正则表达式 - 捕获重复组 [英] Regex - Capturing a Repeated Group

问题描述

好吧，我读过的教程和炒我的头太多要能看清楚了。

Alright, I've read the tutorials and scrambled my head too much to be able to see clearly now.

我试图捕捉参数和函数签名的类型信息。因此，考虑签名是这样的：

I'm trying to capture parameters and their type info from a function signature. So given a signature like this:

function(/*string*/a,b,c)

我想要得到的部分是这样的：

I want to get the parts like this:

type: string
param:a
param:b
param:c

这是好太多：

type: string
param:a
type: null (or whitespace)
param:b
type: null (or whitespace)
param:c

于是我想出了这个正则表达式这是做重复采集的常见错误（我已经明确捕捉开启）：

So I came up with this regex which is doing the common mistake of repeating the capture (I've explicit capture turned on):

function\(((\/\*(?<type>[a-zA-Z]+)\*\/)?(?<param>[0-9a-zA-Z_$]+),?)*\)

但问题是，我不能纠正错误。 :(请帮帮忙！

Problem is, I can't correct the mistake. :(. Please help!

推荐答案

通常情况下，你需要两个步骤获得的所有数据。
首先，匹配/验证整个功能：

Generally, you'd need two steps to get all data.
First, match/validate the whole function:

function\((?<parameters>((\/\*[a-zA-Z]+\*\/)?[0-9a-zA-Z_$]+,?)*)\)

请注意，现在你有一个参数组所有参数。你可以搭配一些样式再次得到所有的参数匹配，或在这种情况下，拆分对，。

Note that now you have a parameters group with all parameters. You can match some of the pattern again to get all matches of parameters, or in this case, split on ,.

如果你使用的.Net，不管怎样，你很幸运。净保留每个组的所有捕获的全部记录，这样你就可以使用集合：

If you're using .Net, by any chance, you're in luck. .Net keeps full record of all captures of each group, so you can use the collection:

match.Groups["param"].Captures

一些注意事项：

Some notes:

• 如果你想捕捉多个类型，您一定要空场比赛，这样你就可以很容易地结合比赛（虽然你可以进行排序，但1：1的捕捉整洁）。在这种情况下，你想要的可选组的在的捕获的组：<？code>（小于型＆GT;（\ / \ * [A-ZA-Z] + \ * \ / ）？）
• 您不必逃避斜线净模式 - / 有没有什么特别的意义有（C＃/。网络不具有正则表达式的分隔符）

• If you do want to capture more than one type, you definitely want empty matches, so you can easily combine the matches (though you can sort, but a 1-to-1 capture is neater). In that case, you want the optional group inside your captured group: (?<type>(\/\*[a-zA-Z]+\*\/)?)
• You don't have to escape slashes in .Net patterns - / has no special meaning there (C#/.Net doesn't have regex delimiters).

下面是一个使用捕获的一个例子。此外，主要的一点是保持在关系类型和参数：要捕捉空的类型，所以你不'T失去计数。
图案：

Here's an example of using the captures. Again, the main point is maintaining the relation between type and param: you want to capture empty types, so you don't lose count.
Pattern:

function
\(
(?:
    (?:
        /\*(?<type>[a-zA-Z]+)\*/    # type within /* */
        |                           # or
        (?<type>)                   # capture an empty type.
    )
    (?<param>
        [0-9a-zA-Z_$]+
    )
    (?:,|(?=\s*\)))     # mandatory comma, unless before the last ')'
)*
\)

code：

Code:

Match match = Regex.Match(s, pattern, RegexOptions.IgnorePatternWhitespace);
CaptureCollection types = match.Groups["type"].Captures;
CaptureCollection parameters = match.Groups["param"].Captures;
for (int i = 0; i < parameters.Count; i++)
{
    string parameter = parameters[i].Value;
    string type = types[i].Value;
    if (String.IsNullOrEmpty(type))
        type = "NO TYPE";
    Console.WriteLine("Parameter: {0}, Type: {1}", parameter, type);
}

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