From: Ramakrishnan Muthukrishnan Date: Mon, 4 Jun 2012 04:50:28 +0000 (+0530) Subject: rewrite `quote->cons' using `match'. X-Git-Url: https://git.rkrishnan.org/%5B/%5D%20/file/URI:LIT:krugkidfnzsc4/frontends/nxhtml.html?a=commitdiff_plain;h=002f83ea8883fdb3bcdafad16c967b67d9d34ba3;p=sicp.git rewrite `quote->cons' using `match'. --- diff --git a/src/sicp/eval-4.33.rkt b/src/sicp/eval-4.33.rkt index 67d821c..ffc7084 100644 --- a/src/sicp/eval-4.33.rkt +++ b/src/sicp/eval-4.33.rkt @@ -253,9 +253,9 @@ (define (quote->cons exp) ;(display (format "q->c: ~s~%" exp)) - (if (null? exp) - '() - (list 'cons (list 'quote (car exp)) (quote->cons (cdr exp))))) + (match exp + [(? null?) '()] + [_ `(cons (quote ,(car exp)) ,(quote->cons (cdr exp)))])) ;; eval (define (eval exp env)