Return the matched keyword from KEYWORD?
Add single-argument dict constructor, call it from DICT (avoids arg-length restrictions)
Add LIST-LENGTH-P and TO-BOOl utils
Fix issue with no-arg :K form
Match keyword literals as a :K form
Add :OPT form to replace (:? (:checkpoint ...)) forms
Signal an error when :BIND is used outside :WITH-BINDS
Reserve an argument for future parameters to :WITH-BINDS
Add :WITH-DICT-BIND/:KBIND rules for binding dict keys
Use :OPT and keyword literals in frame-phrase