Rust Requires Chilkat v11.1.0+

Regular Expression with Multiple Matches and Capture Groups

See more Regular Expressions Examples

Demonstrates a regular expression with multiple matches and capture groups for each match.

Note: Chilkat uses PCRE2. See PCRE2 Regular Expressions
Also see: PCRE2 Performance

Rust

let pattern = "Name:\\s+(\\w+)\\s+(\\w+),\\s+Email:\\s+(\\S+)".to_string();

let sb = chilkat::StringBuilder::new();
let crlf = true;
let _ = sb.append_line("Name: John Smith, Email: john.smith@example.com", crlf);
let _ = sb.append_line("Name: Jack Johnson, Email: jack.johnson@example.com", crlf);
let _ = sb.append_line("Name: Mary Adams, Email: mary.adams@example.com", crlf);

println!("{}", sb.get_as_string().unwrap_or_default());

// We have the following string:
// Name: John Smith, Email: john.smith@example.com
// Name: Jack Johnson, Email: jack.johnson@example.com
// Name: Mary Adams, Email: mary.adams@example.com

let json = chilkat::JsonObject::new();
json.set_emit_compact(false);

let timeout_ms = 2000;
let num_matches = sb.regex_match(&pattern, &json, timeout_ms);
if num_matches < 0 {
    // Probably an error in the regular expression.
    // Suggestion: Use AI to help create and/or diagnose regular expressions.
    println!("{}", sb.last_error_text());
    return;
}

// Examine the matches:
println!("{}", json.emit().unwrap_or_default());

// This is the JSON with the match information.
// See the JSON parsing code below to get the matched capture group values.

// {
//   "match": [
//     {
//       "group": [
//         {
//           "cap": "Name: John Smith, Email: john.smith@example.com",
//           "idx": 0,
//           "len": 47
//         },
//         {
//           "cap": "John",
//           "idx": 6,
//           "len": 4
//         },
//         {
//           "cap": "Smith",
//           "idx": 11,
//           "len": 5
//         },
//         {
//           "cap": "john.smith@example.com",
//           "idx": 25,
//           "len": 22
//         }
//       ]
//     },
//     {
//       "group": [
//         {
//           "cap": "Name: Jack Johnson, Email: jack.johnson@example.com",
//           "idx": 49,
//           "len": 51
//         },
//         {
//           "cap": "Jack",
//           "idx": 55,
//           "len": 4
//         },
//         {
//           "cap": "Johnson",
//           "idx": 60,
//           "len": 7
//         },
//         {
//           "cap": "jack.johnson@example.com",
//           "idx": 76,
//           "len": 24
//         }
//       ]
//     },
//     {
//       "group": [
//         {
//           "cap": "Name: Mary Adams, Email: mary.adams@example.com",
//           "idx": 102,
//           "len": 47
//         },
//         {
//           "cap": "Mary",
//           "idx": 108,
//           "len": 4
//         },
//         {
//           "cap": "Adams",
//           "idx": 113,
//           "len": 5
//         },
//         {
//           "cap": "mary.adams@example.com",
//           "idx": 127,
//           "len": 22
//         }
//       ]
//     }
//   ]
// }

// Important:  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

let mut cap = String::new();
let mut i = 0;
let match_count = json.size_of_array("match");
while i < match_count {
    println!("Match {}:", i + 1);
    json.set_i(i);
    let mut j = 0;
    let num_capture_groups = json.size_of_array("match[i].group");
    while j < num_capture_groups {
        json.set_j(j);
        cap = json.string_of("match[i].group[j].cap").unwrap_or_default();
        println!("{}: {}", j, cap);
        j = j + 1;
    }

    i = i + 1;
}

// Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

// Output

// Match 1:
// 0: Name: John Smith, Email: john.smith@example.com
// 1: John
// 2: Smith
// 3: john.smith@example.com
// Match 2:
// 0: Name: Jack Johnson, Email: jack.johnson@example.com
// 1: Jack
// 2: Johnson
// 3: jack.johnson@example.com
// Match 3:
// 0: Name: Mary Adams, Email: mary.adams@example.com
// 1: Mary
// 2: Adams
// 3: mary.adams@example.com