268 - recursive function: factorial

Is this really harder to reason about by being somehow 'operational' and
'abstraction free'? http://cacm.acm.org/magazines/2010/8/96632-an-interview-with-edsger-w-dijkstra/fulltext

1 files changed, 15 insertions, 0 deletions

diff --git a/factorial.mu b/factorial.mu
new file mode 100644
index 00000000..25ab1eba
--- /dev/null
+++ b/factorial.mu
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+(factorial
+  ((default-scope scope-address) <- new (scope literal) (30 literal))
+  ((n integer) <- arg)
+  { begin
+    ((zero? boolean) <- eq (n integer) (0 literal))
+    (break-unless (zero? boolean))
+    (reply (1 literal))
+  }
+  ((x integer) <- sub (n integer) (1 literal))
+  ((subresult integer) <- factorial (x integer))
+  ((result integer) <- mul (subresult integer) (n integer))
+  (reply (result integer)))
+
+(main
+  ((1 integer) <- factorial (5 literal)))