antlr4 - ANTLRv4 : How to read double quote escaped double quotes in string?

Question

在ANTLR v4中，我们如何像VBA中那样用双引号转义的双引号解析这种字符串？

对于文本:

"some string with ""john doe"" in it"

目标是识别字符串: some string with "john doe" in it
可以重写它以将双双引号转换为单双引号吗？ "" -> "？

Answer 1

像这样:

STRING
 : '"' (~[\r\n"] | '""')* '"'
 ;

其中 ~[\r\n"] | '""'的意思是:

~[\r\n"]    # any char other than '\r', '\n' and double quotes
|           # OR
'""'        # two successive double quotes

And is it possible to rewrite it to turn double double quotes in single double quotes?

并非没有嵌入自定义代码。在Java中可能看起来像:

STRING
 : '"' (~[\r\n"] | '""')* '"' 
   {
     String s = getText();
     s = s.substring(1, s.length() - 1); // strip the leading and trailing quotes
     s = s.replace("\"\"", "\""); // replace all double quotes with single quotes
     setText(s);
   }
 ;