<?php

use Psr\Log\{AbstractLogger, LoggerInterface, LoggerAwareInterface};

$logger = new class() extends AbstractLogger {
    public function log($level, $message, array $context = array())
    {
        $msg = sprintf('[%s] %s', $level, $message);
        
        if ($context) {
            $search = array_keys($context);
            array_walk($search, function(&$value, $key) {
                $value = sprintf('{%s}', $value);
            });
            $replace = array_values($context);
        
            $msg = str_replace($search, $replace, $msg);
        }
        
        echo $msg . PHP_EOL;
    }
};

$object = new class() implements LoggerAwareInterface {
    private $logger;
    
    public function setLogger(LoggerInterface $logger)
    {
        $this->logger = $logger;
    }
    
    public function run()
    {
        if (null !== $this->logger) {
            $this->logger->error('an error happened in {file}', array('file' => 'foo.php'));
            $this->logger->notice('{reason} happened, but I work anyway', array('reason' => 'stuff'));
        }
        
        return 0;
    }
};

$object->setLogger($logger);
$object->run();

[error] an error happened in foo.php
[notice] stuff happened, but I work anyway

• Text-Encoding with intl UConverter
• Create an instance without calling constructor of the class
• Introduced in PHP 7: call-method of closures

PHP 8.3, Laminas MVC 3.2, Symfony 5.2, Laravel 8.28, PHPUnit 9.5, Doctrine ORM 2.8