[Jscheme-user] treating #null as #f in conditionals?

[Ken A. <kan...@bb...>]

Here's a proposal.

I think (and i know Rusty really does) think JScheme handling of #null is awk weird.  What if in conditionals we treated #null as #f.  This would make code more scheme like, here are 2 examples.

#null is currently treated at #t in conditionals but this change may not break much code.


(define (default  value default)
  ;; Before 
  (if (isNull value) default
      value))

(define (default value default)
  ;; After.
  (or value default))

(define (memoize key table computation)
  ;; Before.
  (let ((it (.get key table)))
    (if (not (isNull it)) it
	(let ((it (computation key)))
	  (.put table key it)
	  it))))

(define (memoize key table computation)
  ;; After.
  (or (.get key table)
      (let ((it (computation key)))
	  (.put table key it)
	  it)))