2

我无法处理正则表达式来将参数与函数分开。该函数以下列方式接受参数:

FunctionName(arg1;arg2;...;argn)

现在要使我的其余代码工作,我需要执行以下操作 - 将每个参数放在 () 中:

FunctionName((arg1);(arg2);(arg3))

问题是 arg 可以是任何东西——数字、运算符、其他函数

该解决方案的测试代码为:

正则表达式之前的函数:

Function1((a1^5-4)/2;1/sin(a2);a3;a4)+Function2(a1;a2;1/a3)

在我需要得到这样的东西之后:

Function1(((a1^5-4)/2);(1/sin(a2));(a3);(a4))+Function2((a1);(a2);(1/a3))
4

4 回答 4

1

除非我遗漏了一些东西,否则它不是像替换和包围整个东西一样;简单);(( )

于 2012-10-13T04:49:08.953 回答
1

这与嵌套函数的潜力相去甚远,Regex再加上这是一种正在修改的结构化语言,因此词法分析器/解析器方案更合适。

这是处理这种性质的事物的系统示例

首先,我们定义一些可以位于输入中的东西(要修改的表达式)

public interface ISourcePart
{
    /// <summary>
    /// Gets the string representation of the kind of thing we're working with
    /// </summary>
    string Kind { get; }

    /// <summary>
    /// Gets the position this information is found at in the original source
    /// </summary>
    int Position { get; }

    /// <summary>
    /// Gets a representation of this data as Token objects
    /// </summary>
    /// <returns>An array of Token objects representing the data</returns>
    Token[] AsTokens();
}

接下来,我们将为房屋标记(源文本的可识别部分)定义一个构造

public class Token : ISourcePart
{
    public int Position { get; set; }

    public Token[] AsTokens()
    {
        return new[] {this};
    }

    public string Kind { get; set; }

    /// <summary>
    /// Gets or sets the value of the token
    /// </summary>
    public string Value { get; set; }

    /// <summary>
    /// Creates a new Token
    /// </summary>
    /// <param name="kind">The kind (name) of the token</param>
    /// <param name="match">The Match the token is to be generated from</param>
    /// <param name="index">The offset from the beginning of the file the index of the match is relative to</param>
    /// <returns>The newly created token</returns>
    public static Token Create(string kind, Match match, int index)
    {
        return new Token
        {
            Position = match.Index + index,
            Kind = kind,
            Value = match.Value
        };
    }

    /// <summary>
    /// Creates a new Token
    /// </summary>
    /// <param name="kind">The kind (name) of the token</param>
    /// <param name="value">The value to assign to the token</param>
    /// <param name="position">The absolute position in the source file the value is located at</param>
    /// <returns>The newly created token</returns>
    public static Token Create(string kind, string value, int position)
    {
        return new Token
        {
            Kind = kind,
            Value = value,
            Position = position
        };
    }
}

在此示例中,我们将使用Regexes 来查找我们的令牌(以下 - 摘自我的演示项目中的 Program.cs)。

/// <summary>
/// Breaks an input string into recognizable tokens
/// </summary>
/// <param name="source">The input string to break up</param>
/// <returns>The set of tokens located within the string</returns>
static IEnumerable<Token> Tokenize(string source)
{
    var tokens = new List<Token>();
    var sourceParts = new[] { new KeyValuePair<string, int>(source, 0) };

    tokens.AddRange(Tokenize(OpenParen, "\\(", ref sourceParts));
    tokens.AddRange(Tokenize(CloseParen, "\\)", ref sourceParts));
    tokens.AddRange(Tokenize(Semi, ";", ref sourceParts));
    tokens.AddRange(Tokenize(Operator, "[\\^\\\\*\\+\\-/]", ref sourceParts));
    tokens.AddRange(Tokenize(Literal, "\\w+", ref sourceParts));

    return tokens.OrderBy(x => x.Position);
}

如您所见,我已经为左括号和右括号、分号、基本数学运算符以及字母和数字定义了模式。

Tokenize方法定义如下(再次来自我的演示项目中的 Program.cs)

