From 0a068dfea48f91c4590a88f58081254c72ca282f Mon Sep 17 00:00:00 2001
From: Zach DeCook <zachdecook@librem.one>
Date: Sat, 27 Jun 2020 10:15:23 -0400
Subject: [PATCH] * I8, I16, I32, I64: Implement mess

---
 src/I.php                | 25 +++++++++++++++++++++++++
 src/I16.php              |  1 +
 src/I32.php              |  1 +
 src/I64.php              |  1 +
 src/I8.php               |  1 +
 src/Is.php               |  8 ++++++++
 tests/PrimitivesTest.php | 27 +++++++++++++++++++++++++++
 7 files changed, 64 insertions(+)
 create mode 100644 src/I.php
 create mode 120000 src/I16.php
 create mode 120000 src/I32.php
 create mode 120000 src/I64.php
 create mode 120000 src/I8.php
 create mode 100644 src/Is.php

diff --git a/src/I.php b/src/I.php
new file mode 100644
index 0000000..12ffe95
--- /dev/null
+++ b/src/I.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace BareMess;
+
+abstract class I
+{
+    use Mutatable;
+    private int $value = 0;
+
+    public function mess()
+    {
+        $mess = '';
+        for ($i = 0; $i < get_called_class()::BYTES; $i++) {
+            // BARE encodes integers as little-endian (least significant first).
+            // Twos complement.
+            if ($this->value <= 0) {
+                // chr makes binary string of least significant byte.
+                $mess .= chr(abs($this->value) >> ($i * 8));
+            } else {
+                $mess .= chr(0xFF - (($this->value - 1) >> ($i * 8)) );
+            }
+        }
+        return $mess;
+    }
+}
diff --git a/src/I16.php b/src/I16.php
new file mode 120000
index 0000000..c93c919
--- /dev/null
+++ b/src/I16.php
@@ -0,0 +1 @@
+Is.php
\ No newline at end of file
diff --git a/src/I32.php b/src/I32.php
new file mode 120000
index 0000000..c93c919
--- /dev/null
+++ b/src/I32.php
@@ -0,0 +1 @@
+Is.php
\ No newline at end of file
diff --git a/src/I64.php b/src/I64.php
new file mode 120000
index 0000000..c93c919
--- /dev/null
+++ b/src/I64.php
@@ -0,0 +1 @@
+Is.php
\ No newline at end of file
diff --git a/src/I8.php b/src/I8.php
new file mode 120000
index 0000000..c93c919
--- /dev/null
+++ b/src/I8.php
@@ -0,0 +1 @@
+Is.php
\ No newline at end of file
diff --git a/src/Is.php b/src/Is.php
new file mode 100644
index 0000000..3b782fe
--- /dev/null
+++ b/src/Is.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace BareMess;
+
+class I8 extends I {public const BYTES = 1;}
+class I16 extends I {public const BYTES = 2;}
+class I32 extends I {public const BYTES = 4;}
+class I64 extends I {public const BYTES = 8;}
diff --git a/tests/PrimitivesTest.php b/tests/PrimitivesTest.php
index ecd6847..583408a 100644
--- a/tests/PrimitivesTest.php
+++ b/tests/PrimitivesTest.php
@@ -3,6 +3,7 @@
 namespace BareMess\Tests;
 
 use BareMess\Example\PublicKey;
+use BareMess\{I8,I16,I32,I64};
 use BareMess\{U8,U16,U32,U64};
 use PHPUnit\Framework\TestCase;
 
@@ -30,6 +31,32 @@ class PrimitivesTest extends TestCase
         $this->assertEquals($value, $pk3->get());
     }
 
+    public function testIs()
+    {
+        $i8 = new I8();
+        $this->assertEquals("\0", $i8->mess());
+        $i8->set(1);
+        $this->assertEquals("\xFF", $i8->mess());
+        $i8->set(-1);
+        $this->assertEquals("\x01", $i8->mess());
+
+        $i64 = new I64();
+        $this->assertEquals(0, $i64->get());
+        // Largest representable value.
+        $i64->set(0x7FFFFFFFFFFFFFFF);
+        // Twos complement max int looks like 0b1000...0001,
+        // note that this is little endian.
+        $this->assertEquals("\x01\0\0\0\0\0\0\x80", $i64->mess());
+
+        // Smallest representable value
+        $i64->set(-1 << 63);
+        $this->assertEquals(-0x7FFFFFFFFFFFFFFF - 1, $i64->get());
+        $this->assertEquals("\0\0\0\0\0\0\0\x80", $i64->mess());
+
+        $i64->set(1);
+        $this->assertEquals("\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF", $i64->mess());
+    }
+
     public function testUs()
     {
         $u8 = new U8();
-- 
2.45.2