
+ /// Consume the builder and compile the regular expressions into a set.
+ pub fn build(&self) -> Result<RegexSet, Error> {
+ ExecBuilder::new_options(self.0.clone())
+ .only_utf8($only_utf8)
+ .build()
+ .map(RegexSet::from)
+ }
+
+ /// Set the value for the case insensitive (`i`) flag.
+ pub fn case_insensitive(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexSetBuilder {
+ self.0.case_insensitive = yes;
+ self
+ }
+
+ /// Set the value for the multi-line matching (`m`) flag.
+ pub fn multi_line(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexSetBuilder {
+ self.0.multi_line = yes;
+ self
+ }
+
+ /// Set the value for the any character (`s`) flag, where in `.` matches
+ /// anything when `s` is set and matches anything except for new line when
+ /// it is not set (the default).
+ ///
+ /// N.B. "matches anything" means "any byte" for `regex::bytes::RegexSet`
+ /// expressions and means "any Unicode scalar value" for `regex::RegexSet`
+ /// expressions.
+ pub fn dot_matches_new_line(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexSetBuilder {
+ self.0.dot_matches_new_line = yes;
+ self
+ }
+
+ /// Set the value for the greedy swap (`U`) flag.
+ pub fn swap_greed(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexSetBuilder {
+ self.0.swap_greed = yes;
+ self
+ }
+
+ /// Set the value for the ignore whitespace (`x`) flag.
+ pub fn ignore_whitespace(
+ &mut self,
+ yes: bool,
+ ) -> &mut RegexSetBuilder {
+ self.0.ignore_whitespace = yes;
+ self
+ }
+
+ /// Set the value for the Unicode (`u`) flag.
+ pub fn unicode(&mut self, yes: bool) -> &mut RegexSetBuilder {
+ self.0.unicode = yes;
+ 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 RegexSetBuilder {
+ self.0.octal = yes;
+ self
+ }
+
+ /// Set the approximate size limit of the compiled regular expression.
+ ///
+ /// This roughly corresponds to the number of bytes occupied by a single
+ /// compiled program. If the program exceeds this number, then a
+ /// compilation error is returned.
+ pub fn size_limit(
+ &mut self,
+ limit: usize,
+ ) -> &mut RegexSetBuilder {
+ self.0.size_limit = limit;
+ self
+ }
+
+ /// Set the approximate size of the cache used by the DFA.
+ ///
+ /// This roughly corresponds to the number of bytes that the DFA will
+ /// use while searching.
+ ///
+ /// Note that this is a *per thread* limit. There is no way to set a global
+ /// limit. In particular, if a regex is used from multiple threads
+ /// simultaneously, then each thread may use up to the number of bytes
+ /// specified here.
+ pub fn dfa_size_limit(
+ &mut self,
+ limit: usize,
+ ) -> &mut RegexSetBuilder {
+ self.0.dfa_size_limit = limit;
+ self
+ }
+
+ /// 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 RegexSetBuilder {
+ self.0.nest_limit = limit;
+ self
+ }
+ }
+ }
+ };
+}
+
+define_set_builder!(set_bytes, bytes, false);
+define_set_builder!(set_unicode, unicode, true);