rust/ripgrep
1
0
Fork 0
mirror of https://github.com/BurntSushi/ripgrep.git synced 2025-06-14 22:15:13 +02:00
Code Issues Releases Activity

libripgrep: initial commit introducing libripgrep

Browse Source 
libripgrep is not any one library, but rather, a collection of libraries
that roughly separate the following key distinct phases in a grep
implementation:

  1. Pattern matching (e.g., by a regex engine).
  2. Searching a file using a pattern matcher.
  3. Printing results.

Ultimately, both (1) and (3) are defined by de-coupled interfaces, of
which there may be multiple implementations. Namely, (1) is satisfied by
the `Matcher` trait in the `grep-matcher` crate and (3) is satisfied by
the `Sink` trait in the `grep2` crate. The searcher (2) ties everything
together and finds results using a matcher and reports those results
using a `Sink` implementation.

Closes #162
This commit is contained in:
Andrew Gallant
2018-04-29 09:29:52 -04:00
parent 0958837ee1
commit d9ca529356
68 changed files with 18010 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
grep-pcre2/src/error.rs Normal file
View File

@ -0,0 +1,59 @@
use std::error;
use std::fmt;
/// An error that can occur in this crate.
///
/// Generally, this error corresponds to problems building a regular
/// expression, whether it's in parsing, compilation or a problem with
/// guaranteeing a configured optimization.
#[derive(Clone, Debug)]
pub struct Error {
kind: ErrorKind,
}
impl Error {
pub(crate) fn regex<E: error::Error>(err: E) -> Error {
Error { kind: ErrorKind::Regex(err.to_string()) }
}
/// Return the kind of this error.
pub fn kind(&self) -> &ErrorKind {
&self.kind
}
}
/// The kind of an error that can occur.
#[derive(Clone, Debug)]
pub enum ErrorKind {
/// An error that occurred as a result of parsing a regular expression.
/// This can be a syntax error or an error that results from attempting to
/// compile a regular expression that is too big.
///
/// The string here is the underlying error converted to a string.
Regex(String),
/// Hints that destructuring should not be exhaustive.
///
/// This enum may grow additional variants, so this makes sure clients
/// don't count on exhaustive matching. (Otherwise, adding a new variant
/// could break existing code.)
#[doc(hidden)]
__Nonexhaustive,
}
impl error::Error for Error {
fn description(&self) -> &str {
match self.kind {
ErrorKind::Regex(_) => "regex error",
ErrorKind::__Nonexhaustive => unreachable!(),
}
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self.kind {
ErrorKind::Regex(ref s) => write!(f, "{}", s),
ErrorKind::__Nonexhaustive => unreachable!(),
}
}
}

15
grep-pcre2/src/lib.rs Normal file
View File

@ -0,0 +1,15 @@
/*!
An implementation of `grep-matcher`'s `Matcher` trait for
[PCRE2](https://www.pcre.org/).
*/
#![deny(missing_docs)]
extern crate grep_matcher;
extern crate pcre2;
pub use error::{Error, ErrorKind};
pub use matcher::{RegexCaptures, RegexMatcher, RegexMatcherBuilder};
mod error;
mod matcher;

