diff --git a/src/Editor.php b/src/Editor.php
index 9d78ac7..6d08cb9 100644
--- a/src/Editor.php
+++ b/src/Editor.php
@@ -12,7 +12,7 @@ use Aviat\Kilo\Tokens\PHP8;
 class Editor {
 	use Traits\MagicProperties;
 
-	private string $ab = '';
+	private string $outputBuffer = '';
 
 	protected int $cursorX = 0;
 	protected int $cursorY = 0;
@@ -189,7 +189,7 @@ class Editor {
 
 	protected function insertRow(int $at, string $s, bool $updateSyntax = TRUE): void
 	{
-		if ($at < 0 || $at > $this->numRows)
+		if ($at > $this->numRows)
 		{
 			return;
 		}
@@ -523,103 +523,111 @@ class Editor {
 		for ($y = 0; $y < $this->screenRows; $y++)
 		{
 			$filerow = $y + $this->rowOffset;
-			if ($filerow >= $this->numRows)
+
+			($filerow >= $this->numRows)
+				? $this->drawPlaceholderRow($y)
+				: $this->drawRow($filerow);
+
+			$this->outputBuffer .= ANSI::CLEAR_LINE;
+			$this->outputBuffer .= "\r\n";
+		}
+	}
+
+	protected function drawRow(int $rowIdx): void
+	{
+		$len = $this->rows[$rowIdx]->rsize - $this->colOffset;
+		if ($len < 0)
+		{
+			$len = 0;
+		}
+		if ($len > $this->screenCols)
+		{
+			$len = $this->screenCols;
+		}
+
+		$chars = substr($this->rows[$rowIdx]->render, $this->colOffset, (int)$len);
+		$hl = array_slice($this->rows[$rowIdx]->hl, $this->colOffset, (int)$len);
+
+		$currentColor = -1;
+
+		for ($i = 0; $i < $len; $i++)
+		{
+			$ch = $chars[$i];
+
+			// Handle 'non-printable' characters
+			if (is_ctrl($ch))
 			{
-				if ($this->numRows === 0 && $y === (int)($this->screenRows / 2))
+				$sym = (ord($ch) <= 26)
+					? chr(ord('@') + ord($ch))
+					: '?';
+				$this->outputBuffer .= ANSI::color(Color::INVERT);
+				$this->outputBuffer .= $sym;
+				$this->outputBuffer .= ANSI::RESET_TEXT;
+				if ($currentColor !== -1)
 				{
-					$welcome = sprintf('PHP Kilo editor -- version %s', KILO_VERSION);
-					$welcomelen = strlen($welcome);
-					if ($welcomelen > $this->screenCols)
-					{
-						$welcomelen = $this->screenCols;
-					}
-
-					$padding = ($this->screenCols - $welcomelen) / 2;
-					if ($padding > 0)
-					{
-						$this->ab .= '~';
-						$padding--;
-					}
-					for ($i = 0; $i < $padding; $i++)
-					{
-						$this->ab .= ' ';
-					}
-
-					$this->ab .= substr($welcome, 0, $welcomelen);
+					$this->outputBuffer .= ANSI::color($currentColor);
 				}
-				else
+			}
+			else if ($hl[$i] === Highlight::NORMAL)
+			{
+				if ($currentColor !== -1)
 				{
-					$this->ab .= '~';
+					$this->outputBuffer .= ANSI::RESET_TEXT;
+					$this->outputBuffer .= ANSI::color(Color::FG_WHITE);
+					$currentColor = -1;
 				}
+				$this->outputBuffer .= $ch;
 			}
 			else
 			{
-				$len = $this->rows[$filerow]->rsize - $this->colOffset;
-				if ($len < 0)
+				$color = syntax_to_color($hl[$i]);
+				if ($color !== $currentColor)
 				{
-					$len = 0;
-				}
-				if ($len > $this->screenCols)
-				{
-					$len = $this->screenCols;
+					$currentColor = $color;
+					$this->outputBuffer .= ANSI::RESET_TEXT;
+					$this->outputBuffer .= ANSI::color($color);
 				}
+				$this->outputBuffer .= $ch;
+			}
+		}
 
-				$c = substr($this->rows[$filerow]->render, $this->colOffset, $len);
-				$hl = array_slice($this->rows[$filerow]->hl, $this->colOffset, $len);
+		$this->outputBuffer .= ANSI::RESET_TEXT;
+		$this->outputBuffer .= ANSI::color(Color::FG_WHITE);
+	}
 
