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
// Copyright 2021-2023 The Jujutsu Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//! String helpers.
use std::borrow::{Borrow, Cow};
use std::collections::BTreeMap;
use std::fmt;
use either::Either;
use thiserror::Error;
/// Error occurred during pattern string parsing.
#[derive(Debug, Error)]
pub enum StringPatternParseError {
/// Unknown pattern kind is specified.
#[error(r#"Invalid string pattern kind "{0}""#)]
InvalidKind(String),
/// Failed to parse glob pattern.
#[error(transparent)]
GlobPattern(glob::PatternError),
}
/// Pattern to be tested against string property like commit description or
/// branch name.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum StringPattern {
/// Matches strings exactly equal to `string`.
Exact(String),
/// Unix-style shell wildcard pattern.
Glob(glob::Pattern),
/// Matches strings that contain `substring`.
Substring(String),
}
impl StringPattern {
/// Pattern that matches any string.
pub const fn everything() -> Self {
StringPattern::Substring(String::new())
}
/// Creates pattern that matches exactly.
pub fn exact(src: impl Into<String>) -> Self {
StringPattern::Exact(src.into())
}
/// Parses the given string as glob pattern.
pub fn glob(src: &str) -> Result<Self, StringPatternParseError> {
// TODO: might be better to do parsing and compilation separately since
// not all backends would use the compiled pattern object.
// TODO: if no meta character found, it can be mapped to Exact.
let pattern = glob::Pattern::new(src).map_err(StringPatternParseError::GlobPattern)?;
Ok(StringPattern::Glob(pattern))
}
/// Parses the given string as pattern of the specified `kind`.
pub fn from_str_kind(src: &str, kind: &str) -> Result<Self, StringPatternParseError> {
match kind {
"exact" => Ok(StringPattern::exact(src)),
"glob" => StringPattern::glob(src),
"substring" => Ok(StringPattern::Substring(src.to_owned())),
_ => Err(StringPatternParseError::InvalidKind(kind.to_owned())),
}
}
/// Returns true if this pattern matches input strings exactly.
pub fn is_exact(&self) -> bool {
self.as_exact().is_some()
}
/// Returns a literal pattern if this should match input strings exactly.
///
/// This can be used to optimize map lookup by exact key.
pub fn as_exact(&self) -> Option<&str> {
match self {
StringPattern::Exact(literal) => Some(literal),
StringPattern::Glob(_) | StringPattern::Substring(_) => None,
}
}
/// Returns the original string of this pattern.
pub fn as_str(&self) -> &str {
match self {
StringPattern::Exact(literal) => literal,
StringPattern::Glob(pattern) => pattern.as_str(),
StringPattern::Substring(needle) => needle,
}
}
/// Converts this pattern to a glob string. Returns `None` if the pattern
/// can't be represented as a glob.
pub fn to_glob(&self) -> Option<Cow<'_, str>> {
// TODO: If we add Regex pattern, it will return None.
match self {
StringPattern::Exact(literal) => Some(glob::Pattern::escape(literal).into()),
StringPattern::Glob(pattern) => Some(pattern.as_str().into()),
StringPattern::Substring(needle) if needle.is_empty() => Some("*".into()),
StringPattern::Substring(needle) => {
Some(format!("*{}*", glob::Pattern::escape(needle)).into())
}
}
}
/// Returns true if this pattern matches the `haystack`.
pub fn matches(&self, haystack: &str) -> bool {
match self {
StringPattern::Exact(literal) => haystack == literal,
StringPattern::Glob(pattern) => pattern.matches(haystack),
StringPattern::Substring(needle) => haystack.contains(needle),
}
}
/// Iterates entries of the given `map` whose keys matches this pattern.
pub fn filter_btree_map<'a: 'b, 'b, K: Borrow<str> + Ord, V>(
&'b self,
map: &'a BTreeMap<K, V>,
) -> impl Iterator<Item = (&'a K, &'a V)> + 'b {
if let Some(key) = self.as_exact() {
Either::Left(map.get_key_value(key).into_iter())
} else {
Either::Right(map.iter().filter(|&(key, _)| self.matches(key.borrow())))
}
}
}
impl fmt::Display for StringPattern {
/// Shows the original string of this pattern.
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.as_str())
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_string_pattern_to_glob() {
assert_eq!(StringPattern::everything().to_glob(), Some("*".into()));
assert_eq!(StringPattern::exact("a").to_glob(), Some("a".into()));
assert_eq!(StringPattern::exact("*").to_glob(), Some("[*]".into()));
assert_eq!(
StringPattern::glob("*").unwrap().to_glob(),
Some("*".into())
);
assert_eq!(
StringPattern::Substring("a".into()).to_glob(),
Some("*a*".into())
);
assert_eq!(
StringPattern::Substring("*".into()).to_glob(),
Some("*[*]*".into())
);
}
}