But first...
Some things to know about core Rakudo hacking:
- Simple things often aren't
- e.g., :by() adverbs on Ranges ( 1..10:by(2) )
- e.g., lexical variables
- Hard things often aren't
- e.g., .assuming() on subroutines
- Start by reviewing synopses and test suite ...
- ...but don't blindly accept everything you see there.