diff --git a/Dockerfile b/Dockerfile
index 87c8ff9..944d4de 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:8-alpine3.13
+FROM php:alpine
 
 RUN apk add --no-cache --virtual .persistent-deps libffi-dev \
     && docker-php-ext-configure ffi --with-ffi \
diff --git a/Jenkinsfile b/Jenkinsfile
index 4914f22..f95f8cc 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -5,7 +5,7 @@ pipeline {
  		}
  	}
  	stages {
- 		stage('PHP 7.4') {
+ 		stage('PHP 8.1') {
  			steps {
  				sh 'apk add --no-cache -X http://dl-cdn.alpinelinux.org/alpine/edge/testing php8-phpdbg'
  				sh 'curl -sS https://getcomposer.org/installer | php'
diff --git a/src/ANSI.php b/src/ANSI.php
index 3f82d15..a75b71c 100644
--- a/src/ANSI.php
+++ b/src/ANSI.php
@@ -58,12 +58,12 @@ class ANSI {
 	/**
 	 * Generate the ascii sequence for basic foreground text color
 	 *
-	 * @param int $color
+	 * @param Enum\Color $color
 	 * @return string
 	 */
-	public static function color(int $color): string
+	public static function color(Enum\Color $color): string
 	{
-		return self::escapeSequence('%dm', $color);
+		return self::escapeSequence('%dm', $color->value);
 	}
 
 	/**
diff --git a/src/Document.php b/src/Document.php
index b0c5167..2c8cf91 100644
--- a/src/Document.php
+++ b/src/Document.php
@@ -95,14 +95,14 @@ class Document {
 		return $res;
 	}
 
-	public function insert(Point $at, string $c): void
+	public function insert(Point $at, string|KeyType $c): void
 	{
 		if ($at->y > $this->numRows)
 		{
 			return;
 		}
 
-		if ($c === KeyType::ENTER || $c === RawKeyCode::CARRIAGE_RETURN)
+		if ($c === KeyType::Enter || $c === RawKeyCode::CARRIAGE_RETURN)
 		{
 			$this->insertNewline($at);
 			$this->dirty = true;
diff --git a/src/Editor.php b/src/Editor.php
index d9435e3..3204c7a 100644
--- a/src/Editor.php
+++ b/src/Editor.php
@@ -233,7 +233,7 @@ class Editor {
 	// ! Find
 	// ------------------------------------------------------------------------
 
-	protected function findCallback(string $query, string $key): void
+	protected function findCallback(string $query, string|KeyType $key): void
 	{
 		static $lastMatch = NO_MATCH;
 		static $direction = SearchDirection::FORWARD;
@@ -254,11 +254,11 @@ class Editor {
 		}
 
 		$direction = match ($key) {
-			KeyType::ARROW_UP, KeyType::ARROW_LEFT => SearchDirection::BACKWARD,
+			KeyType::ArrowUp, KeyType::ArrowLeft => SearchDirection::BACKWARD,
 			default => SearchDirection::FORWARD
 		};
 
-		$arrowKeys = [KeyType::ARROW_UP, KeyType::ARROW_DOWN, KeyType::ARROW_LEFT, KeyType::ARROW_RIGHT];
+		$arrowKeys = [KeyType::ArrowUp, KeyType::ArrowDown, KeyType::ArrowLeft, KeyType::ArrowRight];
 
 		// Reset search state with non arrow-key input
 		if ( ! in_array($key, $arrowKeys, true))
@@ -286,7 +286,7 @@ class Editor {
 
 		for ($i = 0; $i < $this->document->numRows; $i++)
 		{
-			$current += $direction;
+			$current += $direction->value;
 			if ($current === -1)
 			{
 				$current = $this->document->numRows - 1;
@@ -313,7 +313,7 @@ class Editor {
 				$savedHlLine = $current;
 				$savedHl = $row->hl;
 				// Update the highlight array of the relevant row with the 'MATCH' type
-				array_replace_range($row->hl, $match, strlen($query), Highlight::MATCH);
+				array_replace_range($row->hl, $match, strlen($query), Highlight::SearchMatch);
 
 				break;
 			}
@@ -432,7 +432,7 @@ class Editor {
 					$this->outputBuffer .= ANSI::color($currentColor);
 				}
 			}
-			else if ($hl[$i] === Highlight::NORMAL)
+			else if ($hl[$i] === Highlight::Normal)
 			{
 				if ($currentColor !== -1)
 				{
@@ -574,7 +574,7 @@ class Editor {
 			$c = Terminal::readKey();
 			$isModifier = in_array($c, $modifiers, TRUE);
 
