Ruler replacement for context that doesn't rely on Pimple.

Context.php

<?php

namespace Ruler;

class Context implements \ArrayAccess
{
    private $values = array();

    public function __construct(array $values = array())                                                                                                     
    {   
        $this->values = $values;
    }   

    public function offsetExists($offset) {
        return isset( $this->values[$offset]);
    }   

    public function offsetGet($offset) {
        if ( is_callable( $this->values[$offset] ) ){
            return $this->values[$offset]($this);
        } else {
            return $this->values[$offset];
        }   
    }   

    public function offsetSet($offset, $value) {
        $this->values[$offset] = $value;
    }   

    public function offsetUnset($offset) {
        unset( $this->values[$offset] );
    }   
}