regress 0.11.0

A regular expression engine targeting EcmaScript syntax
Documentation 
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240

//! Tests for Pattern trait implementation

#![cfg(feature = "pattern")]
#![feature(pattern)]

use regress::Regex;

#[test]
fn test_pattern_find() {
    let re = Regex::new(r"\d+").unwrap();
    let text = "abc123def456ghi";

    // Test with &Regex
    assert_eq!(text.find(&re), Some(3));

    // Test another pattern
    let re2 = Regex::new(r"def").unwrap();
    assert_eq!(text.find(&re2), Some(6));
}

#[test]
fn test_pattern_contains() {
    let re = Regex::new(r"\d+").unwrap();

    assert!(!"abc".contains(&re));
    assert!("abc123".contains(&re));
    assert!("123abc".contains(&re));
    assert!("abc123def".contains(&re));
}

#[test]
fn test_pattern_starts_with() {
    let re = Regex::new(r"\d+").unwrap();

    assert!(!"abc123".starts_with(&re));
    assert!("123abc".starts_with(&re));
    assert!("456".starts_with(&re));
}

#[test]
fn test_pattern_ends_with() {
    let re = Regex::new(r"\d+").unwrap();

    assert!(!"123abc".ends_with(&re));
    assert!("abc123".ends_with(&re));
    assert!("456".ends_with(&re));
}

#[test]
fn test_pattern_split() {
    let re = Regex::new(r"\s+").unwrap();
    let text = "hello    world\t\nfoo  bar";

    let parts: Vec<&str> = text.split(&re).collect();
    assert_eq!(parts, vec!["hello", "world", "foo", "bar"]);
}

#[test]
fn test_pattern_split_inclusive() {
    let re = Regex::new(r"\s+").unwrap();
    let text = "hello world foo";

    let parts: Vec<&str> = text.split_inclusive(&re).collect();
    assert_eq!(parts, vec!["hello ", "world ", "foo"]);
}

#[test]
fn test_pattern_matches() {
    let re = Regex::new(r"\w+").unwrap();
    let text = "hello world 123 test";

    let matches: Vec<&str> = text.matches(&re).collect();
    assert_eq!(matches, vec!["hello", "world", "123", "test"]);
}

#[test]
fn test_pattern_match_indices() {
    let re = Regex::new(r"\d+").unwrap();
    let text = "abc123def456ghi";

    let indices: Vec<(usize, &str)> = text.match_indices(&re).collect();
    assert_eq!(indices, vec![(3, "123"), (9, "456")]);
}

#[test]
fn test_pattern_replacen() {
    let re = Regex::new(r"\d+").unwrap();
    let text = "abc123def456ghi789";

    let result = text.replacen(&re, "XXX", 2);
    assert_eq!(result, "abcXXXdefXXXghi789");
}

#[test]
fn test_pattern_replace() {
    let re = Regex::new(r"\d+").unwrap();
    let text = "abc123def456ghi789";

    let result = text.replace(&re, "XXX");
    assert_eq!(result, "abcXXXdefXXXghiXXX");
}

#[test]
fn test_pattern_strip_prefix() {
    let re = Regex::new(r"\d+").unwrap();

    assert_eq!("123abc".strip_prefix(&re), Some("abc"));
    assert_eq!("abc123".strip_prefix(&re), None);
    assert_eq!("456def789".strip_prefix(&re), Some("def789"));
}

#[test]
fn test_pattern_strip_suffix() {
    let re = Regex::new(r"\d+").unwrap();

    assert_eq!("abc123".strip_suffix(&re), Some("abc"));
    assert_eq!("123abc".strip_suffix(&re), None);
    assert_eq!("789def456".strip_suffix(&re), Some("789def"));
}

#[test]
fn test_pattern_with_anchors() {
    let re = Regex::new(r"^\d+").unwrap();
    let text = "123abc456";

    assert_eq!(text.find(&re), Some(0));
    assert!(text.starts_with(&re));
    assert!(!text.ends_with(&re));
}

#[test]
fn test_pattern_zero_width_match() {
    let re = Regex::new(r"\b").unwrap(); // word boundary
    let text = "hello world";

    // Test that we can find word boundaries
    assert_eq!(text.find(&re), Some(0));

    // Test simple contains instead of matches to avoid infinite loop
    assert!(text.contains(&re));
}

#[test]
fn test_pattern_overlapping_pattern() {
    let re = Regex::new(r"aa").unwrap();
    let text = "aaaa";

    // Should find non-overlapping matches
    let matches: Vec<&str> = text.matches(&re).collect();
    assert_eq!(matches, vec!["aa", "aa"]);
}

#[test]
fn test_pattern_empty_regex() {
    let re = Regex::new(r"").unwrap();
    let text = "abc";

    // Empty regex should match at the beginning
    assert_eq!(text.find(&re), Some(0));
    assert!(text.contains(&re));

    // Test starts_with instead of matches to avoid infinite loop
    assert!(text.starts_with(&re));
}

#[test]
fn test_pattern_case_insensitive() {
    let re = Regex::with_flags(r"hello", "i").unwrap();
    let text = "HELLO world Hello";

    assert!(text.contains(&re));
    let matches: Vec<&str> = text.matches(&re).collect();
    assert_eq!(matches, vec!["HELLO", "Hello"]);
}

#[test]
fn test_pattern_multiline() {
    let re = Regex::with_flags(r"^test", "m").unwrap();
    let text = "hello\ntest world\ntest again";

    let matches: Vec<&str> = text.matches(&re).collect();
    assert_eq!(matches, vec!["test", "test"]);
}

#[test]
fn test_pattern_no_match() {
    let re = Regex::new(r"\d+").unwrap();
    let text = "hello world";

    assert_eq!(text.find(&re), None);
    assert!(!text.contains(&re));
    assert!(!text.starts_with(&re));
    assert!(!text.ends_with(&re));

    let matches: Vec<&str> = text.matches(&re).collect();
    assert!(matches.is_empty());
}

#[test]
fn test_pattern_comprehensive_example() {
    // This test demonstrates the various str methods that work with Pattern
    let text = "The year 2023 was followed by 2024, and then 2025.";
    let year_regex = Regex::new(r"\d{4}").unwrap();

    // Basic pattern operations
    assert!(text.contains(&year_regex));
    assert_eq!(text.find(&year_regex), Some(9)); // Position of "2023"
    assert!(!text.starts_with(&year_regex));
    assert!(!text.ends_with(&year_regex));

    // Find all years
    let years: Vec<&str> = text.matches(&year_regex).collect();
    assert_eq!(years, vec!["2023", "2024", "2025"]);

    // Find year positions
    let positions: Vec<(usize, &str)> = text.match_indices(&year_regex).collect();
    // "The year 2023 was followed by 2024, and then 2025."
    //  0123456789012345678901234567890123456789012345678901
    //           ^                    ^              ^
    //           9                   30             45
    assert_eq!(positions, vec![(9, "2023"), (30, "2024"), (45, "2025")]);

    // Split on years
    let parts: Vec<&str> = text.split(&year_regex).collect();
    assert_eq!(
        parts,
        vec!["The year ", " was followed by ", ", and then ", "."]
    );

    // Replace years
    let masked = text.replace(&year_regex, "YEAR");
    assert_eq!(masked, "The year YEAR was followed by YEAR, and then YEAR.");

    // Replace first two years only
    let partial = text.replacen(&year_regex, "XXXX", 2);
    assert_eq!(
        partial,
        "The year XXXX was followed by XXXX, and then 2025."
    );
}