-			if ($c === KeyType::ESCAPE || ($c === RawKeyCode::ENTER && $buffer !== ''))
+			if ($c === KeyType::Escape || ($c === RawKeyCode::ENTER && $buffer !== ''))
 			{
 				$this->setStatusMessage('');
 				if ($callback !== NULL)
@@ -584,7 +584,7 @@ class Editor {
 				return ($c === RawKeyCode::ENTER) ? $buffer : '';
 			}
 
-			if ($c === KeyType::DELETE || $c === KeyType::BACKSPACE)
+			if ($c === KeyType::Delete || $c === KeyType::Backspace)
 			{
 				$buffer = substr($buffer, 0, -1);
 			}
@@ -618,32 +618,32 @@ class Editor {
 				$this->quitAttempt();
 				return;
 
-			case RawKeyCode::CTRL('s'):
-				$this->save();
-			break;
+				case RawKeyCode::CTRL('s'):
+					$this->save();
+				break;
 
-			case RawKeyCode::CTRL('f'):
-				$this->find();
-			break;
+				case RawKeyCode::CTRL('f'):
+					$this->find();
+				break;
 
-			case KeyType::DELETE:
-			case KeyType::BACKSPACE:
+			case KeyType::Delete:
+			case KeyType::Backspace:
 				$this->removeChar($c);
 			break;
 
-			case KeyType::ARROW_UP:
-			case KeyType::ARROW_DOWN:
-			case KeyType::ARROW_LEFT:
-			case KeyType::ARROW_RIGHT:
-			case KeyType::PAGE_UP:
-			case KeyType::PAGE_DOWN:
-			case KeyType::HOME:
-			case KeyType::END:
+			case KeyType::ArrowUp:
+			case KeyType::ArrowDown:
+			case KeyType::ArrowLeft:
+			case KeyType::ArrowRight:
+			case KeyType::PageUp:
+			case KeyType::PageDown:
+			case KeyType::Home:
+			case KeyType::End:
 				$this->moveCursor($c);
 			break;
 
 			case RawKeyCode::CTRL('l'):
-			case KeyType::ESCAPE:
+			case KeyType::Escape:
 				// Do nothing
 			break;
 
@@ -664,7 +664,7 @@ class Editor {
 	// ! Editor operation helpers
 	// ------------------------------------------------------------------------
 
-	protected function moveCursor(string $key): void
+	protected function moveCursor(KeyType $key): void
 	{
 		$x = $this->cursor->x;
 		$y = $this->cursor->y;
@@ -676,7 +676,7 @@ class Editor {
 
 		switch ($key)
 		{
-			case KeyType::ARROW_LEFT:
+			case KeyType::ArrowLeft:
 				if ($x !== 0)
 				{
 					$x--;
@@ -689,7 +689,7 @@ class Editor {
 				}
 				break;
 
-			case KeyType::ARROW_RIGHT:
+			case KeyType::ArrowRight:
 				if ($x < $row->size)
 				{
 					$x++;
@@ -701,33 +701,33 @@ class Editor {
 				}
 				break;
 
-			case KeyType::ARROW_UP:
+			case KeyType::ArrowUp:
 				if ($y !== 0)
 				{
 					$y--;
 				}
 				break;
 
-			case KeyType::ARROW_DOWN:
+			case KeyType::ArrowDown:
 				if ($y < $this->document->numRows)
 				{
 					$y++;
 				}
 				break;
 
-			case KeyType::PAGE_UP:
+			case KeyType::PageUp:
 				$y = saturating_sub($y, $this->terminalSize->rows);
 				break;
 
-			case KeyType::PAGE_DOWN:
+			case KeyType::PageDown:
 				$y = saturating_add($y, $this->terminalSize->rows, $this->document->numRows);
 				break;
 
-			case KeyType::HOME:
+			case KeyType::Home:
 				$x = 0;
 				break;
 
