errant/tacit

<?php 
namespace Tacit\Instruction\Type;
/**
 * Integer Type
 *
 * @author Tom Morton
 */
class Int extends \Tacit\Instruction {

    public $command = 'INT';

    public function execute($vm)
    {
        $vm->pointer++;
        $vm->stack->push($vm->getByte());
    }

    public function compile(&$bytestream, $byte, $command)
    {
        if(!isset($command['T_OPERAND'])) {
            throw new \Exception('Type INT expects an operand');
        }

        if(!is_numeric($command['T_OPERAND'])) {
            throw new \Exception('Type INT expects an integer as operand');
        }

        if((int) $command['T_OPERAND'] > 255) {
            throw new \Exception('Type INT overflow (0-255)');
        }

        $bytestream[] = $byte;

        $bytestream[] = (int) $command['T_OPERAND'];

    }
}