425
grep-pcre2/src/matcher.rs Normal file
View File

@ -0,0 +1,425 @@
use std::collections::HashMap;
use grep_matcher::{Captures, Match, Matcher};
use pcre2::bytes::{CaptureLocations, Regex, RegexBuilder};
use error::Error;
/// A builder for configuring the compilation of a PCRE2 regex.
#[derive(Clone, Debug)]
pub struct RegexMatcherBuilder {
builder: RegexBuilder,
case_smart: bool,
word: bool,
}
impl RegexMatcherBuilder {
/// Create a new matcher builder with a default configuration.
pub fn new() -> RegexMatcherBuilder {
RegexMatcherBuilder {
builder: RegexBuilder::new(),
case_smart: false,
word: false,
}
}
/// Compile the given pattern into a PCRE matcher using the current
/// configuration.
///
/// If there was a problem compiling the pattern, then an error is
/// returned.
pub fn build(&self, pattern: &str) -> Result<RegexMatcher, Error> {
let mut builder = self.builder.clone();
if self.case_smart && !has_uppercase_literal(pattern) {
builder.caseless(true);
}
let res =
if self.word {
let pattern = format!(r"(?<!\w)(?:{})(?!\w)", pattern);
builder.build(&pattern)
} else {
builder.build(pattern)
};
res.map_err(Error::regex).map(|regex| {
let mut names = HashMap::new();
for (i, name) in regex.capture_names().iter().enumerate() {
if let Some(ref name) = *name {
names.insert(name.to_string(), i);
}
}
RegexMatcher { regex, names }
})
}
/// Enables case insensitive matching.
///
/// If the `utf` option is also set, then Unicode case folding is used
/// to determine case insensitivity. When the `utf` option is not set,
/// then only standard ASCII case insensitivity is considered.
///
/// This option corresponds to the `i` flag.
pub fn caseless(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.caseless(yes);
self
}
/// Whether to enable "smart case" or not.
///
/// When smart case is enabled, the builder will automatically enable
/// case insensitive matching based on how the pattern is written. Namely,
/// case insensitive mode is enabled when both of the following things
/// are believed to be true:
///
/// 1. The pattern contains at least one literal character. For example,
/// `a\w` contains a literal (`a`) but `\w` does not.
/// 2. Of the literals in the pattern, none of them are considered to be
/// uppercase according to Unicode. For example, `foo\pL` has no
/// uppercase literals but `Foo\pL` does.
///
/// Note that the implementation of this is not perfect. Namely, `\p{Ll}`
/// will prevent case insensitive matching even though it is part of a meta
/// sequence. This bug will probably never be fixed.
pub fn case_smart(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.case_smart = yes;
self
}
/// Enables "dot all" matching.
///
/// When enabled, the `.` metacharacter in the pattern matches any
/// character, include `\n`. When disabled (the default), `.` will match
/// any character except for `\n`.
///
/// This option corresponds to the `s` flag.
pub fn dotall(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.dotall(yes);
self
}
/// Enable "extended" mode in the pattern, where whitespace is ignored.
///
/// This option corresponds to the `x` flag.
pub fn extended(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.extended(yes);
self
}
/// Enable multiline matching mode.
///
/// When enabled, the `^` and `$` anchors will match both at the beginning
/// and end of a subject string, in addition to matching at the start of
/// a line and the end of a line. When disabled, the `^` and `$` anchors
/// will only match at the beginning and end of a subject string.
///
/// This option corresponds to the `m` flag.
pub fn multi_line(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.multi_line(yes);
self
}
/// Enable matching of CRLF as a line terminator.
///
/// When enabled, anchors such as `^` and `$` will match any of the
/// following as a line terminator: `\r`, `\n` or `\r\n`.
///
/// This is disabled by default, in which case, only `\n` is recognized as
/// a line terminator.
pub fn crlf(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.crlf(yes);
self
}
/// Require that all matches occur on word boundaries.
///
