| In arc, it seems that '() and nil are equivalent. (Specifically, '() evaluates to nil.) Searching through arc.arc, it looks like people just use nil and ignore the existence of '(). However, ac.scm makes a big deal of the difference between the symbol 'nil and the empty list '(). Can we just do (define nil '())?
This would let us redefine the other functions in cleaner, simpler ways, and I don't think it would change semantics at all.(For instance, (define (ar-false? x)
(and x (not (null? x)))).
And all of the list-nilling functions would be unnecessary.) |
