File size: 7,630 Bytes
72c0672 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 | use crate::utils::SysRegex;
use crate::{Offsets, Result};
use regex::Regex;
/// Pattern used to split a NormalizedString
pub trait Pattern {
/// Slice the given string in a list of pattern match positions, with
/// a boolean indicating whether this is a match or not.
///
/// This method *must* cover the whole string in its outputs, with
/// contiguous ordered slices.
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>>;
}
impl Pattern for char {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
let is_char = |c: char| -> bool { c == *self };
is_char.find_matches(inside)
}
}
impl Pattern for &str {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
if self.is_empty() {
// If we try to find the matches with an empty string, just don't match anything
return Ok(vec![((0, inside.chars().count()), false)]);
}
let re = Regex::new(®ex::escape(self))?;
(&re).find_matches(inside)
}
}
impl Pattern for &String {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
let s: &str = self;
s.find_matches(inside)
}
}
impl Pattern for &Regex {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
if inside.is_empty() {
return Ok(vec![((0, 0), false)]);
}
let mut prev = 0;
let mut splits = Vec::with_capacity(inside.len());
for m in self.find_iter(inside) {
if prev != m.start() {
splits.push(((prev, m.start()), false));
}
splits.push(((m.start(), m.end()), true));
prev = m.end();
}
if prev != inside.len() {
splits.push(((prev, inside.len()), false))
}
Ok(splits)
}
}
impl Pattern for &SysRegex {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
if inside.is_empty() {
return Ok(vec![((0, 0), false)]);
}
let mut prev = 0;
let mut splits = Vec::with_capacity(inside.len());
for (start, end) in self.find_iter(inside) {
if prev != start {
splits.push(((prev, start), false));
}
splits.push(((start, end), true));
prev = end;
}
if prev != inside.len() {
splits.push(((prev, inside.len()), false))
}
Ok(splits)
}
}
impl<F> Pattern for F
where
F: Fn(char) -> bool,
{
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
if inside.is_empty() {
return Ok(vec![((0, 0), false)]);
}
let mut last_offset = 0;
let mut last_seen = 0;
let mut matches = inside
.char_indices()
.flat_map(|(b, c)| {
last_seen = b + c.len_utf8();
if self(c) {
let mut events = Vec::with_capacity(2);
if last_offset < b {
// We need to emit what was before this match
events.push(((last_offset, b), false));
}
events.push(((b, b + c.len_utf8()), true));
last_offset = b + c.len_utf8();
events
} else {
vec![]
}
})
.collect::<Vec<_>>();
// Do not forget the last potential split
if last_seen > last_offset {
matches.push(((last_offset, last_seen), false));
}
Ok(matches)
}
}
/// Invert the `is_match` flags for the wrapped Pattern. This is usefull
/// for example when we use a regex that matches words instead of a delimiter,
/// and we want to match the delimiter.
pub struct Invert<P: Pattern>(pub P);
impl<P: Pattern> Pattern for Invert<P> {
fn find_matches(&self, inside: &str) -> Result<Vec<(Offsets, bool)>> {
Ok(self
.0
.find_matches(inside)?
.into_iter()
.map(|(offsets, flag)| (offsets, !flag))
.collect())
}
}
#[cfg(test)]
mod tests {
use super::*;
use regex::Regex;
macro_rules! do_test {
($inside: expr, $pattern: expr => @ERROR) => {
assert!($pattern.find_matches($inside).is_err());
};
($inside: expr, $pattern: expr => $result: expr) => {
assert_eq!($pattern.find_matches($inside).unwrap(), $result);
assert_eq!(
Invert($pattern).find_matches($inside).unwrap(),
$result
.into_iter()
.map(|v: (Offsets, bool)| (v.0, !v.1))
.collect::<Vec<_>>()
);
};
}
#[test]
fn char() {
do_test!("aba", 'a' => vec![((0, 1), true), ((1, 2), false), ((2, 3), true)]);
do_test!("bbbba", 'a' => vec![((0, 4), false), ((4, 5), true)]);
do_test!("aabbb", 'a' => vec![((0, 1), true), ((1, 2), true), ((2, 5), false)]);
do_test!("", 'a' => vec![((0, 0), false)]);
do_test!("aaa", 'b' => vec![((0, 3), false)]);
}
#[test]
fn str() {
do_test!("aba", "a" => vec![((0, 1), true), ((1, 2), false), ((2, 3), true)]);
do_test!("bbbba", "a" => vec![((0, 4), false), ((4, 5), true)]);
do_test!("aabbb", "a" => vec![((0, 1), true), ((1, 2), true), ((2, 5), false)]);
do_test!("aabbb", "ab" => vec![((0, 1), false), ((1, 3), true), ((3, 5), false)]);
do_test!("aabbab", "ab" =>
vec![((0, 1), false), ((1, 3), true), ((3, 4), false), ((4, 6), true)]
);
do_test!("", "" => vec![((0, 0), false)]);
do_test!("aaa", "" => vec![((0, 3), false)]);
do_test!("aaa", "b" => vec![((0, 3), false)]);
}
#[test]
fn functions() {
let is_b = |c| c == 'b';
do_test!("aba", is_b => vec![((0, 1), false), ((1, 2), true), ((2, 3), false)]);
do_test!("aaaab", is_b => vec![((0, 4), false), ((4, 5), true)]);
do_test!("bbaaa", is_b => vec![((0, 1), true), ((1, 2), true), ((2, 5), false)]);
do_test!("", is_b => vec![((0, 0), false)]);
do_test!("aaa", is_b => vec![((0, 3), false)]);
}
#[test]
fn regex() {
let is_whitespace = Regex::new(r"\s+").unwrap();
do_test!("a b", &is_whitespace => vec![((0, 1), false), ((1, 4), true), ((4, 5), false)]);
do_test!(" a b ", &is_whitespace =>
vec![((0, 3), true), ((3, 4), false), ((4, 7), true), ((7, 8), false), ((8, 11), true)]
);
do_test!("", &is_whitespace => vec![((0, 0), false)]);
do_test!("πΎπ π π ππ π£ππππ", &is_whitespace =>
vec![((0, 16), false), ((16, 17), true), ((17, 45), false)]
);
do_test!("aaa", &is_whitespace => vec![((0, 3), false)]);
}
#[test]
fn sys_regex() {
let is_whitespace = SysRegex::new(r"\s+").unwrap();
do_test!("a b", &is_whitespace => vec![((0, 1), false), ((1, 4), true), ((4, 5), false)]);
do_test!(" a b ", &is_whitespace =>
vec![((0, 3), true), ((3, 4), false), ((4, 7), true), ((7, 8), false), ((8, 11), true)]
);
do_test!("", &is_whitespace => vec![((0, 0), false)]);
do_test!("πΎπ π π ππ π£ππππ", &is_whitespace =>
vec![((0, 16), false), ((16, 17), true), ((17, 45), false)]
);
do_test!("aaa", &is_whitespace => vec![((0, 3), false)]);
}
}
|