5485 - promote SubX to top-level

1 files changed, 35 insertions, 0 deletions

diff --git a/archive/1.vm.arc/tangle.mu b/archive/1.vm.arc/tangle.mu
new file mode 100644
index 00000000..3e73dd89
--- /dev/null
+++ b/archive/1.vm.arc/tangle.mu
@@ -0,0 +1,35 @@
+; To demonstrate tangle directives, we'll construct a factorial function with
+; separate base and recursive cases. Compare factorial.mu.
+; This isn't a very realistic example, just a simple demonstration of
+; possibilities.
+
+(function factorial [
+  (default-space:space-address <- new space:literal 30:literal)
+  (n:integer <- next-input)
+  { begin
+    base-case
+  }
+  recursive-case
+])
+
+(after base-case [
+  ; if n=0 return 1
+  (zero?:boolean <- equal n:integer 0:literal)
+  (break-unless zero?:boolean)
+  (reply 1:literal)
+])
+
+(after recursive-case [
+  ; return n*factorial(n-1)
+  (x:integer <- subtract n:integer 1:literal)
+  (subresult:integer <- factorial x:integer)
+  (result:integer <- multiply subresult:integer n:integer)
+  (reply result:integer)
+])
+
+(function main [
+  (1:integer <- factorial 5:literal)
+  ($print (("result: " literal)))
+  (print-integer nil:literal/terminal 1:integer)
+  (print-character nil:literal/terminal ((#\newline literal)))
+])