Pipeline.php

<?php
    class Pipeline
    {
        public static function make_pipeline()
        {
            $func_list = func_get_args();
            
            $result = function($arg) use ($func_list)
            {
                foreach($func_list as $funcs)
                {
                    if(!isset($value))
                    {
                        echo "set value!\n";
                        $value  =   $funcs($arg);
                    }
                    else
                    {
                        echo "update value!\n";
                        $value  =   $funcs($value);
                    }
                    
                    echo "Argument $value is: " . $value . "\n";
                }
                return $value;
            };
            
            return $result;
        }
    }
    $fun = Pipeline::make_pipeline(function($x) { return $x * 3; }, function($x) { return $x + 1; },
                              function($x) { return $x / 2; });
    echo $fun(3); # should print 5
?>