Add (net ricketyspace sicp two eighteen).

1 files changed, 14 insertions, 0 deletions

diff --git a/net/ricketyspace/sicp/two/eighteen.scm b/net/ricketyspace/sicp/two/eighteen.scm
new file mode 100644
index 0000000..f2ac60e
--- /dev/null
+++ b/net/ricketyspace/sicp/two/eighteen.scm
@@ -0,0 +1,14 @@
+;;;; License: CC0-1.0
+
+(define-module (net ricketyspace sicp two eighteen)
+  #:use-module (net ricketyspace sicp two seventeen)
+  #:export (sicp-reverse))
+
+(define (sicp-append list1 list2)
+  (if (null? list1)
+      list2
+      (cons (car list1) (sicp-append (cdr list1) list2))))
+
+(define (sicp-reverse items)
+  (cond ((null? items) '())
+        (else (sicp-append (sicp-reverse (cdr items)) (list (car items))))))