RegEx修改Backreference的值

有没有办法修改反向引用的值

例如： 在下文中

"this is a test"

单词“test”应该被提取出来，并通过反引用插入到另一个文本中

正则表达式：

(test)

替换：

"this is another \1"

到目前为止效果不错。但现在的问题是，是否可以在插入之前修改反向引用。类似于将单词test转换为大写

我想它可能看起来像：

"this is another \to_upper\1"

---

标准中有什么规定吗？有什么标准吗？正则表达式？

许多javascript、python等实现都允许您指定一个函数作为替换参数。函数通常将整个匹配字符串、其在输入字符串中的位置以及捕获的组作为参数。此函数返回的字符串用作替换文本

下面是使用JavaScript的方法：replace函数将整个匹配的子字符串作为第一个参数，捕获的组的值作为下一个n个参数，然后是原始输入字符串中匹配字符串的索引和整个输入字符串

var s = "this is a test. and this is another one.";
console.log("replacing");
r = s.replace(/(this is) ([^.]+)/g, function(match, first, second, pos, input) {
  console.log("matched   :" + match);
  console.log("1st group :" + first);
  console.log("2nd group :" + second);
  console.log("position  :" + pos);
  console.log("input     :" + input);
  return "That is " + second.toUpperCase();
});
console.log("replaced string is");
console.log(r);

输出：

replacing
matched   :this is a test
1st group :this is
2nd group :a test
pos       :0
input     :this is a test. and this is another one.
matched   :this is another one
1st group :this is
2nd group :another one
pos       :20
input     :this is a test. and this is another one.
replaced string is
That is A TEST. and That is ANOTHER ONE.

这是python版本-它甚至为每个组提供了开始/结束值：

#!/usr/bin/python
import re
s = "this is a test. and this is another one.";
print("replacing");

def repl(match):
    print "matched   :%s" %(match.string[match.start():match.end()])
    print "1st group :%s" %(match.group(1))
    print "2nd group :%s" %(match.group(2))
    print "position  :%d %d %d" %(match.start(), match.start(1), match.start(2))
    print "input     :%s" %(match.string)
    return "That is %s" %(match.group(2).upper())

print "replaced string is \n%s"%(re.sub(r"(this is) ([^.]+)", repl, s)) 

输出：

replacing
matched   :this is a test
1st group :this is
2nd group :a test
position  :0 0 8
input     :this is a test. and this is another one.
matched   :this is another one
1st group :this is
2nd group :another one
position  :20 20 28
input     :this is a test. and this is another one.
replaced string is 
That is A TEST. and That is ANOTHER ONE.

---

许多javascript、python等实现都允许您指定一个函数作为替换参数。函数通常将整个匹配字符串、其在输入字符串中的位置以及捕获的组作为参数。此函数返回的字符串用作替换文本

下面是使用JavaScript的方法：replace函数将整个匹配的子字符串作为第一个参数，捕获的组的值作为下一个n个参数，然后是原始输入字符串中匹配字符串的索引和整个输入字符串

var s = "this is a test. and this is another one.";
console.log("replacing");
r = s.replace(/(this is) ([^.]+)/g, function(match, first, second, pos, input) {
  console.log("matched   :" + match);
  console.log("1st group :" + first);
  console.log("2nd group :" + second);
  console.log("position  :" + pos);
  console.log("input     :" + input);
  return "That is " + second.toUpperCase();
});
console.log("replaced string is");
console.log(r);

输出：

replacing
matched   :this is a test
1st group :this is
2nd group :a test
pos       :0
input     :this is a test. and this is another one.
matched   :this is another one
1st group :this is
2nd group :another one
pos       :20
input     :this is a test. and this is another one.
replaced string is
That is A TEST. and That is ANOTHER ONE.

这是python版本-它甚至为每个组提供了开始/结束值：

#!/usr/bin/python
import re
s = "this is a test. and this is another one.";
print("replacing");

def repl(match):
    print "matched   :%s" %(match.string[match.start():match.end()])
    print "1st group :%s" %(match.group(1))
    print "2nd group :%s" %(match.group(2))
    print "position  :%d %d %d" %(match.start(), match.start(1), match.start(2))
    print "input     :%s" %(match.string)
    return "That is %s" %(match.group(2).upper())

print "replaced string is \n%s"%(re.sub(r"(this is) ([^.]+)", repl, s)) 

输出：

replacing
matched   :this is a test
1st group :this is
2nd group :a test
position  :0 0 8
input     :this is a test. and this is another one.
matched   :this is another one
1st group :this is
2nd group :another one
position  :20 20 28
input     :this is a test. and this is another one.
replaced string is 
That is A TEST. and That is ANOTHER ONE.

---

标准很可能不是，但您可以在某些实现中实现：$echo testx | perl-pe's/test/\U\1/'->TESTxMany实现javascript，python etc允许您指定一个函数作为替换参数-该函数通常将匹配的字符串和捕获的组作为参数，其返回值用作替换文本。@Amarghosh:您不妨将其作为答案发布，并在编写过程中添加一些示例代码。@Alan he还没有指定语言。@Amarghosh:所以请使用您最喜欢的语言。错误语言的示例比没有示例要好得多。标准很可能不是，但您可以在某些实现中实现：$echo testx | perl-pe's/test/\U\1/'->TESTxMany实现javascript，python etc允许您指定一个函数作为替换参数-该函数通常将匹配的字符串和捕获的组作为参数，其返回值用作替换文本。@Amarghosh:您不妨将其作为答案发布，并在编写过程中添加一些示例代码。@Alan he还没有指定语言。@Amarghosh:所以请使用您最喜欢的语言。一个错误语言的例子比没有好得多。9年后仍然是黄金。9年后仍然是黄金。