tisp

commit 49174e20cfaa071931f5b5b19d43f0e01e22a412
parent 58a0240520c7974cb02184d4e6738094484daec3
Author: Ed van Bruggen <edvb@uw.edu>
Date:   Tue, 24 Dec 2019 00:54:53 -0800

Define English list element accessors

Diffstat:
tibs/lib.tsp
 | 
11
+++++++++++

1 file changed, 11 insertions(+), 0 deletions(-)
diff --git a/tibs/lib.tsp b/tibs/lib.tsp
@@ -177,6 +177,17 @@
 (define (member mem lst)
   (memp (lambda (x) (= mem x)) lst))
 
+; define English list element accessors
+(define rest cdr) ; TODO first and rest are generics for list, vec, str types
+(define first car)
+(let (((def name count)
+       (list 'define (list name 'x) (list 'nth 'x count))))
+  (recur f ((n 1)
+            (lst '(second third forth fifth sixth seventh eighth ninth tenth)))
+         (when lst
+           (eval (def (car lst) n))
+           (f (+ n 1) (cdr lst)))))
+
 ;;; Stacks
 (define (push stack val)
   (cons val stack))