1<?php declare(strict_types=1); 2 3namespace PhpParser\Lexer\TokenEmulator; 4 5use PhpParser\Lexer\Emulative; 6 7final class CoaleseEqualTokenEmulator implements TokenEmulatorInterface 8{ 9 public function isEmulationNeeded(string $code) : bool 10 { 11 // skip version where this is supported 12 if (version_compare(\PHP_VERSION, Emulative::PHP_7_4, '>=')) { 13 return false; 14 } 15 16 return strpos($code, '??=') !== false; 17 } 18 19 public function emulate(string $code, array $tokens): array 20 { 21 // We need to manually iterate and manage a count because we'll change 22 // the tokens array on the way 23 $line = 1; 24 for ($i = 0, $c = count($tokens); $i < $c; ++$i) { 25 if (isset($tokens[$i + 1])) { 26 if ($tokens[$i][0] === T_COALESCE && $tokens[$i + 1] === '=') { 27 array_splice($tokens, $i, 2, [ 28 [Emulative::T_COALESCE_EQUAL, '??=', $line] 29 ]); 30 $c--; 31 continue; 32 } 33 } 34 if (\is_array($tokens[$i])) { 35 $line += substr_count($tokens[$i][1], "\n"); 36 } 37 } 38 39 return $tokens; 40 } 41} 42