1 files changed, 116 insertions, 0 deletions
diff --git a/includes/libs/ExplodeIterator.php b/includes/libs/ExplodeIterator.php
new file mode 100644
index 00000000..3b34d9bc
--- /dev/null
+++ b/includes/libs/ExplodeIterator.php
@@ -0,0 +1,116 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * An iterator which works exactly like:
+ *
+ * foreach ( explode( $delim, $s ) as $element ) {
+ *    ...
+ * }
+ *
+ * Except it doesn't use 193 byte per element
+ */
+class ExplodeIterator implements Iterator {
+	// The subject string
+	private $subject, $subjectLength;
+
+	// The delimiter
+	private $delim, $delimLength;
+
+	// The position of the start of the line
+	private $curPos;
+
+	// The position after the end of the next delimiter
+	private $endPos;
+
+	// The current token
+	private $current;
+
+	/**
+	 * Construct a DelimIterator
+	 * @param string $delim
+	 * @param string $subject
+	 */
+	public function __construct( $delim, $subject ) {
+		$this->subject = $subject;
+		$this->delim = $delim;
+
+		// Micro-optimisation (theoretical)
+		$this->subjectLength = strlen( $subject );
+		$this->delimLength = strlen( $delim );
+
+		$this->rewind();
+	}
+
+	public function rewind() {
+		$this->curPos = 0;
+		$this->endPos = strpos( $this->subject, $this->delim );
+		$this->refreshCurrent();
+	}
+
+	public function refreshCurrent() {
+		if ( $this->curPos === false ) {
+			$this->current = false;
+		} elseif ( $this->curPos >= $this->subjectLength ) {
+			$this->current = '';
+		} elseif ( $this->endPos === false ) {
+			$this->current = substr( $this->subject, $this->curPos );
+		} else {
+			$this->current = substr( $this->subject, $this->curPos, $this->endPos - $this->curPos );
+		}
+	}
+
+	public function current() {
+		return $this->current;
+	}
+
+	/**
+	 * @return int|bool Current position or boolean false if invalid
+	 */
+	public function key() {
+		return $this->curPos;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function next() {
+		if ( $this->endPos === false ) {
+			$this->curPos = false;
+		} else {
+			$this->curPos = $this->endPos + $this->delimLength;
+			if ( $this->curPos >= $this->subjectLength ) {
+				$this->endPos = false;
+			} else {
+				$this->endPos = strpos( $this->subject, $this->delim, $this->curPos );
+			}
+		}
+		$this->refreshCurrent();
+
+		return $this->current;
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function valid() {
+		return $this->curPos !== false;
+	}
+}