From 605026c6c6a8270e6af415be90937d6928e4dd7c Mon Sep 17 00:00:00 2001
From: Ropel <ropel@ropel.it>
Date: Wed, 30 May 2018 18:50:38 +0200
Subject: [PATCH] added nextSetBit

---
 examples/BitArray.php     | 16 +++++++++++-
 src/BitArray/BitArray.php | 51 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/examples/BitArray.php b/examples/BitArray.php
index e3b2c51..bec2162 100644
--- a/examples/BitArray.php
+++ b/examples/BitArray.php
@@ -13,7 +13,9 @@
  * This file is part of the php-bitarray package https://github.com/chdemko/php-bitarray
  */
 
-require __DIR__ . '/../vendor/autoload.php';
+//require __DIR__ . '/../vendor/autoload.php';
+require __DIR__ . '/../src/BitArray/BitArray.php';
+require __DIR__ . '/../src/BitArray/Iterator.php';
 
 use chdemko\BitArray\BitArray;
 
@@ -43,3 +45,15 @@
 
 // Print [true,true,true,false,true]
 echo json_encode($bits) . PHP_EOL;
+
+// Print 14
+$bits = BitArray::fromString('1100000000000010');
+echo $bits->nextSetBit(4) . PHP_EOL;
+
+// print 3 to 30
+for($i = 2;$i < 30; $i++)
+{
+	$str = str_pad('10',$i,'0');
+	$bits = BitArray::fromString($str . '100');
+	echo $str . " -- " . $bits->nextSetBit(2) . PHP_EOL;
+}
diff --git a/src/BitArray/BitArray.php b/src/BitArray/BitArray.php
index 7812d94..9e7206d 100644
--- a/src/BitArray/BitArray.php
+++ b/src/BitArray/BitArray.php
@@ -208,7 +208,8 @@ public function offsetGet($offset)
 			throw new \OutOfRangeException('Argument offset must be a positive integer lesser than the size');
 		}
 	}
-
+	
+	
 	/**
 	 * Set the truth value for an index
 	 *
@@ -801,4 +802,52 @@ public function shift($size = 1, $value = false)
 
 		return $this;
 	}
+
+
+	/**
+	 * Returns the index of the first bit that is set to true that occurs on or after the specified starting index. If no such bit exists then -1 is returned.
+	 *
+	 * @param   integer  $offset  The offset
+	 *
+	 * @return  boolean  The truth value
+	 *
+	 * @throw   \OutOfRangeException  Argument index must be an positive integer lesser than the size
+	 *
+	 * @since   1.0.0
+	 */
+	public function nextSetBit($offset)
+	{
+		if ($this->offsetExists($offset))
+		{
+			$ret = $offset;
+			while(( $ret % 8 )!=0)
+			{
+				if($this[$ret])
+					return $ret;
+				else
+					$ret++;
+			}
+			if (!$this->offsetExists($ret))
+				return -1;
+			while($this->data[(int) ($ret / 8)]==chr(0))
+			{
+				//echo "$ret - " . $this->data[(int) ($ret / 8)] . " !\n";
+				$ret += 8;
+				if (!$this->offsetExists($ret))
+					return -2;
+			}
+			while($ret < $this->size)
+			{
+				if($this[$ret])
+					return $ret;
+				else
+					$ret++;
+			}
+			return -3;
+		}
+		else
+		{
+			throw new \OutOfRangeException('Argument offset must be a positive integer lesser than the size');
+		}
+	}
 }