/// <summary>
/// Performs tokenization of a collection of non-tokenized data parts with a specific pattern
/// </summary>
/// <param name="tokenKind">The name to give the located tokens</param>
/// <param name="pattern">The pattern to use to match the tokens</param>
/// <param name="untokenizedParts">The portions of the input that have yet to be tokenized (organized as text vs. position in source)</param>
/// <returns>The set of tokens matching the given pattern located in the untokenized portions of the input, <paramref name="untokenizedParts"/> is updated as a result of this call</returns>
static IEnumerable<Token> Tokenize(string tokenKind, string pattern, ref KeyValuePair<string, int>[] untokenizedParts)
{
    //Do a bit of setup
    var resultParts = new List<KeyValuePair<string, int>>();
    var resultTokens = new List<Token>();
    var regex = new Regex(pattern);

    //Look through all of our currently untokenized data
    foreach (var part in untokenizedParts)
    {
        //Find all of our available matches
        var matches = regex.Matches(part.Key).OfType<Match>().ToList();

        //If we don't have any, keep the data as untokenized and move to the next chunk
        if (matches.Count == 0)
        {
            resultParts.Add(part);
            continue;
        }

        //Store the untokenized data in a working copy and save the absolute index it reported itself at in the source file
        var workingPart = part.Key;
        var index = part.Value;

        //Look through each of the matches that were found within this untokenized segment
        foreach (var match in matches)
        {
            //Calculate the effective start of the match within the working copy of the data
            var effectiveStart = match.Index - (part.Key.Length - workingPart.Length);
            resultTokens.Add(Token.Create(tokenKind, match, part.Value));

            //If we didn't match at the beginning, save off the first portion to the set of untokenized data we'll give back
            if (effectiveStart > 0)
            {
                var value = workingPart.Substring(0, effectiveStart);
                resultParts.Add(new KeyValuePair<string, int>(value, index));
            }

            //Get rid of the portion of the working copy we've already used
            if (match.Index + match.Length < part.Key.Length)
            {
                workingPart = workingPart.Substring(effectiveStart + match.Length);
            }
            else
            {
                workingPart = string.Empty;
            }

            //Update the current absolute index in the source file we're reporting to be at
            index += effectiveStart + match.Length;
        }

        //If we've got remaining data in the working copy, add it back to the untokenized data
        if (!string.IsNullOrEmpty(workingPart))
        {
            resultParts.Add(new KeyValuePair<string, int>(workingPart, index));
        }
    }

    //Update the untokenized data to contain what we couldn't process with this pattern
    untokenizedParts = resultParts.ToArray();
    //Return the tokens we were able to extract
    return resultTokens;
}

现在我们已经有了处理标记化数据的方法和类型,我们需要能够识别更大含义的片段,比如对简单函数(如sin(x))、复杂函数(如Function1(a1;a2;a3))、基本数学运算(如+, -, *, 等)等等。我们将制作一个简单的解析器来处理它;首先,我们将为解析节点定义匹配条件。

public class ParseNodeDefinition
{
    /// <summary>
    /// The set of parse node definitions that could be transitioned to from this one
    /// </summary>
    private readonly IList<ParseNodeDefinition> _nextNodeOptions;

    /// <summary>
    /// Creates a new ParseNodeDefinition
    /// </summary>
    private ParseNodeDefinition()
    {
        _nextNodeOptions = new List<ParseNodeDefinition>();
    }

    /// <summary>
    /// Gets whether or not this definition is an acceptable ending point for the parse tree
    /// </summary>
    public bool IsValidEnd { get; private set; }

    /// <summary>
    /// Gets the name an item must have for it to be matched by this definition
    /// </summary>
    public string MatchItemsNamed { get; private set; }

    /// <summary>
    /// Gets the set of parse node definitions that could be transitioned to from this one
    /// </summary>
    public IEnumerable<ParseNodeDefinition> NextNodeOptions
    {
        get { return _nextNodeOptions; }
    }

    /// <summary>
    /// Gets or sets the tag that will be associated with the data if matched
    /// </summary>
    public string Tag { get; set; }

