The primary focus of funcparserlib is parsing little languages or
external DSLs (domain specific languages).

Parsers made with funcparserlib are pure-Python LL(*) parsers. It
means that it's very easy to write parsers without thinking about
lookaheads and other hardcore parsing stuff. However, recursive
descent parsing is a rather slow method compared to LL(k) or LR(k)
algorithms. Still, parsing with funcparserlib is at least twice
faster than PyParsing, a very popular library for Python.

The source code of funcparserlib is only 1.2K lines of code, with
lots of comments. Its API is fully type hinted. It features the
longest parsed prefix error reporting, as well as a tiny lexer
generator for token position tracking.

The idea of parser combinators used in funcparserlib comes from the
Introduction to Functional Programming course. We have converted
it from ML into Python.