The implementation of the Rascal meta-programming language (including interpreter, type checker, parser generator, compiler and JVM based run-time system)
Addition w.r.t. undocumented features; it also does not make any mention of when clauses. They are never mentioned in the documentation I believe - also not for switch cases.
Describe the bug
https://www.rascal-mpl.org/docs/Rascal/Declarations/Function/
This document:
extend
I write it here so I will not forget about this.