如何在 ANTLR4 中的字符串中包含引号

Question

How can I include quotes for string and characters as part of the string. Example is "This is a \\" string" which should result in one string instead of "This is a \\" as one string and string" as an error in this case. The same goes for the characters. Example is '\\'', but in my case it's only '\\'.

This is my current solution which works only without quotes.

CHARACTER : '\\'' ~('\\'')+ '\\'' ;

STRING : '"' ~('"')+ '"' ;

Answer 1

Your string/char rules don't handle escape sequences correctly. For the character it should be:

CHARACTER: '\'' '\\'? '.' '\'';

Here we make the escape char (backshlash) be part of the rule and require an additional char (whatever it is) follow it. Similar for the string:

STRING: '"' ('\\'? .)+? '"';

By using +? we are telling ANTLR4 to match in a non-greedy manner, stopping at the first non-escaped quote char after the initial one.