From dc593f76aaa52943c62ec6e66346a973b5732f72 Mon Sep 17 00:00:00 2001
From: Brian Mock <brian@mockbrian.com>
Date: Wed, 11 Jul 2018 07:34:07 -0700
Subject: [PATCH] Create binary.js

---
 examples/binary.js | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 examples/binary.js

diff --git a/examples/binary.js b/examples/binary.js
new file mode 100644
index 0000000..d0bc87e
--- /dev/null
+++ b/examples/binary.js
@@ -0,0 +1,41 @@
+"use strict";
+
+// Run me with Node to see my output!
+
+let util = require("util");
+let P = require("..");
+let B = P.Binary;
+
+///////////////////////////////////////////////////////////////////////
+
+let Lang = P.createLanguage({
+  File: p => p.MagicNumber.then(p.Int32Array),
+  MagicNumber: () => P.seq(B.byte(0x13), B.byte(0x37)),
+  Int32: () => B.int32BE,
+  Uint32: () => B.uint32BE,
+  Int32Array: p => p.Uint32.chain(n => p.Int32.times(n))
+});
+
+///////////////////////////////////////////////////////////////////////
+
+// File format:
+// - Magic number: hexadecimal "1337" byte sequence
+// - Array length: 32-bit unsigned big-endian integer
+// - 32-bit signed integers up to the array length
+// - End of file
+
+let magic = [0x13, 0x37];
+let length = [0x00, 0x00, 0x00, 0x02];
+let n512 = [0x00, 0x00, 0x02, 0x00];
+let n513 = [0x00, 0x00, 0x02, 0x01];
+let bytes = [].concat(magic, length, n512, n513);
+let input = Buffer.from(bytes);
+
+function prettyPrint(x) {
+  let opts = { depth: null, colors: "auto" };
+  let s = util.inspect(x, opts);
+  console.log(s);
+}
+
+let ast = Lang.File.tryParse(input);
+prettyPrint(ast);