    /// <summary>
    /// Creates a new ParseNodeDefinition matching items with the specified name/kind.
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <param name="tag">The tag to associate with matched items</param>
    /// <param name="isValidEnd">Whether or not the element is a valid end to the parse tree</param>
    /// <returns>A ParseNodeDefinition capable of matching items of the given name</returns>
    public static ParseNodeDefinition Create(string matchItemsNamed, string tag, bool isValidEnd)
    {
        return new ParseNodeDefinition { MatchItemsNamed = matchItemsNamed, Tag = tag, IsValidEnd = isValidEnd };
    }

    public ParseNodeDefinition AddOption(string matchItemsNamed)
    {
        return AddOption(matchItemsNamed, string.Empty, false);
    }

    public ParseNodeDefinition AddOption(string matchItemsNamed, string tag)
    {
        return AddOption(matchItemsNamed, tag, false);
    }

    /// <summary>
    /// Adds an option for a named node to follow this one in the parse tree the node is a part of
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <param name="tag">The tag to associate with matched items</param>
    /// <param name="isValidEnd">Whether or not the element is a valid end to the parse tree</param>
    /// <returns>The ParseNodeDefinition that has been added</returns>
    public ParseNodeDefinition AddOption(string matchItemsNamed, string tag, bool isValidEnd)
    {
        var node = Create(matchItemsNamed, tag, isValidEnd);
        _nextNodeOptions.Add(node);
        return node;
    }

    public ParseNodeDefinition AddOption(string matchItemsNamed, bool isValidEnd)
    {
        return AddOption(matchItemsNamed, string.Empty, isValidEnd);
    }

    /// <summary>
    /// Links the given node as an option for a state to follow this one in the parse tree this node is a part of
    /// </summary>
    /// <param name="next">The node to add as an option</param>
    public void LinkTo(ParseNodeDefinition next)
    {
        _nextNodeOptions.Add(next);
    }
}

这将让我们按名称匹配单个元素(无论是ParseTree稍后定义的)还是 aToken因为它们都实现了ISourcePart接口。接下来我们将创建一个ParseTreeDefinition允许我们指定ParseNodeDefinitions匹配序列的。

public class ParseTreeDefinition
{
    /// <summary>
    /// The set of parse node definitions that constitute an initial match to the parse tree
    /// </summary>
    private readonly IList<ParseNodeDefinition> _initialNodeOptions;

    /// <summary>
    /// Creates a new ParseTreeDefinition
    /// </summary>
    /// <param name="name">The name to give to parse trees generated from full matches</param>
    public ParseTreeDefinition(string name)
    {
        _initialNodeOptions = new List<ParseNodeDefinition>();
        Name = name;
    }

    /// <summary>
    /// Gets the set of parse node definitions that constitute an initial match to the parse tree
    /// </summary>
    public IEnumerable<ParseNodeDefinition> InitialNodeOptions { get { return _initialNodeOptions; } }

    /// <summary>
    /// Gets the name of the ParseTreeDefinition
    /// </summary>
    public string Name { get; private set; }

    /// <summary>
    /// Adds an option for a named node to follow this one in the parse tree the node is a part of
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <returns>The ParseNodeDefinition that has been added</returns>
    public ParseNodeDefinition AddOption(string matchItemsNamed)
    {
        return AddOption(matchItemsNamed, string.Empty, false);
    }

    /// <summary>
    /// Adds an option for a named node to follow this one in the parse tree the node is a part of
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <param name="tag">The tag to associate with matched items</param>
    /// <returns>The ParseNodeDefinition that has been added</returns>
    public ParseNodeDefinition AddOption(string matchItemsNamed, string tag)
    {
        return AddOption(matchItemsNamed, tag, false);
    }

    /// <summary>
    /// Adds an option for a named node to follow this one in the parse tree the node is a part of
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <param name="tag">The tag to associate with matched items</param>
    /// <param name="isValidEnd">Whether or not the element is a valid end to the parse tree</param>
    /// <returns>The ParseNodeDefinition that has been added</returns>
    public ParseNodeDefinition AddOption(string matchItemsNamed, string tag, bool isValidEnd)
    {
        var node = ParseNodeDefinition.Create(matchItemsNamed, tag, isValidEnd);
        _initialNodeOptions.Add(node);
        return node;
    }

