brainfuck.php

<?php
// Your code here!

class Switcher {
    public static $calls = [];
    public static function register($case, Closure $callback){
        self::$calls[$case] = new Executor($callback);
    }
    
    public static function onCase($case){
        return isset(self::$calls[$case]) ? self::$calls[$case] : new Executor(function(){});
    }
}

class Executor {
    public function __construct(Closure $callback){
        $this->callback = $callback;
    }
    public function call(...$args){
        $callback = $this->getCallBack();
        return call_user_func_array($callback, $args);
    }
    public function getCallBack(){
        return $this->callback;
    }
}



class BrainFucker{
    
    const MAX_REGISTER = 8;
    
    public $register = [];
    public $pointer = 0;
    function __construct($string){
        $this->register = array_fill(0, self::MAX_REGISTER, 0);
        $this->string = $this->cut_space($string);
        $self = $this;
        Switcher::register("+", function() use($self) {
            $self->register[$self->pointer] += 1;
        });
        Switcher::register("-", function() use($self) {
            $self->register[$self->pointer] -= 1;
        });
        Switcher::register(">", function() use($self) {
            $self->pointer += 1;
        });
        Switcher::register("<", function() use($self) {
            $self->register[$self->pointer] -= 1;
        });
        Switcher::register(".", function() use($self) {
            echo chr($self->register[$self->pointer]);
        });
    }
    
    function cut_space($string){
        return str_replace([" ", "　"], "", $string);
    }
    
    function go(){
        $exe = $this->string;
        foreach(str_split($exe) as $p){
            Switcher::onCase($p)->call();
        }
    }
}
$bf = new BrainFucker("+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++++++++++++++++++++++++++.");
$bf->go();
?>