/// Enabling this option is subtly different than putting `\b` assertions
/// on both sides of your pattern. In particular, a `\b` assertion requires
/// that one side of it match a word character while the other match a
/// non-word character. This option, in contrast, merely requires that
/// one side match a non-word character.
///
/// For example, `\b-2\b` will not match `foo -2 bar` since `-` is not a
/// word character. However, `-2` with this `word` option enabled will
/// match the `-2` in `foo -2 bar`.
pub fn word(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.word = yes;
self
}
/// Enable Unicode matching mode.
///
/// When enabled, the following patterns become Unicode aware: `\b`, `\B`,
/// `\d`, `\D`, `\s`, `\S`, `\w`, `\W`.
///
/// When set, this implies UTF matching mode. It is not possible to enable
/// Unicode matching mode without enabling UTF matching mode.
///
/// This is disabled by default.
pub fn ucp(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.ucp(yes);
self
}
/// Enable UTF matching mode.
///
/// When enabled, characters are treated as sequences of code units that
/// make up a single codepoint instead of as single bytes. For example,
/// this will cause `.` to match any single UTF-8 encoded codepoint, where
/// as when this is disabled, `.` will any single byte (except for `\n` in
/// both cases, unless "dot all" mode is enabled).
///
/// Note that when UTF matching mode is enabled, every search performed
/// will do a UTF-8 validation check, which can impact performance. The
/// UTF-8 check can be disabled via the `disable_utf_check` option, but it
/// is undefined behavior to enable UTF matching mode and search invalid
/// UTF-8.
///
/// This is disabled by default.
pub fn utf(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.utf(yes);
self
}
/// When UTF matching mode is enabled, this will disable the UTF checking
/// that PCRE2 will normally perform automatically. If UTF matching mode
/// is not enabled, then this has no effect.
///
/// UTF checking is enabled by default when UTF matching mode is enabled.
/// If UTF matching mode is enabled and UTF checking is enabled, then PCRE2
/// will return an error if you attempt to search a subject string that is
/// not valid UTF-8.
///
/// # Safety
///
/// It is undefined behavior to disable the UTF check in UTF matching mode
/// and search a subject string that is not valid UTF-8. When the UTF check
/// is disabled, callers must guarantee that the subject string is valid
/// UTF-8.
pub unsafe fn disable_utf_check(&mut self) -> &mut RegexMatcherBuilder {
self.builder.disable_utf_check();
self
}
/// Enable PCRE2's JIT.
///
/// This generally speeds up matching quite a bit. The downside is that it
/// can increase the time it takes to compile a pattern.
///
/// This is disabled by default.
pub fn jit(&mut self, yes: bool) -> &mut RegexMatcherBuilder {
self.builder.jit(yes);
self
}
}
/// An implementation of the `Matcher` trait using PCRE2.
#[derive(Clone, Debug)]
pub struct RegexMatcher {
regex: Regex,
names: HashMap<String, usize>,
}
impl RegexMatcher {
/// Create a new matcher from the given pattern using the default
/// configuration.
pub fn new(pattern: &str) -> Result<RegexMatcher, Error> {
RegexMatcherBuilder::new().build(pattern)
}
}
impl Matcher for RegexMatcher {
type Captures = RegexCaptures;
type Error = Error;
fn find_at(
&self,
haystack: &[u8],
at: usize,
) -> Result<Option<Match>, Error> {
Ok(self.regex
.find_at(haystack, at)
.map_err(Error::regex)?
.map(|m| Match::new(m.start(), m.end())))
}
fn new_captures(&self) -> Result<RegexCaptures, Error> {
Ok(RegexCaptures::new(self.regex.capture_locations()))
}
fn capture_count(&self) -> usize {
self.regex.captures_len()
}
fn capture_index(&self, name: &str) -> Option<usize> {
self.names.get(name).map(|i| *i)
}
fn try_find_iter<F, E>(
&self,
haystack: &[u8],
mut matched: F,
) -> Result<Result<(), E>, Error>
where F: FnMut(Match) -> Result<bool, E>
{
for result in self.regex.find_iter(haystack) {
let m = result.map_err(Error::regex)?;
match matched(Match::new(m.start(), m.end())) {
Ok(true) => continue,
Ok(false) => return Ok(Ok(())),