    /// <summary>
    /// Adds an option for a named node to follow this one in the parse tree the node is a part of
    /// </summary>
    /// <param name="matchItemsNamed">The name of the item to be matched</param>
    /// <param name="isValidEnd">Whether or not the element is a valid end to the parse tree</param>
    /// <returns>The ParseNodeDefinition that has been added</returns>
    public ParseNodeDefinition AddOption(string matchItemsNamed, bool isValidEnd)
    {
        return AddOption(matchItemsNamed, string.Empty, isValidEnd);
    }

    /// <summary>
    /// Attempts to follow a particular branch in the parse tree from a given starting point in a set of source parts
    /// </summary>
    /// <param name="parts">The set of source parts to attempt to match in</param>
    /// <param name="startIndex">The position to start the matching attempt at</param>
    /// <param name="required">The definition that must be matched for the branch to be followed</param>
    /// <param name="nodes">The set of nodes that have been matched so far</param>
    /// <returns>true if the branch was followed to completion, false otherwise</returns>
    private static bool FollowBranch(IList<ISourcePart> parts, int startIndex, ParseNodeDefinition required, ICollection<ParseNode> nodes)
    {
        if (parts[startIndex].Kind != required.MatchItemsNamed)
        {
            return false;
        }

        nodes.Add(new ParseNode(parts[startIndex], required.Tag));

        return parts.Count > (startIndex + 1) && required.NextNodeOptions.Any(x => FollowBranch(parts, startIndex + 1, x, nodes)) || required.IsValidEnd;
    }

    /// <summary>
    /// Attempt to match the parse tree definition against a set of source parts
    /// </summary>
    /// <param name="parts">The source parts to match against</param>
    /// <returns>true if the parse tree was matched, false otherwise. parts is updated by this method to consolidate matched nodes into a ParseTree</returns>
    public bool Parse(ref IList<ISourcePart> parts)
    {
        var partsCopy = parts.ToList();

        for (var i = 0; i < parts.Count; ++i)
        {
            var tree = new List<ParseNode>();

            if (InitialNodeOptions.Any(x => FollowBranch(partsCopy, i, x, tree)))
            {
                partsCopy.RemoveRange(i, tree.Count);
                partsCopy.Insert(i, new ParseTree(Name, tree.ToArray(), tree[0].Position));
                parts = partsCopy;
                return true;
            }
        }

        return false;
    }
}

当然,如果没有一些地方来存储我们迄今为止定义的匹配器的结果,这些对我们没有多大好处,所以让我们定义ParseTreeaParseNode是一个ParseTree简单的ParseNode对象集合,它ParseNode是围绕 aParseTreeToken(或更多)的包装器一般任何ISourcePart)。

public class ParseTree : ISourcePart
{
    /// <summary>
    /// Creates a new ParseTree
    /// </summary>
    /// <param name="kind">The kind (name) of tree this is</param>
    /// <param name="nodes">The nodes the tree matches</param>
    /// <param name="position">The position in the source file this tree is located at</param>
    public ParseTree(string kind, IEnumerable<ISourcePart> nodes, int position)
    {
        Kind = kind;
        ParseNodes = nodes.ToList();
        Position = position;
    }

    public string Kind { get; private set; }

    public int Position { get; private set; }

    /// <summary>
    /// Gets the nodes that make up this parse tree
    /// </summary>
    public IList<ISourcePart> ParseNodes { get; internal set; }

    public Token[] AsTokens()
    {
        return ParseNodes.SelectMany(x => x.AsTokens()).ToArray();
    }
}

public class ParseNode : ISourcePart
{
    /// <summary>
    /// Creates a new ParseNode
    /// </summary>
    /// <param name="sourcePart">The data that was matched to create this node</param>
    /// <param name="tag">The tag data (if any) associated with the node</param>
    public ParseNode(ISourcePart sourcePart, string tag)
    {
        SourcePart = sourcePart;
        Tag = tag;
    }

    public string Kind { get { return SourcePart.Kind; } }

    /// <summary>
    /// Gets the tag associated with the matched data
    /// </summary>
    public string Tag { get; private set; }

