X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fscheme-library-5-lists.scm;fp=src%2Fscheme-library-5-lists.scm;h=12bd3c345f0c026e63a7eb6e160d5ccdb3bc866f;hb=41b469d050586a05cd43fdd4c78755616af3f7b4;hp=0000000000000000000000000000000000000000;hpb=34c8e9e803a2257d9234b1381ad4eef725e224da;p=scheme.forth.jl.git

diff --git a/src/scheme-library-5-lists.scm b/src/scheme-library-5-lists.scm
new file mode 100644
index 0000000..12bd3c3
--- /dev/null
+++ b/src/scheme-library-5-lists.scm
@@ -0,0 +1,16 @@
+;; LISTS
+
+; Return number of items in list
+(define (length l)
+  (define (iter a count)
+    (if (null? a)
+      count
+      (iter (cdr a) (fix:+ count 1))))
+  (iter l 0))
+
+; Reverse the contents of a list
+(define (reverse l)
+  (if (null? l)
+    ()
+    (append (reverse (cdr l)) (list (car l)))))
+