如何在Groovy的/pattern/语法中转义Unicode转义 [英] How to escape Unicode escapes in Groovy's /pattern/ syntax

问题描述

以下Groovy命令说明了我的问题.

The following Groovy commands illustrate my problem.

首先，这有效(

First of all, this works (as seen on lotrepls.appspot.com) as expected (note that \u0061 is 'a').

>>> print "a".matches(/\u0061/)

true

现在，我们要使用Unicode转义 \ u000A 匹配 \ n .以下使用"pattern" 作为字符串，其行为符合预期:

Now let's say that we want to match \n, using the Unicode escape \u000A. The following, using "pattern" as a string, behaves as expected:

>>> print "\n".matches("\u000A");

Interpreter exception: com.google.lotrepls.shared.InterpreterException:
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed,
Script1.groovy: 1: expecting anything but ''\n''; got it anyway
@ line 1, column 21. 1 error

这是可以预期的，因为至少在Java中，Unicode转义会及早处理( JLS 3.3 )，因此:

This is expected because in Java at least, Unicode escapes are processed early (JLS 3.3), so:

print "\n".matches("\u000A")

确实与:

print "\n".matches("
")

解决方法是对Unicode转义进行转义，然后让正则表达式引擎对其进行处理，如下所示:

The fix is to escape the Unicode escape, and let the regex engine process it, as follows:

>>> print "\n".matches("\\u000A")

true

现在这是有问题的部分:如何使它与Groovy /pattern/语法一起使用，而不是使用字符串文字?

Now here's the question part: how can we get this to work with the Groovy /pattern/ syntax instead of using string literal?

以下是一些失败的尝试:

Here are some failed attempts:

>>> print "\n".matches(/\u000A/)

Interpreter exception: com.google.lotrepls.shared.InterpreterException:
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed,
Script1.groovy: 1: expecting EOF, found '(' @ line 1, column 19.
1 error

>>> print "\n".matches(/\\u000A/)

false

>>> print "\\u000A".matches(/\\u000A/);

true

推荐答案

〜"[[\ u0000- \ u0008 \ u000B \ u000C \ u000E- \ u001F \ u007F- \ u009F]"

~"[\u0000-\u0008\u000B\u000C\u000E-\u001F\u007F-\u009F]"

似乎可以正常工作.根据我所看到的文档，斜线字符串不需要双反斜杠，所以我不知道为什么编译器对它们不满意.

Appears to be working as it should. According to the docs I've seen, the double backslashes shouldn't be required with a slashy string, so I don't know why the compiler's not happy with them.

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