Use Null Coalesce Operator

src/DiagnosticsProvider.php

@@ -33,9 +33,8 @@ class DiagnosticsProvider {
             return new Diagnostic(
                 DiagnosticKind::Error,
                 "Unexpected '" .
-                (isset(self::$tokenKindToText[$node->kind])
-                    ? self::$tokenKindToText[$node->kind]
-                    : Token::getTokenKindNameFromValue($node->kind)) .
+                (self::$tokenKindToText[$node->kind]
+                    ?? Token::getTokenKindNameFromValue($node->kind)) .
                 "'",
                 $node->start,
                 $node->getEndPosition() - $node->start
@@ -44,9 +43,8 @@ class DiagnosticsProvider {
             return new Diagnostic(
                 DiagnosticKind::Error,
                 "'" .
-                (isset(self::$tokenKindToText[$node->kind])
-                    ? self::$tokenKindToText[$node->kind]
-                    : Token::getTokenKindNameFromValue($node->kind)) .
+                (self::$tokenKindToText[$node->kind]
+                    ?? Token::getTokenKindNameFromValue($node->kind)) .
                 "' expected.",
                 $node->start,
                 $node->getEndPosition() - $node->start

src/PhpTokenizer.php

@@ -107,9 +107,7 @@ class PhpTokenizer implements TokenStreamProviderInterface {
                         continue;
                     }
 
-                    $newTokenKind = isset(self::TOKEN_MAP[$tokenKind])
-                        ? self::TOKEN_MAP[$tokenKind]
-                        : $newTokenKind = TokenKind::Unknown;
+                    $newTokenKind = self::TOKEN_MAP[$tokenKind] ?? TokenKind::Unknown;
                     $arr[] = new Token($newTokenKind, $fullStart, $start, $pos - $fullStart);
                     $start = $fullStart = $pos;
                     continue;