Lab3.java

import java.util.regex.*;

public class Lab3 {
    private static void test_match(String text) {
        String stringLiteral = "`(?:(?:`{2})|(?:[^`])|(?:\\n))*`";  // correct
        String numLiteral = "[01]+b|[0-9]+";                        // correct
        String ident = "[\\?\\*\\|][0-9\\?\\*\\|]*";                // correct?
        String pattern = "(^" + stringLiteral + ")|(^" + numLiteral + ")|(^" + ident + ")";

        Pattern p = Pattern.compile(pattern);
        Matcher m = p.matcher(text);

        while (m.find()) {
            if (m.group(1) != null) {
                System.out.println("STRING LITERAL (" + m.start() + ":" + ")" + m.group(1));
            } else if (m.group(2) != null) {
                System.out.println("NUMBER LITERAL (" + m.start() + ":" + ")" + m.group(2));
            } else if (m.group(3) != null) {
                System.out.println("IDENT (" + m.start() + ":" + ")" + m.group(3));
            }
        }

        System.out.println("ERROR");
    }

    public static void main(String args[]) {
        test_match("100b 09842 ?87897124");
    }
}