Question

在自由范围文本中拉引号并不少见。假设我们想要识别拉引号，即使它们嵌套在一个句子中。例如，假设我们有一个带有嵌套拉引号的字符串：

一二“三四”五六“七八”九“十一一”

是否有一个java正则表达式找到以下3组：

三四
七八“九”十一十一
的 9

Answer 1

根据Wiktor的建议，我提出了以下建议。虽然没有任何优雅，但这似乎可以解决问题：

public List<String> parseNestedSingleQuotes(String text) {
    return parseNestedQuotes(text,'\'','{');
}

public List<String> parseNestedDoubleQuotes(String text) {
    return parseNestedQuotes(text,'"','{');
}

public List<String> parseNestedQuotes(String text,char quoteChar,char markChar) {
    List<String> groups = new ArrayList<String>();
    char[] charArray = text.toCharArray();

    Matcher m = Pattern.compile("("+quoteChar+")\\w",Pattern.CASE_INSENSITIVE).matcher(text);
    while( m.find() ) {
        charArray[m.start()] = markChar;
    }
    //System.out.println("debug charArray with marks: " + new String(charArray));

    m = Pattern.compile("\\w("+quoteChar+")",Pattern.CASE_INSENSITIVE).matcher(text);
    while( m.find() ) {
        int endIdx = m.start()+1;
        int startIdx = unmarkLastIndexOf(charArray,endIdx,quoteChar,markChar);
        if( startIdx != -1 ) {
            groups.add(text.substring(startIdx+1,endIdx));
        }
    }
    return groups;
}

int unmarkLastIndexOf(char[] charArray, int endIdx, char quoteChar, char markChar) {
    String template = new String(charArray);
    int idx = template.lastIndexOf(markChar,endIdx-1);
    if( idx != -1 ) {
        charArray[idx] = quoteChar;
        return idx;
    }
    return -1;
}

以下是一些测试用例

void test_parseNestedQuotes()
{
    String input = "zero 'one two' three 'four five 'six seven' eight' nine";
    System.out.println("nested singleQuote input: " + input);
    List<String>groups = parseNestedSingleQuotes(input);
    System.out.println("nested singleQuote groups:");
    printListOfString(groups);
    assert groups.size() == 3;
    System.out.println("--------");

    input = "one two \"three four\" five six \"seven eight \"nine\" ten eleven\" twelve";
    System.out.println("nested doubleQuote input: " + input);
    groups = parseNestedDoubleQuotes(input);
    System.out.println("nested doubleQuote groups:");
    printListOfString(groups);
    assert groups.size() == 3;
    System.out.println("--------");

    input = "one two \"three four\" five six \"seven eight \"nine\" ten eleven twelve";
    System.out.println("nested doubleQuote input with unmatched pairs: " + input);
    groups = parseNestedDoubleQuotes(input);
    System.out.println("nested doubleQuote groups from unmatched pairs:");
    printListOfString(groups);
    assert groups.size() == 2;
    System.out.println("--------");

    input = "one two (three four) five six";
    System.out.println("no doubleQuote input with parens: " + input);
    groups = parseNestedDoubleQuotes(input);
    System.out.println("no doubleQuote groups from paren pairs:");
    printListOfString(groups);
    assert groups.size() == 0;
    System.out.println("--------");
}

void printListOfString(List<String> list) { 
    for( String string : list )
        System.out.println(string);
}

输出

nested singleQuote input: zero 'one two' three 'four five 'six seven' eight' nine
nested singleQuote groups:
one two
six seven
four five 'six seven' eight
--------
nested doubleQuote input: one two "three four" five six "seven eight "nine" ten eleven" twelve
nested doubleQuote groups:
three four
nine
seven eight "nine" ten eleven
--------
nested doubleQuote input with unmatched pairs: one two "three four" five six "seven eight "nine" ten eleven twelve
nested doubleQuote groups from unmatched pairs:
three four
nine
--------
no doubleQuote input with parens: one two (three four) five six
no doubleQuote groups from paren pairs:
--------

有任何改进建议吗？

嵌套引号

1 个答案: