trace.php

<?php
function argToString($arg, $maxLength = false) {
    if (is_null($arg)) {
        return 'null';
    } elseif (is_array($arg)) {
        return 'Array';
    } elseif (is_object($arg)) {
        return 'Object(' . get_class($arg) . ')';
    } elseif (is_bool($arg)) {
        return $arg ? 'true' : 'false';
    } elseif (is_int($arg) || is_double($arg)) {
        return $arg;
    } else {
        $arg = (string) $arg;
        if ($maxLength && strlen($arg) > $maxLength ) {
            $arg = substr($arg, 0, $maxLength) . '...';
        }
        return "'" . $arg . "'";
    }
}

function traceToString($trace) {
    $trace = array_reverse($trace); // Show in reverse order
    $len = count($trace);
    $result = '';
    foreach($trace as $i => $t) {
        $result .= '#' . ($len - $i - 1) . ' ';
        if (!empty($t['class'])) {
            $result .= $t['class'] . $t['type'];
        }
        $result .= $t['function'];
        $args = array();
        if (!empty($t['args'])) {
            foreach ($t['args'] as $arg) {
                $args[] = argToString($arg);
            }
        }
        $result .= '(' . implode(', ', $args) . ') at '
            . (isset($t['file']) ? $t['file'] : 'Unknown')
            . ':' . (isset($t['line']) ? $t['line'] : 'Unknown')
            . "\n";
    }
    return $result;
}