ref: debf3fd5179629f8da5764b65ed3b870bab4cce5
dir: /femtolisp/wt.lsp/
(set! i 0)
(define-macro (while- test . forms)
`((label -loop- (lambda ()
(if ,test
(begin ,@forms
(-loop-))
nil)))))
(while (< i 10000000) (set! i (+ i 1)))