-				$currentColor = -1;
-
-				for ($i = 0; $i < $len; $i++)
-				{
-					// Handle 'non-printable' characters
-					if (is_ctrl($c[$i]))
-					{
-						$sym = (ord($c[$i]) <= 26)
-							? chr(ord('@') + ord($c[$i]))
-							: '?';
-						$this->ab .= ANSI::color(Color::INVERT);
-						$this->ab .= $sym;
-						$this->ab .= ANSI::RESET_TEXT;
-						if ($currentColor !== -1)
-						{
-							$this->ab .= ANSI::color($currentColor);
-						}
-					}
-					else if ($hl[$i] === Highlight::NORMAL)
-					{
-						if ($currentColor !== -1)
-						{
-							$this->ab .= ANSI::RESET_TEXT;
-							$this->ab .= ANSI::color(Color::FG_WHITE);
-							$currentColor = -1;
-						}
-						$this->ab .= $c[$i];
-					}
-					else
-					{
-						$color = syntax_to_color($hl[$i]);
-						if ($color !== $currentColor)
-						{
-							$currentColor = $color;
-							$this->ab .= ANSI::RESET_TEXT;
-							$this->ab .= ANSI::color($color);
-						}
-						$this->ab .= $c[$i];
-					}
-				}
-
-				$this->ab .= ANSI::RESET_TEXT;
-				$this->ab .= ANSI::color(Color::FG_WHITE);
+	protected function drawPlaceholderRow(int $y): void
+	{
+		if ($this->numRows === 0 && $y === (int)($this->screenRows / 2))
+		{
+			$welcome = sprintf('PHP Kilo editor -- version %s', KILO_VERSION);
+			$welcomelen = strlen($welcome);
+			if ($welcomelen > $this->screenCols)
+			{
+				$welcomelen = $this->screenCols;
 			}
 
-			$this->ab .= ANSI::CLEAR_LINE;
-			$this->ab .= "\r\n";
+			$padding = ($this->screenCols - $welcomelen) / 2;
+			if ($padding > 0)
+			{
+				$this->outputBuffer .= '~';
+				$padding--;
+			}
+			for ($i = 0; $i < $padding; $i++)
+			{
+				$this->outputBuffer .= ' ';
+			}
+
+			$this->outputBuffer .= substr($welcome, 0, $welcomelen);
+		}
+		else
+		{
+			$this->outputBuffer .= '~';
 		}
 	}
 
 	protected function drawStatusBar(): void
 	{
-		$this->ab .= ANSI::color(Color::INVERT);
+		$this->outputBuffer .= ANSI::color(Color::INVERT);
 
 		$statusFilename = $this->filename !== '' ? $this->filename : '[No Name]';
 		$syntaxType = ($this->syntax !== NULL) ? $this->syntax->filetype : 'no ft';
@@ -632,25 +640,25 @@ class Editor {
 		{
 			$len = $this->screenCols;
 		}
-		$this->ab .= substr($status, 0, $len);
+		$this->outputBuffer .= substr($status, 0, $len);
 		while ($len < $this->screenCols)
 		{
 			if ($this->screenCols - $len === $rlen)
 			{
-				$this->ab .= substr($rstatus, 0, $rlen);
+				$this->outputBuffer .= substr($rstatus, 0, $rlen);
 				break;
 			}
 
-			$this->ab .= ' ';
+			$this->outputBuffer .= ' ';
 			$len++;
 		}
-		$this->ab .= ANSI::RESET_TEXT;
-		$this->ab .= "\r\n";
+		$this->outputBuffer .= ANSI::RESET_TEXT;
+		$this->outputBuffer .= "\r\n";
 	}
 
 	protected function drawMessageBar(): void
 	{
-		$this->ab .= ANSI::CLEAR_LINE;
+		$this->outputBuffer .= ANSI::CLEAR_LINE;
 		$len = strlen($this->statusMsg);
 		if ($len > $this->screenCols)
 		{
@@ -659,7 +667,7 @@ class Editor {
 
 		if ($len > 0 && (time() - $this->statusMsgTime) < 5)
 		{
-			$this->ab .= substr($this->statusMsg, 0, $len);
+			$this->outputBuffer .= substr($this->statusMsg, 0, $len);
 		}
 	}
 
@@ -667,24 +675,24 @@ class Editor {
 	{
 		$this->scroll();
 
-		$this->ab = '';
+		$this->outputBuffer = '';
 
-		$this->ab .= ANSI::HIDE_CURSOR;
-		$this->ab .= ANSI::RESET_CURSOR;
+		$this->outputBuffer .= ANSI::HIDE_CURSOR;
+		$this->outputBuffer .= ANSI::RESET_CURSOR;
 
 		$this->drawRows();
 		$this->drawStatusBar();
 		$this->drawMessageBar();
 
 		// Specify the current cursor position
-		$this->ab .= ANSI::moveCursor(
+		$this->outputBuffer .= ANSI::moveCursor(
 			($this->cursorY - $this->rowOffset) + 1,
 			($this->renderX - $this->colOffset) + 1
 		);
 
-		$this->ab .= ANSI::SHOW_CURSOR;
+		$this->outputBuffer .= ANSI::SHOW_CURSOR;
 
