pyformlang.regular_expression.regex_objects.MisformedRegexError: Wrong parenthesis regex Regex about pyformlang

[Aunsiels]

I think @IlyaEp will know better what was the purpose of these methods and how to use them.

The CFG.from_text method is not designed to receive a regex. In the documentation:

The structure of a production is:
head -> body1 | body2 | ... | bodyn
where | separates the bodies.

This is just a shortcut for:
head -> body1
head -> body2
...

The "|" symbol is not related to the regex "|" symbol. Each body is composed of terminals and variables, as a concatenation. That's it.

This representation is similar to the one used in NLTK.

I am not sure if RSAs are supposed to support these kinds of operations. Maybe both "from_text" and "from_cfg" methods are required? @IlyaEp was the one who created RSA, he might have an opinion on this.