> call out to other parsing functions yes, regular expressions cannot do that because regular languages cannot do that. that is an important limitation of regu

> call out to other parsing functions yes, regular expressions cannot do that because regular languages cannot do that. that is an important limitation of regular languages, otherwise you'd be able to match the language {a^nb^n for any n} (or more specifically, balanced parentheses). The thing you wrote you wouldn't want to parse with a regular expression because it fundamentally doesn't look like a regular language with its hierarchical structure.