    /// <summary>
    /// Gets the data that was matched to create this node
    /// </summary>
    public ISourcePart SourcePart { get; private set; }

    public int Position { get { return SourcePart.Position; } }

    public Token[] AsTokens()
    {
        return SourcePart.AsTokens();
    }
}

这就是我们需要的构造,所以我们将开始配置我们的解析树定义。从这里开始的代码来自我演示中的 Program.cs。

正如您可能已经注意到,在上面关于为每个标记声明模式的块中,有一些值被引用但未定义,在这里它们是。

private const string CloseParen = "CloseParen";
private const string ComplexFunctionCall = "ComplexFunctionCall";
private const string FunctionCallStart = "FunctionCallStart";
private const string Literal = "Literal";
private const string OpenParen = "OpenParen";
private const string Operator = "Operator";
private const string ParenthesisRequiredElement = "ParenthesisRequiredElement";
private const string ParenthesizedItem = "ParenthesizedItem";
private const string Semi = "Semi";
private const string SimpleFunctionCall = "SimpleFunctionCall";

让我们首先定义一个匹配字面量 ( \w+pattern) 的模式,后跟开括号;我们将使用它来匹配诸如sin(or之类的东西Function1(

static ParseTreeDefinition CreateFunctionCallStartTree()
{
    var tree = new ParseTreeDefinition(FunctionCallStart);
    var name = tree.AddOption(Literal);
    name.AddOption(OpenParen, true);
    return tree;
}

真的不是很多,设置一棵树,为第一个匹配的内容添加一个选项作为文字,添加一个作为左括号匹配的下一个选项,并说它可以结束解析树。现在对于一个稍微复杂一点的二元数学运算(想不出任何需要包含的一元运算)

static ParseTreeDefinition CreateBinaryOperationResultTree()
{
    var tree = new ParseTreeDefinition(Literal);
    var parenthesizedItem = tree.AddOption(ParenthesizedItem);
    var literal = tree.AddOption(Literal);
    var simpleCall = tree.AddOption(SimpleFunctionCall);
    var complexCall = tree.AddOption(ComplexFunctionCall);

    var @operator = parenthesizedItem.AddOption(Operator);
    literal.LinkTo(@operator);
    simpleCall.LinkTo(@operator);
    complexCall.LinkTo(@operator);

    @operator.AddOption(ParenthesizedItem, true);
    @operator.AddOption(Literal, true);
    @operator.AddOption(SimpleFunctionCall, true);
    @operator.AddOption(ComplexFunctionCall, true);
    return tree;
}

这里我们说解析树可以以带括号的项目(like (1/2))、文字(like a5or 3)、简单的调用(like sin(4))或复杂的调用(likeFunction1(a1;a2;a3))。本质上,我们刚刚定义了左侧操作数的选项。接下来,我们说带括号的项目后面必须跟一个运算符(从开头声明的模式中的数学运算符之一),为了方便起见,我们将说左侧操作数的所有其他选项可以进展到相同的状态(有操作员)。接下来,操作员也必须有右手边,所以我们给它一组重复的选项以继续前进。请注意,它们与左侧操作数的定义不同,它们设置了能够终止解析树的标志。请注意,解析树被命名为 Literal 以避免必须指定另一种元素来匹配所有地方。接下来,带括号的项目:

static ParseTreeDefinition CreateParenthesizedItemTree()
{
    var tree = new ParseTreeDefinition(ParenthesizedItem);
    var openParen = tree.AddOption(OpenParen);

    var nestedSimpleCall = openParen.AddOption(SimpleFunctionCall);
    var nestedComplexCall = openParen.AddOption(ComplexFunctionCall);
    var arg = openParen.AddOption(Literal);
    var parenthesizedItem = openParen.AddOption(ParenthesizedItem);

    var closeParen = nestedSimpleCall.AddOption(CloseParen, true);
    arg.LinkTo(closeParen);
    parenthesizedItem.LinkTo(closeParen);
    nestedComplexCall.LinkTo(closeParen);
    return tree;
}

