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ripgrep/grep-matcher/tests/util.rs
Andrew Gallant d9ca529356 libripgrep: initial commit introducing libripgrep
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
2018-08-20 07:10:19 -04:00

105 lines
2.5 KiB
Rust

use std::collections::HashMap;
use std::result;
use grep_matcher::{Captures, Match, Matcher, NoCaptures, NoError};
use regex::bytes::{CaptureLocations, Regex};
#[derive(Debug)]
pub struct RegexMatcher {
pub re: Regex,
pub names: HashMap<String, usize>,
}
impl RegexMatcher {
pub fn new(re: Regex) -> RegexMatcher {
let mut names = HashMap::new();
for (i, optional_name) in re.capture_names().enumerate() {
if let Some(name) = optional_name {
names.insert(name.to_string(), i);
}
}
RegexMatcher {
re: re,
names: names,
}
}
}
type Result<T> = result::Result<T, NoError>;
impl Matcher for RegexMatcher {
type Captures = RegexCaptures;
type Error = NoError;
fn find_at(
&self,
haystack: &[u8],
at: usize,
) -> Result<Option<Match>> {
Ok(self.re
.find_at(haystack, at)
.map(|m| Match::new(m.start(), m.end())))
}
fn new_captures(&self) -> Result<RegexCaptures> {
Ok(RegexCaptures(self.re.capture_locations()))
}
fn captures_at(
&self,
haystack: &[u8],
at: usize,
caps: &mut RegexCaptures,
) -> Result<bool> {
Ok(self.re.captures_read_at(&mut caps.0, haystack, at).is_some())
}
fn capture_count(&self) -> usize {
self.re.captures_len()
}
fn capture_index(&self, name: &str) -> Option<usize> {
self.names.get(name).map(|i| *i)
}
// We purposely don't implement any other methods, so that we test the
// default impls. The "real" Regex impl for Matcher provides a few more
// impls. e.g., Its `find_iter` impl is faster than what we can do here,
// since the regex crate avoids synchronization overhead.
}
#[derive(Debug)]
pub struct RegexMatcherNoCaps(pub Regex);
impl Matcher for RegexMatcherNoCaps {
type Captures = NoCaptures;
type Error = NoError;
fn find_at(
&self,
haystack: &[u8],
at: usize,
) -> Result<Option<Match>> {
Ok(self.0
.find_at(haystack, at)
.map(|m| Match::new(m.start(), m.end())))
}
fn new_captures(&self) -> Result<NoCaptures> {
Ok(NoCaptures::new())
}
}
#[derive(Clone, Debug)]
pub struct RegexCaptures(CaptureLocations);
impl Captures for RegexCaptures {
fn len(&self) -> usize {
self.0.len()
}
fn get(&self, i: usize) -> Option<Match> {
self.0.pos(i).map(|(s, e)| Match::new(s, e))
}
}