Extract namespace from a PHP file

compare.php

<?php

// Works in every situations
function by_token ($src) {
	$tokens = token_get_all($src);
	$count = count($tokens);
	$i = 0;
	$namespace = '';
	$namespace_ok = false;
	while ($i < $count) {
		$token = $tokens[$i];
		if (is_array($token) && $token[0] === T_NAMESPACE) {
			// Found namespace declaration
			while (++$i < $count) {
				if ($tokens[$i] === ';') {
					$namespace_ok = true;
					$namespace = trim($namespace);
					break;
				}
				$namespace .= is_array($tokens[$i]) ? $tokens[$i][1] : $tokens[$i];
			}
			break;
		}
		$i++;
	}

	if (!$namespace_ok) {
		return null;
	} else {
		return $namespace;
	}
}

// Makes many assumptions on file format:
// namespace is declared on its own line, starting with "namespace" (no spaces).
function by_regexp($src) {
	if (preg_match('#^namespace\s+(.+?);$#sm', $src, $m)) {
		return $m[1];
	}
	return null;
}

function bench($foo, $src) {
	$start = microtime(true);
	for ($i=0; $i<10000; $i++) {
		$ns = $foo($src);
		if ($ns !== 'Acme\\HelloBundle\\DependencyInjection') {
			throw new Exception('Mother fucker ?');
		}
	}
	$end = microtime(true);
	return $end - $start;
}



$src = file_get_contents("/path/to/file.php");
var_dump(bench('by_token', $src), bench('by_regexp', $src));
// Result on my machine for "Acme\HelloBundle\DependencyInjection":
// float(1.6613008975983)
// float(0.1151180267334)

I use this matching method to prevent false positives

    if (preg_match('#(namespace)(\\s+)([A-Za-z0-9\\\\]+?)(\\s*);#sm', $line, $m)) {
        return $m[3];
    }
    return null;

example of false positive is

  echo "The namespace is defined as a Foo\Bar\Baz";