-			case KeyType::END:
+			case KeyType::End:
 				if ($y < $this->document->numRows)
 				{
 					$x = $row->size;
@@ -753,22 +753,22 @@ class Editor {
 		}
 	}
 
-	protected function insertChar(string $c): void
+	protected function insertChar(string|KeyType $c): void
 	{
 		$this->document->insert($this->cursor, $c);
-		$this->moveCursor(KeyType::ARROW_RIGHT);
+		$this->moveCursor(KeyType::ArrowRight);
 	}
 
-	protected function removeChar(string $ch): void
+	protected function removeChar(string|KeyType $ch): void
 	{
-		if ($ch === KeyType::DELETE)
+		if ($ch === KeyType::Delete)
 		{
 			$this->document->delete($this->cursor);
 		}
 
-		if ($ch === KeyType::BACKSPACE && ($this->cursor->x > 0 || $this->cursor->y > 0))
+		if ($ch === KeyType::Backspace && ($this->cursor->x > 0 || $this->cursor->y > 0))
 		{
-			$this->moveCursor(KeyType::ARROW_LEFT);
+			$this->moveCursor(KeyType::ArrowLeft);
 			$this->document->delete($this->cursor);
 		}
 	}
diff --git a/src/Row.php b/src/Row.php
index b3c29d5..c280d37 100644
--- a/src/Row.php
+++ b/src/Row.php
@@ -197,7 +197,7 @@ class Row {
 	 */
 	public function highlight(): void
 	{
-		$this->hl = array_fill(0, $this->rsize, Highlight::NORMAL);
+		$this->hl = array_fill(0, $this->rsize, Highlight::Normal);
 
 		if ($this->parent->fileType->name === 'PHP')
 		{
@@ -230,10 +230,10 @@ class Row {
 			{
 				if ($inComment)
 				{
-					$this->hl[$i] = Highlight::ML_COMMENT;
+					$this->hl[$i] = Highlight::MultiLineComment;
 					if (substr($this->render, $i, $mceLen) === $mce)
 					{
-						array_replace_range($this->hl, $i, $mceLen, Highlight::ML_COMMENT);
+						array_replace_range($this->hl, $i, $mceLen, Highlight::MultiLineComment);
 						$i += $mceLen;
 						$inComment = FALSE;
 						continue;
@@ -245,7 +245,7 @@ class Row {
 
 				if (substr($this->render, $i, $mcsLen) === $mcs)
 				{
-					array_replace_range($this->hl, $i, $mcsLen, Highlight::ML_COMMENT);
+					array_replace_range($this->hl, $i, $mcsLen, Highlight::MultiLineComment);
 					$i += $mcsLen;
 					$inComment = TRUE;
 					continue;
@@ -287,7 +287,7 @@ class Row {
 	protected function highlightNumber(int &$i, Syntax $opts): bool
 	{
 		$char = $this->render[$i];
-		if ($opts->numbers() && is_digit($char) && $this->hl[$i] === Highlight::NORMAL)
+		if ($opts->numbers() && is_digit($char) && $this->hl[$i] === Highlight::Normal)
 		{
 			if ($i > 0)
 			{
@@ -300,7 +300,7 @@ class Row {
 
 			while (true)
 			{
-				$this->hl[$i] = Highlight::NUMBER;
+				$this->hl[$i] = Highlight::Number;
 				$i++;
 
 				if ($i < strlen($this->render))
@@ -326,11 +326,11 @@ class Row {
 	 *
 	 * @param int $i
 	 * @param array $keywords
-	 * @param int $syntaxType
+	 * @param Highlight $syntaxType
 	 * @param bool $requireSeparator
 	 * @return bool
 	 */
-	protected function highlightWord(int &$i, array $keywords, int $syntaxType, bool $requireSeparator = true): bool
+	protected function highlightWord(int &$i, array $keywords, Highlight $syntaxType, bool $requireSeparator = true): bool
 	{
 		if ($i > 0 && $requireSeparator)
 		{
@@ -365,12 +365,12 @@ class Row {
 	 *
 	 * @param int $i
 	 * @param array $chars
-	 * @param int $syntaxType
+	 * @param Highlight $syntaxType
 	 * @return bool
 	 */
-	protected function highlightChar(int &$i, array $chars, int $syntaxType): bool
+	protected function highlightChar(int &$i, array $chars, Highlight $syntaxType): bool
 	{
-		if ($this->hl[$i] !== Highlight::NORMAL)
+		if ($this->hl[$i] !== Highlight::Normal)
 		{
 			return false;
 		}
@@ -397,7 +397,7 @@ class Row {
 	 */
 	protected function highlightPrimaryKeywords(int &$i, Syntax $opts): bool
 	{
-		return $this->highlightWord($i, $opts->keywords1, Highlight::KEYWORD1);
+		return $this->highlightWord($i, $opts->keywords1, Highlight::Keyword1);
 	}
 
