Add fibonacci code and tests

2 files changed, 40 insertions, 0 deletions

diff --git a/fibonacci/fibonacci-test.scm b/fibonacci/fibonacci-test.scm
new file mode 100644
index 0000000..f0cb6bf
--- /dev/null
+++ b/fibonacci/fibonacci-test.scm
@@ -0,0 +1,23 @@
+(use-modules (srfi srfi-64)
+             (fibonacci))
+
+(test-begin "harness")
+
+(test-equal "length-zero-sequence"
+  '()
+  (fibonacci 0))
+
+(test-equal "length-one-sequence"
+  '(0)
+  (fibonacci 1))
+
+(test-equal "length-three-sequence"
+  '(0 1 1)
+  (fibonacci 3))
+
+(test-equal "length-fifteen-ssequence"
+  '(0 1 1 2 3 5 8 13 21 34 55 89 144 233 377)
+  (fibonacci 15))
+
+
+(test-end "harness")
diff --git a/fibonacci/fibonacci.scm b/fibonacci/fibonacci.scm
new file mode 100644
index 0000000..8563587
--- /dev/null
+++ b/fibonacci/fibonacci.scm
@@ -0,0 +1,17 @@
+(define-module (fibonacci))
+
+
+(define-public (fibonacci k)
+  "Returns a fibonacci sequence of k length
+as a list"
+  (fibonacci-helper k 0 1 '()))
+
+(define (fibonacci-helper k n1 n2 lst)
+  "Recursively generates and appends numbers in the
+fibonacci sequence."
+  (if (zero? k)
+      lst
+      (fibonacci-helper (- k 1)
+                        n2
+                        (+ n1 n2)
+                        (append lst (list n1)))))