1 files changed, 29 insertions, 0 deletions
diff --git a/ack.kpl b/ack.kpl
new file mode 100644
index 0000000..80a3a74
--- /dev/null
+++ b/ack.kpl
@@ -0,0 +1,29 @@
+
+// Ackermann function
+
+`export ack : Fn[m; n] $ (
+    ? !=(`type m; `type n) {
+        `exit "m and n must be the same type and above zero"
+    }
+    ? {
+        m = 0 { n + 1 }
+        &(m > 0; n = 0) { ack `call_sync (m - 1; 1) }
+        &(m > 0; n > 0) { ack `call_sync (m - 1; ack `call_sync (m; n - 1)) }
+        { 0 }
+    }
+)
+
+`export ack_string : Fn[m; n] $ (
+    String $ ("ack("; m; " "; n; ") = "; ack `call_sync (m; n); "\n")
+)
+
+`is_main Fn $ (
+    ( args ) : `use "sys"
+    ? 4 != `length args {
+         `return `error String $ (
+            "Got: "; " " `join args; "\n"
+            "Usage: "; args `get 0; " "; args `get 1; " <m> <n>\n"
+         )
+    }
+    `print ack_string `call_sync (I64 $ args `get -2; I64 $ args `get -1)
+)