Small improvements on "boot.php"

- Avoid using `else`;
- Create an exception handler;
- Exists when a ROM is not defined.

1 files changed, 20 insertions, 13 deletions

diff --git a/boot.php b/boot.php
index bba0021..292e90f 100644
--- a/boot.php
+++ b/boot.php
@@ -6,8 +6,13 @@ use GameBoy\Canvas\TerminalCanvas;
 use GameBoy\Core;
 use GameBoy\Keyboard;
 
+set_exception_handler(function (Exception $exception) {
+    fwrite(STDERR, $exception->getMessage().PHP_EOL);
+    exit(254);
+});
+
 if (count($argv) < 2) {
-    echo 'You need to pass the ROM file name (Ex: drmario.rom)';
+    throw new RuntimeException('You need to pass the ROM file name (Ex: drmario.rom)');
 }
 
 $rom = base64_decode(file_get_contents($argv[1]));
@@ -18,16 +23,18 @@ $keyboard = new Keyboard($core);
 
 $core->start();
 
-if ($core->stopEmulator & 2 == 2) {
-    $core->stopEmulator &= 1;
-    $core->lastIteration = (int) (microtime(true) * 1000);
-
-    while (true) {
-        $core->run();
-        $keyboard->check();
-    }
-} else if (($core->stopEmulator & 2) == 0) {
-    echo 'The GameBoy core is already running.' . PHP_EOL;
-} else {
-    echo 'GameBoy core cannot run while it has not been initialized.' . PHP_EOL;
+if (($core->stopEmulator & 2) == 0) {
+    throw new RuntimeException('The GameBoy core is already running.');
+}
+
+if ($core->stopEmulator & 2 != 2) {
+    throw new RuntimeException('GameBoy core cannot run while it has not been initialized.');
+}
+
+$core->stopEmulator &= 1;
+$core->lastIteration = (int) (microtime(true) * 1000);
+
+while (true) {
+    $core->run();
+    $keyboard->check();
 }