Smalltalk requires explicit labeling of all but the first argument (though they are ordered) for keyword messages. Good naming conventions can make this enjoyab

Smalltalk requires explicit labeling of all but the first argument (though they are ordered) for keyword messages. Good naming conventions can make this enjoyable (at least subjectively). In a hashmap based lisp, I'd expect defun to look something like (define-function: (foo-with-a: a b: b c: c) with-body: ...) Of course, since you're using an unordered representation, one could instead say (with-body: ... define-function: (c: c b: b foo-with-a: a)), which is significantly more confusing. This also means you probably can't do implicit progn. progn in general will probably be unpleasant, unfortunately, unless one includes syntactic sugar for ordered sequences, which might defeat the purpose of an associative-array-based Lisp. The first thing I've noticed about a vector-based Lisp is that you actually need primitive integers so that you can do indexing, which isn't the case with cons-cell based Lisps.