gistfile1.txt

<?php

class CalcSteps
{
    protected $calc;
    protected $screen;

    public function start()
    {
        $this->calc = new Calc();
    }

    public function getSteps()
    {
        return array(
            '/I start the calculator' => array($this, 'start'),
            '/I have entered (.*) in the calculator' => array($this, 'enterValue'),
            '/I press add' => array($this, 'pressAdd'),
            '/The result should be (.*) on the screen/' => array('resultShouldBe')
        );
    }

    public function pressAdd()
    {
        $this->screen = $this->calc->getSum();
    }

    public function enterValue($value)
    {
        $this->calc->add($value);
    }

    public function resultShouldBe($value)
    {
        assertEquals($value, $this->screen);
    }
}

It will not work. At all!