Praspel (PHP Realistic Annotation and Specification Language) is a formal specification language for PHP. It is based on the design-by-contract paradigm and uses preconditions, postconditions, invariants etc. Specifications are written in the comments of the PHP code (always accessible). Praspel is used for manual or automatic software validation and verification, thanks to realistic domains.
This library contains compiler, interpreter, visitors, iterators and other tools around the Praspel language.
An interesting related project is atoum/praspel-extension.
This is a companion discussion topic for the original entry at https://hoa-project.net/En/Literature/Hack/Praspel.html