这个很好,很容易,从一个括号开始,几乎任何东西都跟着它,然后用另一个括号来结束它。简单的调用(如sin(x)

static ParseTreeDefinition CreateSimpleFunctionCallTree()
{
    var tree = new ParseTreeDefinition(SimpleFunctionCall);
    var openParen = tree.AddOption(FunctionCallStart);

    var nestedItem = openParen.AddOption(ParenthesizedItem);
    var nestedSimpleCall = openParen.AddOption(SimpleFunctionCall);
    var nestedComplexCall = openParen.AddOption(ComplexFunctionCall);
    var arg = openParen.AddOption(Literal);
    var parenthesizedItem = openParen.AddOption(ParenthesizedItem);

    var closeParen = nestedSimpleCall.AddOption(CloseParen, true);
    arg.LinkTo(closeParen);
    nestedItem.LinkTo(closeParen);
    parenthesizedItem.LinkTo(closeParen);
    nestedComplexCall.LinkTo(closeParen);

    return tree;
}

复杂的调用(如Function1(a1;a2;a3)

static ParseTreeDefinition CreateComplexFunctionCallTree()
{
    var tree = new ParseTreeDefinition(ComplexFunctionCall);
    var openParen = tree.AddOption(FunctionCallStart);

    var arg = openParen.AddOption(Literal, ParenthesisRequiredElement);
    var simpleCall = openParen.AddOption(SimpleFunctionCall, ParenthesisRequiredElement);
    var complexCall = openParen.AddOption(ComplexFunctionCall, ParenthesisRequiredElement);
    var nested = openParen.AddOption(ParenthesizedItem);

    var semi = arg.AddOption(Semi);
    simpleCall.LinkTo(semi);
    complexCall.LinkTo(semi);
    nested.LinkTo(semi);

    var arg2 = semi.AddOption(Literal, ParenthesisRequiredElement);
    var simpleCall2 = semi.AddOption(SimpleFunctionCall, ParenthesisRequiredElement);
    var complexCall2 = semi.AddOption(ComplexFunctionCall, ParenthesisRequiredElement);
    var nested2 = semi.AddOption(ParenthesizedItem);
    arg2.LinkTo(semi);
    simpleCall2.LinkTo(semi);
    complexCall2.LinkTo(semi);
    nested2.LinkTo(semi);

    var closeParen = arg2.AddOption(CloseParen, true);
    arg2.LinkTo(closeParen);
    simpleCall2.LinkTo(closeParen);
    complexCall2.LinkTo(closeParen);
    return tree;
}

这就是我们需要的所有树,所以让我们看看运行这一切的代码

static void Main()
{
    //The input string
    const string input = @"Function1((a1^5-4)/2;1/sin(a2);a3;a4)+Function2(a1;a2;1/a3)";
    //Locate the recognizable tokens within the source
    IList<ISourcePart> tokens = Tokenize(input).Cast<ISourcePart>().ToList();
    //Create the parse trees we'll need to be able to recognize the different parts of the input
    var functionCallStartTree = CreateFunctionCallStartTree();
    var parenthethesizedItemTree = CreateParenthesizedItemTree();
    var simpleFunctionCallTree = CreateSimpleFunctionCallTree();
    var complexFunctionCallTree = CreateComplexFunctionCallTree();
    var binaryOpTree = CreateBinaryOperationResultTree();

    //Parse until we can't parse anymore
    while (functionCallStartTree.Parse(ref tokens) || binaryOpTree.Parse(ref tokens) || parenthethesizedItemTree.Parse(ref tokens) || simpleFunctionCallTree.Parse(ref tokens) || complexFunctionCallTree.Parse(ref tokens))
    { }

    //Run our post processing to fix the parenthesis in the input
    FixParenthesis(ref tokens);

    //Collapse our parse tree(s) back to a string
    var values = tokens.OrderBy(x => x.Position).SelectMany(x => x.AsTokens()).Select(x => x.Value);

