[foobarbaz1234]

The traditional theories about parsing and their implementations in tools like yacc, lex, antlr, etc. are not that important in practice. I also used them in some university courses, but after I encountered parsing problems in practice it seemed easier to just implement a recursive descent parser in the host language.

First, you have to learn the DSL's of these tools (which are non-trivial in detail). Second you have to integrate them into your toolchain. Third - and that is my biggest complaint - you have to connect the Parser combinator's AST to your domain AST. The last thing is pretty amusing as I consider it the main purpose of a parser.

In practice (hopefully after evaluating the need for a custom data format as it might be possible to hijack existing languages and standards) I either use a combinator-parser (if FP available) or an ad-hoc recursive descent parser. Maybe I consider a lexer but the representation of tokens is also a non-trivial decision.