有没有办法在vim regex中进行负前瞻? [英] Is there a way to do negative lookahead in vim regex?

问题描述

在Vim中，有没有一种方法可以搜索与说abc相匹配的行，但以后在该行中也不包含xyz?因此，以下几行将匹配:

In Vim, is there a way to search for lines that match say abc but do not also contain xyz later on the line? So the following lines would match:

The abc is the best
The first three letters are abc

，以下内容不匹配:

The abc is the best but xyz is cheaper
The first three letters are abc and the last are xyz

我了解如下语法:

/abc\(xyz\)\@!

，但这只会避免匹配abcxyz，如果两者之间没有任何东西(例如abc-xyz)，则不会.使用

but that only avoids matching abcxyz and not if there is anything in between, such as abc-xyz. Using

/abc.*\(xyz\)\@!

也不起作用，因为该行后面的许多位置xyz不匹配.

also does not work because there are many positions later in the line where xyz is not matched.

(我应该注意，在命令行上我会做类似grep abc <infile | grep -v xyz的操作，但是我想在Vim中以交互方式执行上述操作.)

(I should note that on the command line I would do something like grep abc <infile | grep -v xyz but I would like to do the above interactively in Vim.)

推荐答案

您的尝试非常接近；您需要拉动.* ，以允许匹配和断言的以后的不匹配之间的任意距离进入否定的预测:

Your attempt was pretty close; you need to pull the .* that allows an arbitrary distance between the match and the asserted later non-match into the negative look-ahead:

/abc\(.*xyz\)\@!

我猜这是可行的，因为尝试对.*的所有可能匹配都进行不匹配，并且只有当所有分支都用完后，\@!才声明为已实现.

I guess this works because the non-match is attempted for all possible matches of .*, and only when all branches have been exhausted is the \@! declared as fulfilled.

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