    //Print out our results and wait
    Console.WriteLine(string.Join(string.Empty, values));
    Console.ReadLine();
}

我们唯一需要定义的是如何实际包装“复杂”调用的参数列表中的元素。这是由FixParenthesis方法处理的。

private static void FixParenthesis(ref IList<ISourcePart> items)
{
    //Iterate through the set we're examining
    for (var i = 0; i < items.Count; ++i)
    {
        var parseNode = items[i] as ParseNode;

        //If we've got a parse node...
        if (parseNode != null)
        {
            var nodeTree = parseNode.SourcePart as ParseTree;
            //If the parse node represents a parse tree...
            if (nodeTree != null)
            {
                //Fix parenthesis within the tree
                var nodes = nodeTree.ParseNodes;
                FixParenthesis(ref nodes);
                nodeTree.ParseNodes = nodes;
            }

            //If this parse node required parenthesis, replace the subtree and add them
            if (parseNode.Tag == ParenthesisRequiredElement)
            {
                var nodeContents = parseNode.AsTokens();
                var combined = string.Join(string.Empty, nodeContents.OrderBy(x => x.Position).Select(x => x.Value));
                items[i] = Token.Create(parseNode.Kind, string.Format("({0})", combined), parseNode.Position);
            }

            continue;
        }

        var parseTree = items[i] as ParseTree;

        //If we've got a parse tree...
        if (parseTree != null)
        {
            //Fix parenthesis within the tree
            var nodes = parseTree.ParseNodes;
            FixParenthesis(ref nodes);
            parseTree.ParseNodes = nodes;
        }
    }
}

无论如何,我希望这有助于或至少提供了一个有趣的消遣。

于 2012-10-14T06:15:36.507 回答
1

使用Regex

(?:([^;()]+);?)+

LINQ

string result = "FunctionName(" +
                String.Join(";",
                            from Capture capture in
                                Regex.Matches(inputString, @"FunctionName\((?:([^;()]+);?)+\)")[0].Groups[1].
                                Captures
                            select "(" + capture.Value + ")") + ")";
于 2012-10-13T04:55:45.780 回答
0

我可能设法处理它(现在正在测试)。原来是5阶段操作。假设 '{' 和 ';' 不能发生在我这样做的功能中:

        sBuffer = Regex.Replace(sBuffer, @"(?<sep>[;])", "};{");
        sBuffer = Regex.Replace(sBuffer, @"([(])(?<arg>.+?)[}]", "({${arg}}");
        sBuffer = Regex.Replace(sBuffer, @"([;])(?<arg>.+?)([)]){1}", ";${arg}})");
        sBuffer = Regex.Replace(sBuffer, @"{", "(");
        sBuffer = Regex.Replace(sBuffer, @"}", ")");

0。 function1((a1^5-4)/2;1/sin(a2);a3;a4)+function2(a1;a2;1/a3)'

1.第一行替换;和 };{

function1((a1^5-4)/2};{1/sin(a2)};{a3};{a4)+function2(a1};{a2};{1/a3)

2.对于第一个参数 - 在包含“)”的(或(非预期)参数之后)替换(arg};with({arg}:

function1({(a1^5-4)/2};{1/sin({a2)};{a3};{a4)+function2({a1};{a2};{1/a3)

3. 函数的 and 相同:{arg) 和 {arg}:

function1({(a1^5-4)/2};{1/sin({a2})};{a3};{a4})+function2({a1};{a2};{1/a3})

4.5. 将 '{' 和 '}' 替换为 '(' ')':

function1(((a1^5-4)/2);(1/sin((a2)));(a3);(a4))+function2((a1);(a2);(1/a3))

我们有一些额外的 () 特别是当参数本身被 '(' ')' (嵌套函数)包围时,但它并没有改变,因为代码随后通过反向波兰表示法进行

这是我的第一个 regexp 代码(几天前我发现了 rgexp - 我是初学者)。我希望它满足所有情况(至少那些可能出现在 excel 公式中的情况)

于 2012-10-13T09:40:54.940 回答