aatree and linked-listHEADmaster

1 files changed, 27 insertions, 0 deletions

diff --git a/examples/linked-list.scm b/examples/linked-list.scm
new file mode 100644
index 0000000..821d0b6
--- /dev/null
+++ b/examples/linked-list.scm
@@ -0,0 +1,27 @@
+(define-namespace linked-list
+  (define-record-type linked-list
+    (linked-list head tail)
+    linked-list?
+    (head get-head set-head!)
+    (tail get-tail set-tail!))
+  (define (new) (linked-list '() '()))
+  (define (empty? lst) (null? (get-head lst)))
+  (define (linked-list->list lst) (get-head lst))
+  (define (push-first lst val)
+    (let ((container (list val)))
+      (set-head! lst container)
+      (set-tail! list container)))
+  (define (push-head lst val)
+    (if (empty? lst)
+        (push-first lst val)
+        (set-head! lst (cons val (get-head lst)))))
+  (define (push-tail lst val)
+    (if (empty? lst)
+        (push-first lst val)
+        (let ((container (list val)))
+          (set-cdr! (get-tail lst) container)
+          (set-tail! lst container))))
+  (export new empty?
+          push-head push-tail
+          linked-list->list))
+