Added an example to illustrate how husk-scheme implements proper tail recursion.

Author: justinethier

examples/tco.scm

@@ -0,0 +1,7 @@
+; This example proves that a Scheme implements proper tail recursion (or tail call optimization, or TCO).
+;
+; TCO isn't just about self-calling. The following is expected to run forever in scheme. It will use ~100% CPU, however memory usage is expected to remain constant and a stack overflow should never occur:
+;
+(define (foo) (bar))
+(define (bar) (foo))
+(foo)