-		echo $this->ab;
+		echo $this->outputBuffer;
 	}
 
 	public function setStatusMessage(string $fmt, mixed ...$args): void
@@ -904,7 +912,7 @@ class Editor {
 	protected function refreshSyntax(): void
 	{
 		// Update the syntax highlighting for all the rows of the file
-		// array_walk($this->rows, static fn (Row $row) => $row->updateSyntax());
+		array_walk($this->rows, static fn (Row $row) => $row->updateSyntax());
 	}
 
 	private function refreshPHPSyntax(): void
diff --git a/src/Enum/Color.php b/src/Enum/Color.php
index 1fe6085..ce11d31 100644
--- a/src/Enum/Color.php
+++ b/src/Enum/Color.php
@@ -6,6 +6,7 @@ use Aviat\Kilo\Traits;
 
 /**
  * ANSI Color escape sequences
+ * @enum
  */
 class Color {
 	use Traits\ConstList;
diff --git a/src/Enum/Highlight.php b/src/Enum/Highlight.php
index ed37fed..48f797e 100644
--- a/src/Enum/Highlight.php
+++ b/src/Enum/Highlight.php
@@ -4,6 +4,9 @@ namespace Aviat\Kilo\Enum;
 
 use Aviat\Kilo\Traits;
 
+/**
+ * @enum
+ */
 class Highlight {
 	use Traits\ConstList;
 
diff --git a/src/Enum/KeyCode.php b/src/Enum/KeyCode.php
index 5fd94df..3d2fdc0 100644
--- a/src/Enum/KeyCode.php
+++ b/src/Enum/KeyCode.php
@@ -7,6 +7,7 @@ use function Aviat\Kilo\ctrl_key;
 
 /**
  * 'Raw' input from stdin
+ * @enum
  */
 class KeyCode {
 	use Traits\ConstList;
@@ -35,7 +36,7 @@ class KeyCode {
 	 * ctrl + letter combo
 	 *
 	 * @param string $char
-	 * @return string
+	 * @return string|null
 	 */
 	public static function CTRL(string $char): ?string
 	{
diff --git a/src/Enum/KeyType.php b/src/Enum/KeyType.php
index ef1fd90..dee5c4e 100644
--- a/src/Enum/KeyType.php
+++ b/src/Enum/KeyType.php
@@ -6,6 +6,7 @@ use Aviat\Kilo\Traits;
 
 /**
  * Constants representing various control keys
+ * @enum
  */
 class KeyType {
 	use Traits\ConstList;
diff --git a/src/Event.php b/src/Event.php
index 55d5fce..6c9f9af 100644
--- a/src/Event.php
+++ b/src/Event.php
@@ -14,9 +14,9 @@ class Event {
 	public const QUIT_ATTEMPT = 'QUIT_ATTEMPT';
 
 	// Mapping of events to handlers
-	private static $subscribeMap = [];
+	private static array $subscribeMap = [];
 
-	public static function fire(string $eventName, $value): void
+	public static function fire(string $eventName, mixed $value): void
 	{
 		static::validateEvent($eventName);
 
diff --git a/src/Row.php b/src/Row.php
index f502f1e..1acb919 100644
--- a/src/Row.php
+++ b/src/Row.php
@@ -8,6 +8,7 @@ use Aviat\Kilo\Enum\KeyCode;
 /**
  * @property-read int $size
  * @property-read int $rsize
+ * @property-read string $chars
  */
 class Row {
 	use Traits\MagicProperties;
diff --git a/src/Traits/MagicProperties.php b/src/Traits/MagicProperties.php
index 6cde0fd..92661a8 100644
--- a/src/Traits/MagicProperties.php
+++ b/src/Traits/MagicProperties.php
@@ -5,7 +5,7 @@ namespace Aviat\Kilo\Traits;
 trait MagicProperties {
 	abstract public function __get(string $name);
 
-	public function __set(string $name, $value)
+	public function __set(string $name, mixed $value): void
 	{
 		if (property_exists($this, $name))
 		{
diff --git a/src/functions.php b/src/functions.php
index 39463a9..6536f88 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -289,10 +289,10 @@ function syntax_to_color(int $hl): int
  * Replace tabs with the specified number of spaces.
  *
  * @param string $str
- * @param int|null $number
+ * @param int $number
  * @return string
  */
-function tabs_to_spaces(string $str, ?int $number = KILO_TAB_STOP): string
+function tabs_to_spaces(string $str, int $number = KILO_TAB_STOP): string
 {
 	return str_replace(KeyCode::TAB, str_repeat(KeyCode::SPACE, $number), $str);
 }
@@ -629,6 +629,7 @@ function php_token_to_highlight(int $token): int
 
 		// Invalid syntax
 		T_BAD_CHARACTER => Highlight::INVALID,
+
 		default => Highlight::NORMAL,
 	};
 }