diff --git a/lib/hafriedlander/Peg/Parser/FalseOnlyPackrat.php b/lib/hafriedlander/Peg/Parser/FalseOnlyPackrat.php
index ec2a8b5..e5c57e3 100644
--- a/lib/hafriedlander/Peg/Parser/FalseOnlyPackrat.php
+++ b/lib/hafriedlander/Peg/Parser/FalseOnlyPackrat.php
@@ -8,28 +8,34 @@
  * @author Hamish Friedlander
  */
 class FalseOnlyPackrat extends Basic {
-	function __construct( $string ) {
-		parent::__construct( $string ) ;
 
-		$this->packstatebase = \str_repeat( '.', \strlen( $string ) ) ;
-		$this->packstate = [] ;
-	}
+    public function __construct($string) {
 
-	function packhas( $key, $pos ) {
-		return isset( $this->packstate[$key] ) && $this->packstate[$key][$pos] == 'F' ;
-	}
+		parent::__construct($string);
+		$this->packstate = [];
 
-	function packread( $key, $pos ) {
-		return \false ;
-	}
+    }
+
+    public function packhas($key, $pos) {
+		return ($this->packstate[$key][$pos] ?? false) == 'F';
+    }
 
-	function packwrite( $key, $pos, $res ) {
-		if ( !isset( $this->packstate[$key] ) ) $this->packstate[$key] = $this->packstatebase ;
+    public function packread($key, $pos) {
+        return \false;
+    }
 
-		if ( $res === \false ) {
-			$this->packstate[$key][$pos] = 'F' ;
-		}
+    public function packwrite($key, $pos, $result) {
+
+		if (!isset($this->packstate[$key])) {
+            $this->packstate[$key] = [];
+        }
+
+        if ($result === \false) {
+            $this->packstate[$key][$pos] = 'F';
+        }
+
+		return $result;
 
-		return $res ;
 	}
+
 }