Parser combinators with excellent error messages and error recovery

Parkour is a parser-combinator library for human-authored text such as configuration files, DSLs and small languages. It reports precise, well-rendered syntax errors with structured diagnostics, offers opt-in error recovery that reports many problems in one run, works on strings or token streams, and is stack-safe on long and deeply nested input (nesting depth is limited). It has no runtime dependencies beyond the OCaml standard library.