CODEWITHSUNDEEP
antlr4
JayDee
JayDee

Reputation: 959

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

In ANTLR v4, how do we parse this kind of string with double quote escaped double quotes like in VBA?

for text:

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

the goal would be to identify the string: some string with "john doe" in it

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

Upvotes: 11

Views: 8237

Answers (1)

Bart Kiers
Bart Kiers

Reputation: 170148

Like this:

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

where ~[\r\n"] | '""' means:

~[\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?

Not without embedding custom code. In Java that could look like:

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);
   }
 ;

Upvotes: 17

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