compress.php

<?php

use PhpParser\Node;

$IN_DIR  = __DIR__ . '/in_dir';
$OUT_FILE = __DIR__ . '/out_file.php';

require __DIR__ . '/../lib/bootstrap.php';

class CompressVisitor extends PhpParser\NodeVisitorAbstract {
    public function leaveNode(Node $node) {
        if ($node instanceof Node\Stmt\Use_) {
            return false;
        }
    }
}

$parser        = new PhpParser\Parser(new PhpParser\Lexer\Emulative);
$traverser     = new PhpParser\NodeTraverser;
$prettyPrinter = new PhpParser\PrettyPrinter\Standard;

$traverser->addVisitor(new PhpParser\NodeVisitor\NameResolver);
$traverser->addVisitor(new CompressVisitor);

// iterate over all .php files in the directory
$files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($IN_DIR));
$files = new RegexIterator($files, '/\.php$/');

$allStmts = [];
foreach ($files as $file) {
    try {
        $code = file_get_contents($file);
        $stmts = $parser->parse($code);
        $stmts = $traverser->traverse($stmts);
        $allStmts = array_merge($allStmts, $stmts);
    } catch (PhpParser\Error $e) {
        die('Parse Error: ' . $e->getMessage());
    }
}

file_put_contents($OUT_FILE, $prettyPrinter->prettyPrintFile($allStmts));