Swift

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

Swift

func chilkatTest() {
    var success: Bool = false

    var pattern: String? = "Name:\\s+(\\w+)\\s+(\\w+),\\s+Email:\\s+(\\S+)"

    let sb = CkoStringBuilder()!
    var crlf: Bool = true
    sb.appendLine(str: "Name: John Smith, Email: john.smith@example.com", crlf: crlf)
    sb.appendLine(str: "Name: Jack Johnson, Email: jack.johnson@example.com", crlf: crlf)
    sb.appendLine(str: "Name: Mary Adams, Email: mary.adams@example.com", crlf: crlf)

    print("\(sb.getAsString()!)")

    // 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 = CkoJsonObject()!
    json.emitCompact = false

    var timeoutMs: Int = 2000
    var numMatches: Int = sb.regexMatch(pattern: pattern, json: json, timeoutMs: timeoutMs).intValue
    if numMatches < 0 {
        // Probably an error in the regular expression.
        // Suggestion: Use AI to help create and/or diagnose regular expressions.
        print("\(sb.lastErrorText!)")
        return
    }

    // Examine the matches:
    print("\(json.emit()!)")

    // 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.

    var cap: String?
    var i: Int = 0
    var matchCount: Int = json.size(ofArray: "match").intValue
    while i < matchCount {
        print("Match \(i + 1):")
        json.i = i
        var j: Int = 0
        var numCaptureGroups: Int = json.size(ofArray: "match[i].group").intValue
        while j < numCaptureGroups {
            json.j = j
            cap = json.string(of: "match[i].group[j].cap")
            print("\(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.co

}