 	/**
@@ -409,7 +409,7 @@ class Row {
 	 */
 	protected function highlightSecondaryKeywords(int &$i, Syntax $opts): bool
 	{
-		return $this->highlightWord($i, $opts->keywords2, Highlight::KEYWORD2);
+		return $this->highlightWord($i, $opts->keywords2, Highlight::Keyword2);
 	}
 
 	/**
@@ -421,7 +421,7 @@ class Row {
 	 */
 	protected function highlightOperators(int &$i, Syntax $opts): bool
 	{
-		return $this->highlightWord($i, $opts->operators, Highlight::OPERATOR, false);
+		return $this->highlightWord($i, $opts->operators, Highlight::Operator, false);
 	}
 
 	/**
@@ -441,7 +441,7 @@ class Row {
 		return $this->highlightChar(
 			$i,
 			['+', '-', '*', '/', '<', '^', '>', '%', '=', ':', ',', ';', '&', '~', '!', '|', '.'],
-			Highlight::OPERATOR
+			Highlight::Operator
 		);
 	}
 
@@ -456,7 +456,7 @@ class Row {
 		return $this->highlightChar(
 			$i,
 			['{', '}', '[', ']', '(', ')'],
-			Highlight::DELIMITER
+			Highlight::Delimiter
 		);
 	}
 
@@ -489,7 +489,7 @@ class Row {
 			$closingChar = $this->render[$closingIndex];
 			if ($closingChar === "'")
 			{
-				array_replace_range($this->hl, $i, $closingIndex - $i + 1, Highlight::CHARACTER);
+				array_replace_range($this->hl, $i, $closingIndex - $i + 1, Highlight::Character);
 				$i = $closingIndex + 1;
 
 				return true;
@@ -518,7 +518,7 @@ class Row {
 
 		if ($scsLen > 0 && substr($this->render, $i, $scsLen) === $scs)
 		{
-			array_replace_range($this->hl, $i, $this->rsize - $i, Highlight::COMMENT);
+			array_replace_range($this->hl, $i, $this->rsize - $i, Highlight::Comment);
 			$i = $this->rsize;
 
 			return true;
@@ -547,18 +547,18 @@ class Row {
 		if ($opts->strings() && ($char === '"' || $char === '\''))
 		{
 			$quote = $char;
-			$this->hl[$i] = Highlight::STRING;
+			$this->hl[$i] = Highlight::String;
 			$i++;
 
 			while ($i < $this->rsize)
 			{
 				$char = $this->render[$i];
-				$this->hl[$i] = Highlight::STRING;
+				$this->hl[$i] = Highlight::String;
 
 				// Check for escaped character
 				if ($char === '\\' && $i+1 < $this->rsize)
 				{
-					$this->hl[$i + 1] = Highlight::STRING;
+					$this->hl[$i + 1] = Highlight::String;
 					$i += 2;
 					continue;
 				}
@@ -617,14 +617,14 @@ class Row {
 				if ($commentEnd !== FALSE)
 				{
 					$inComment = FALSE;
-					array_replace_range($this->hl, 0, $commentEnd + 2, Highlight::ML_COMMENT);
+					array_replace_range($this->hl, 0, $commentEnd + 2, Highlight::MultiLineComment);
 					$offset = $commentEnd;
 					continue;
 				}
 
 				// Otherwise, just set the whole row
-				$this->hl = array_fill(0, $this->rsize, Highlight::ML_COMMENT);
-				$this->hl[$offset] = Highlight::ML_COMMENT;
+				$this->hl = array_fill(0, $this->rsize, Highlight::MultiLineComment);
+				$this->hl[$offset] = Highlight::MultiLineComment;
 				break;
 			}
 
