From db95b092e5e57ca7fcc7f58687594bc1e445d3d1 Mon Sep 17 00:00:00 2001
From: Artemy <artegoser@gmail.com>
Date: Mon, 15 Aug 2022 18:52:32 +0300
Subject: [PATCH] doc: factorial

---
 examples/factorial.json5 | 77 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 examples/factorial.json5

diff --git a/examples/factorial.json5 b/examples/factorial.json5
new file mode 100644
index 0000000..8f57383
--- /dev/null
+++ b/examples/factorial.json5
@@ -0,0 +1,77 @@
+[
+  {
+    fn: {
+      name: "fact",
+      args: ["n"],
+      body: [
+        { let: { result: { var: "fact.n" } } },
+        {
+          loop: [
+            //using loop because recursion is not supported
+            {
+              if: {
+                condition: { comp: [{ var: "fact.n" }, ">", 1] },
+                body: [
+                  {
+                    assign: {
+                      "fact.n": {
+                        calc: [{ var: "fact.n" }, "-", 1],
+                      },
+                    },
+                  },
+                  {
+                    assign: {
+                      result: {
+                        calc: [{ var: "result" }, "*", { var: "fact.n" }],
+                      },
+                    },
+                  },
+                ],
+                else: ["break"],
+              },
+            },
+          ],
+        },
+        { return: { var: "result" } },
+      ],
+    },
+  },
+
+  {
+    fn: {
+      name: "_eq",
+      args: ["a", "b"],
+      body: [{ return: { comp: [{ var: "_eq.a" }, "==", { var: "_eq.b" }] } }],
+    },
+  },
+
+  ["10! == 3 628 800: ", { _eq: [{ fact: [10] }, 3628800] }],
+  ["11! == 39 916 800: ", { _eq: [{ fact: [11] }, 39916800] }],
+
+  ["12! == 479 001 600: ", { _eq: [{ fact: [12] }, 479001600] }],
+  ["13! == 6 227 020 800: ", { _eq: [{ fact: [13] }, 6227020800] }],
+
+  ["14! == 87 178 291 200: ", { _eq: [{ fact: [14] }, 87178291200] }],
+  ["15! == 1 307 674 368 000: ", { _eq: [{ fact: [15] }, 1307674368000] }],
+
+  ["16! == 20 922 789 888 000: ", { _eq: [{ fact: [16] }, 20922789888000] }],
+  ["17! == 355 687 428 096 000: ", { _eq: [{ fact: [17] }, 355687428096000] }],
+
+  [
+    "18! == 6 402 373 705 728 000: ",
+    { _eq: [{ fact: [18] }, 6402373705728000] },
+  ],
+  [
+    "19! == 121 645 100 408 832 000: ",
+    { _eq: [{ fact: [19] }, 121645100408832000] },
+  ],
+
+  [
+    "20! == 2 432 902 008 176 640 000: ",
+    { _eq: [{ fact: [20] }, 2432902008176640000] },
+  ],
+  // [
+  //   "21! == 51 090 942 171 709 440 000: ",
+  //   { _eq: [{ fact: [21] }, 51090942171709440000] },
+  // ], some json and yaml troubles with number `51090942171709440000`
+]