3 files changed, 93 insertions(+), 2 deletions(-)

M src/Bare.php
A src/Integer.php
M tests/PrimitivesTest.php

@@ 16,6 16,8 @@ class Bare
                 $val = substr($mess, 0, $length);
                 $mess = substr($mess, $length);
                 return $val;
+            case 'integer': // int
+                return (new Integer($mess))->get();
         };
     }
 


@@ 32,8 34,7 @@ class Bare
                 // TODO: Use uint for string's length.
                 return UInt::fromValue(strlen($value))->mess() . $value;
             case 'integer': // int
-                // TODO: encode as variable length integer.
-                return chr($value);
+                return Integer::fromValue($value)->mess();
             case 'double': // f64
                 // TODO: encode this.
                 return chr(0) . chr(0) . chr(0) . chr(0);

@@ 0,0 1,56 @@
+<?php
+
+namespace BareMess;
+
+// We can't use "Int" as the name of this class as it's reserved by PHP.
+// Note: Bare::mess and Bare::construct will encode a PHP int as a \BareMess\Integer.
+class Integer
+{
+    use Mutatable;
+    private int $value = 0;
+
+    public function __construct(& $mess = null)
+    {
+        if ($mess === null){
+            return;
+        }
+        $this->value = 0;
+        // The LSB is the sign.
+        $sign = (ord($mess[0]) % 2) ? -1 : 1;
+        // We can't do this inside the loop because bitshifting by negative numbers is not allowed.
+        $this->value += (ord($mess[0]) & 0b01111110) >> 1;
+        for($i = 1; $i < strlen($mess) + 1; $i++) {
+            if (! (ord($mess[$i - 1]) & 0b10000000) ) {
+                $mess = substr($mess, $i);
+                $this->value *= $sign;
+                return;
+            }
+            // TODO: Throw an error if $mess is empty here.
+            // Least significant bits first
+            $this->value += (ord($mess[$i]) & 0b01111111) << (($i * 7) - 1);
+        }
+    }
+
+    public function mess()
+    {
+        $mess = '';
+        // The number of bytes should be greater than or equal to the number required,
+        // abs(value * 2) < pow(2, 7 * bytes)
+        $bytes = floor(log(abs($this->value) + 1, 2) / 7) + 1;
+        $bits = (abs($this->value) << 1 & 0b01111110) + ($this->value < 0);
+        if ($bytes != 1) {
+            $bits = $bits | 0b10000000;
+        }
+        $mess .= chr($bits);
+        for ($i = 1; $i < $bytes; $i++) {
+            // BARE encodes integers as little-endian (least significant first),
+            $bits = (abs($this->value) >> (($i * 7)-1)) & 0b01111111;
+            // with the most significant bit being set for all except the last byte.
+            if ($i != $bytes - 1) {
+                $bits = $bits | 0b10000000;
+            }
+            $mess .= chr($bits);
+        }
+        return $mess;
+    }
+}

@@ 6,6 6,7 @@ use BareMess\Bare;
 use BareMess\Example\Department;
 use BareMess\Example\PublicKey;
 use BareMess\{I8,I16,I32,I64};
+use BareMess\Integer;
 use BareMess\{U8,U16,U32,U64};
 use BareMess\UInt;
 use PHPUnit\Framework\TestCase;


@@ 59,6 60,39 @@ class PrimitivesTest extends TestCase
         $this->assertEquals("\x03", $dept->mess());
     }
 
+    public function testInteger()
+    {
+        // Various equivalent ints.
+        $mess = "\xC1\x80\x00\xC1\x00\x41";
+        $int = Bare::construct($mess, 0);
+        $this->assertEquals(-32, $int);
+        $int2 = Bare::construct($mess, 0);
+        $this->assertEquals(-32, $int2);
+        $int3 = Bare::construct($mess, 0);
+        $this->assertEquals(-32, $int3);
+        $this->assertEquals('', $mess);
+
+        $int = 300;
+        $this->assertEquals(UInt::fromValue(600)->mess(), Bare::mess($int));
+
+        // This is usually PHP_INT_MIN - 1 (BARE's ints are zig-zag encoded).
+        $int = Integer::fromValue(-9223372036854775807);
+        // Test round-tripping
+        $mess = $int->mess();
+        $int2 = new Integer($mess);
+        $this->assertEquals('', $mess);
+        $this->assertEquals(-9223372036854775807, $int->get());
+        $this->assertEquals(-9223372036854775807, $int2->get());
+
+        // Test largest value
+        $int = Integer::fromValue(9223372036854775807);
+        $mess = $int->mess();
+        $int2 = new Integer($mess);
+        $this->assertEquals('', $mess);
+        $this->assertEquals(9223372036854775807, $int->get());
+        $this->assertEquals(9223372036854775807, $int2->get());
+    }
+
     public function testIs()
     {
         $i8 = new I8();