@@ -647,7 +647,7 @@ class Row {
 				// Single line comments
 				if (str_contains($char, '//') || str_contains($char, '#'))
 				{
-					array_replace_range($this->hl, $charStart, $charLen, Highlight::COMMENT);
+					array_replace_range($this->hl, $charStart, $charLen, Highlight::Comment);
 					break;
 				}
 
@@ -662,13 +662,13 @@ class Row {
 					if ($hasEnd)
 					{
 						$len = $end - $start + 2;
-						array_replace_range($this->hl, $start, $len, Highlight::ML_COMMENT);
+						array_replace_range($this->hl, $start, $len, Highlight::MultiLineComment);
 						$inComment = FALSE;
 					}
 					else
 					{
 						$inComment = TRUE;
-						array_replace_range($this->hl, $start, $charLen - $offset, Highlight::ML_COMMENT);
+						array_replace_range($this->hl, $start, $charLen - $offset, Highlight::MultiLineComment);
 						$offset = $start + $charLen - $offset;
 					}
 				}
@@ -684,16 +684,16 @@ class Row {
 
 			$highlight = match(true) {
 				// Matches a predefined PHP token
-				$token['type'] !== T_RAW && $tokenHighlight !== Highlight::NORMAL
+				$token['type'] !== T_RAW && $tokenHighlight !== Highlight::Normal
 				=> $tokenHighlight,
 
 				// Matches a specific syntax character
-				$charHighlight !== Highlight::NORMAL => $charHighlight,
+				$charHighlight !== Highlight::Normal => $charHighlight,
 
-				default => Highlight::NORMAL,
+				default => Highlight::Normal,
 			};
 
-			if ($highlight !== Highlight::NORMAL)
+			if ($highlight !== Highlight::Normal)
 			{
 				array_replace_range($this->hl, $charStart, $charLen, $highlight);
 				$offset = $charEnd;
diff --git a/src/Syntax.php b/src/Syntax.php
index 76986f7..48b4a62 100644
--- a/src/Syntax.php
+++ b/src/Syntax.php
@@ -22,7 +22,7 @@ class Syntax {
 		bool $hasCharType = false,
 		bool $highlightCharacters = false,
 		bool $hasCommonOperators = true,
-		string $syntaxFamily = SyntaxFamily::C,
+		SyntaxFamily $syntaxFamily = SyntaxFamily::C,
 	): self
 	{
 		return new self(
@@ -84,7 +84,7 @@ class Syntax {
 		/** should we highlight common operators? */
 		private bool $hasCommonOperators,
 		/** What kind of general syntax family does this file belong to? */
-		private string $syntaxFamily,
+		private SyntaxFamily $syntaxFamily,
 	) {}
 
 	public function numbers(): bool
@@ -124,7 +124,7 @@ class Syntax {
 		return $this->hasCommonOperators;
 	}
 
-	public function syntaxFamily(): string
+	public function syntaxFamily(): SyntaxFamily
 	{
 		return $this->syntaxFamily;
 	}
diff --git a/src/Terminal.php b/src/Terminal.php
index b6e85ff..7aad71d 100644
--- a/src/Terminal.php
+++ b/src/Terminal.php
@@ -81,35 +81,35 @@ class Terminal {
 	 * Get the last key input from the terminal and convert to a
 	 * more useful format
 	 *
-	 * @return string
+	 * @return string|KeyType
 	 */
-	public static function readKey(): string
+	public static function readKey(): string|KeyType
 	{
 		$c = Terminal::read();
 