Err(err) => return Ok(Err(err)),
}
}
Ok(Ok(()))
}
fn captures_at(
&self,
haystack: &[u8],
at: usize,
caps: &mut RegexCaptures,
) -> Result<bool, Error> {
Ok(self.regex
.captures_read_at(&mut caps.locs, haystack, at)
.map_err(Error::regex)?
.is_some())
}
}
/// Represents the match offsets of each capturing group in a match.
///
/// The first, or `0`th capture group, always corresponds to the entire match
/// and is guaranteed to be present when a match occurs. The next capture
/// group, at index `1`, corresponds to the first capturing group in the regex,
/// ordered by the position at which the left opening parenthesis occurs.
///
/// Note that not all capturing groups are guaranteed to be present in a match.
/// For example, in the regex, `(?P<foo>\w)|(?P<bar>\W)`, only one of `foo`
/// or `bar` will ever be set in any given match.
///
/// In order to access a capture group by name, you'll need to first find the
/// index of the group using the corresponding matcher's `capture_index`
/// method, and then use that index with `RegexCaptures::get`.
#[derive(Clone, Debug)]
pub struct RegexCaptures {
/// Where the locations are stored.
locs: CaptureLocations,
}
impl Captures for RegexCaptures {
fn len(&self) -> usize {
self.locs.len()
}
fn get(&self, i: usize) -> Option<Match> {
self.locs.get(i).map(|(s, e)| Match::new(s, e))
}
}
impl RegexCaptures {
pub(crate) fn new(locs: CaptureLocations) -> RegexCaptures {
RegexCaptures { locs }
}
}
/// Determine whether the pattern contains an uppercase character which should
/// negate the effect of the smart-case option.
///
/// Ideally we would be able to check the AST in order to correctly handle
/// things like '\p{Ll}' and '\p{Lu}' (which should be treated as explicitly
/// cased), but PCRE doesn't expose enough details for that kind of analysis.
/// For now, our 'good enough' solution is to simply perform a semi-naïve
/// scan of the input pattern and ignore all characters following a '\'. The
/// This at least lets us support the most common cases, like 'foo\w' and
/// 'foo\S', in an intuitive manner.
fn has_uppercase_literal(pattern: &str) -> bool {
let mut chars = pattern.chars();
while let Some(c) = chars.next() {
if c == '\\' {
chars.next();
} else if c.is_uppercase() {
return true;
}
}
false
}
#[cfg(test)]
mod tests {
use grep_matcher::{LineMatchKind, Matcher};
use super::*;
// Test that enabling word matches does the right thing and demonstrate
// the difference between it and surrounding the regex in `\b`.
#[test]
fn word() {
let matcher = RegexMatcherBuilder::new()
.word(true)
.build(r"-2")
.unwrap();
assert!(matcher.is_match(b"abc -2 foo").unwrap());
let matcher = RegexMatcherBuilder::new()
.word(false)
.build(r"\b-2\b")
.unwrap();
assert!(!matcher.is_match(b"abc -2 foo").unwrap());
}
// Test that enabling CRLF permits `$` to match at the end of a line.
#[test]
fn line_terminator_crlf() {
// Test normal use of `$` with a `\n` line terminator.
let matcher = RegexMatcherBuilder::new()
.multi_line(true)
.build(r"abc$")
.unwrap();
assert!(matcher.is_match(b"abc\n").unwrap());
// Test that `$` doesn't match at `\r\n` boundary normally.
let matcher = RegexMatcherBuilder::new()
.multi_line(true)
.build(r"abc$")
.unwrap();
assert!(!matcher.is_match(b"abc\r\n").unwrap());
// Now check the CRLF handling.
let matcher = RegexMatcherBuilder::new()
.multi_line(true)
.crlf(true)
.build(r"abc$")
.unwrap();
assert!(matcher.is_match(b"abc\r\n").unwrap());
}
// Test that smart case works.
#[test]
fn case_smart() {
let matcher = RegexMatcherBuilder::new()
.case_smart(true)
.build(r"abc")
.unwrap();
assert!(matcher.is_match(b"ABC").unwrap());
let matcher = RegexMatcherBuilder::new()
.case_smart(true)
.build(r"aBc")
.unwrap();
assert!(!matcher.is_match(b"ABC").unwrap());
}
// Test that finding candidate lines works as expected.
#[test]
fn candidate_lines() {
fn is_confirmed(m: LineMatchKind) -> bool {
match m {
LineMatchKind::Confirmed(_) => true,
_ => false,
}
}
let matcher = RegexMatcherBuilder::new()
.build(r"\wfoo\s")
.unwrap();
let m = matcher.find_candidate_line(b"afoo ").unwrap().unwrap();
assert!(is_confirmed(m));
}
}