Question

我正在使用C＃从Winforms RichTextBox派生的代码编辑器。我已经实现了自动完成和语法高亮，但代码折叠有点不同。我想要实现的是：

以下代码：

public static SomeFunction(EventArgs e)
{
    //Some code
    //Some code
    //Some code
    //Some code
    //Some code
    //Some code
}

应该成为：

public static SomeFunction(EventArgs e)[...]

[...]是您在[...]处悬停时在工具提示中显示的缩短代码任何想法或建议如何使用正则表达式或程序代码？

Answer 1

我创建了一个解析器，它将返回代码折叠位置的索引。

折叠分隔符由正则表达式定义。
您可以指定开始和结束索引，这样您就不必在更新某个区域时检查整个代码。
如果代码格式不正确，它将抛出异常，随时可以更改该行为。一种替代方案可能是它一直向上移动堆栈，直到找到合适的结束令牌。

折叠查找器

public class FoldFinder
{
    public static FoldFinder Instance { get; private set; }

    static FoldFinder()
    {
        Instance = new FoldFinder();
    }

    public List<SectionPosition> Find(string code, List<SectionDelimiter> delimiters, int start = 0,
        int end = -1)
    {
        List<SectionPosition> positions = new List<SectionPosition>();
        Stack<SectionStackItem> stack = new Stack<SectionStackItem>();

        int regexGroupIndex;
        bool isStartToken;
        SectionDelimiter matchedDelimiter;
        SectionStackItem currentItem;

        Regex scanner = RegexifyDelimiters(delimiters);

        foreach (Match match in scanner.Matches(code, start))
        {
            // the pattern for every group is that 0 corresponds to SectionDelimter, 1 corresponds to Start
            // and 2, corresponds to End.
            regexGroupIndex = 
                match.Groups.Cast<Group>().Select((g, i) => new {
                    Success = g.Success,
                    Index = i
                })
                .Where(r => r.Success && r.Index > 0).First().Index;

            matchedDelimiter = delimiters[(regexGroupIndex - 1) / 3];
            isStartToken = match.Groups[regexGroupIndex + 1].Success;

            if (isStartToken)
            {
                stack.Push(new SectionStackItem()
                {
                    Delimter = matchedDelimiter,
                    Position = new SectionPosition() { Start = match.Index }
                });
            }
            else
            {
                currentItem = stack.Pop();
                if (currentItem.Delimter == matchedDelimiter)
                {
                    currentItem.Position.End = match.Index + match.Length;
                    positions.Add(currentItem.Position);

                    // if searching for an end, and we've passed it, and the stack is empty then quit.
                    if (end > -1 && currentItem.Position.End >= end && stack.Count == 0) break;
                }
                else
                {
                    throw new Exception(string.Format("Invalid Ending Token at {0}", match.Index)); 
                }
            }
        }

        if (stack.Count > 0) throw new Exception("Not enough closing symbols.");

        return positions;
    }

    public Regex RegexifyDelimiters(List<SectionDelimiter> delimiters)
    {
        return new Regex(
            string.Join("|", delimiters.Select(d =>
                string.Format("(({0})|({1}))", d.Start, d.End))));
    }

}

public class SectionStackItem
{
    public SectionPosition Position;
    public SectionDelimiter Delimter;
}

public class SectionPosition
{
    public int Start;
    public int End;
}

public class SectionDelimiter
{
    public string Start;
    public string End;
}

示例查找

下面的示例匹配由{,}，[,]分隔的折叠，并且在符号后面直到;。我没有看到太多的IDE折叠为每一行，但它可能很方便很长的代码片段，如LINQ查询。

var sectionPositions = 
    FoldFinder.Instance.Find("abc { def { qrt; ghi [ abc ] } qrt }", new List<SectionDelimiter>(
        new SectionDelimiter[3] {
            new SectionDelimiter() { Start = "\\{", End = "\\}" },
            new SectionDelimiter() { Start = "\\[", End = "\\]" },
            new SectionDelimiter() { Start = "(?<=\\[|\\{|;|^)[^[{;]*(?=;)", End = ";" },
        }));

RichTextBox中的代码折叠

1 个答案:

折叠查找器

示例查找