 		return match($c)
 		{
 			// Unambiguous mappings
-			RawKeyCode::ARROW_DOWN => KeyType::ARROW_DOWN,
-			RawKeyCode::ARROW_LEFT => KeyType::ARROW_LEFT,
-			RawKeyCode::ARROW_RIGHT => KeyType::ARROW_RIGHT,
-			RawKeyCode::ARROW_UP => KeyType::ARROW_UP,
-			RawKeyCode::DELETE => KeyType::DELETE,
-			RawKeyCode::ENTER => KeyType::ENTER,
-			RawKeyCode::PAGE_DOWN => KeyType::PAGE_DOWN,
-			RawKeyCode::PAGE_UP => KeyType::PAGE_UP,
+			RawKeyCode::ARROW_DOWN => KeyType::ArrowDown,
+			RawKeyCode::ARROW_LEFT => KeyType::ArrowLeft,
+			RawKeyCode::ARROW_RIGHT => KeyType::ArrowRight,
+			RawKeyCode::ARROW_UP => KeyType::ArrowUp,
+			RawKeyCode::DELETE => KeyType::Delete,
+			RawKeyCode::ENTER => KeyType::Enter,
+			RawKeyCode::PAGE_DOWN => KeyType::PageDown,
+			RawKeyCode::PAGE_UP => KeyType::PageUp,
 
 			// Backspace
-			RawKeyCode::CTRL('h'), RawKeyCode::BACKSPACE => KeyType::BACKSPACE,
+			RawKeyCode::CTRL('h'), RawKeyCode::BACKSPACE => KeyType::Backspace,
 
 			// Escape
-			RawKeyCode::CTRL('l'), RawKeyCode::ESCAPE => KeyType::ESCAPE,
+			RawKeyCode::CTRL('l'), RawKeyCode::ESCAPE => KeyType::Escape,
 
 			// Home Key
-			"\eOH", "\e[7~", "\e[1~", ANSI::RESET_CURSOR => KeyType::HOME,
+			"\eOH", "\e[7~", "\e[1~", ANSI::RESET_CURSOR => KeyType::Home,
 
 			// End Key
-			"\eOF", "\e[4~", "\e[8~", "\e[F" => KeyType::END,
+			"\eOF", "\e[4~", "\e[8~", "\e[F" => KeyType::End,
 
 			default => $c,
 		};
diff --git a/src/config.php b/src/config.php
index 2896449..d7fd54b 100644
--- a/src/config.php
+++ b/src/config.php
@@ -8,25 +8,25 @@ use Aviat\Kilo\Enum\Highlight;
 /**
  * Configure syntax highlighting colors
  *
- * @param int $hl
- * @return int
+ * @param Highlight $hl
+ * @return Color
  */
-function get_syntax_color(int $hl): int {
+function get_syntax_color(Highlight $hl): Color {
 	return match ($hl)
 	{
-		Highlight::COMMENT => Color::FG_CYAN,
-		Highlight::ML_COMMENT => Color::FG_BRIGHT_BLACK,
-		Highlight::KEYWORD1 => Color::FG_YELLOW,
-		Highlight::KEYWORD2 => Color::FG_GREEN,
-		Highlight::STRING => Color::FG_MAGENTA,
-		Highlight::CHARACTER => Color::FG_BRIGHT_MAGENTA,
-		Highlight::NUMBER => Color::FG_BRIGHT_RED,
-		Highlight::OPERATOR => Color::FG_BRIGHT_GREEN,
-		Highlight::VARIABLE => Color::FG_BRIGHT_CYAN,
-		Highlight::DELIMITER => Color::FG_BLUE,
-		Highlight::INVALID => Color::BG_BRIGHT_RED,
-		Highlight::MATCH => Color::INVERT,
-		Highlight::IDENTIFIER => Color::FG_BRIGHT_WHITE,
+		Highlight::Comment => Color::FG_CYAN,
+		Highlight::MultiLineComment => Color::FG_BRIGHT_BLACK,
+		Highlight::Keyword1 => Color::FG_YELLOW,
+		Highlight::Keyword2 => Color::FG_GREEN,
+		Highlight::String => Color::FG_MAGENTA,
+		Highlight::Character => Color::FG_BRIGHT_MAGENTA,
+		Highlight::Number => Color::FG_BRIGHT_RED,
+		Highlight::Operator => Color::FG_BRIGHT_GREEN,
+		Highlight::Variable => Color::FG_BRIGHT_CYAN,
+		Highlight::Delimiter => Color::FG_BLUE,
+		Highlight::Invalid => Color::BG_BRIGHT_RED,
+		Highlight::SearchMatch => Color::INVERT,
+		Highlight::Identifier => Color::FG_BRIGHT_WHITE,
 		default => Color::FG_WHITE,
 	};
 }
\ No newline at end of file