<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>
        <service id="markdown.parser.sundown" class="Knp\Bundle\MarkdownBundle\Parser\SundownParser" public="false">
            <argument type="service" id="markdown.sundown.base_parser" />
        </service>

        <service id="markdown.sundown.base_parser" public="false" class="Sundown\Markdown">
            <argument type="service" id="markdown.sundown.renderer" />
            <argument>%markdown.sundown.extensions%</argument>
        </service>

        <service id="markdown.sundown.renderer" public="false" class="Sundown\Render\HTML">
            <argument>%markdown.sundown.render_flags%</argument>
        </service>
    </services>
</container>

<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="markdown.parser.sundown.class">Knp\Bundle\MarkdownBundle\Parser\SundownParser</parameter>
        <parameter key="markdown.sundown.base_parser.class">Sundown\Markdown</parameter>
        <parameter key="markdown.sundown.renderer.class">Sundown\Render\HTML</parameter>
    </parameters>

    <services>
        <service id="markdown.parser.sundown" class="%markdown.parser.sundown.class%" public="false">
            <argument type="service" id="markdown.sundown.base_parser" />
        </service>

        <service id="markdown.sundown.base_parser" public="false" class="%markdown.sundown.base_parser.class%">
            <argument type="service" id="markdown.sundown.renderer" />
            <argument>%markdown.sundown.extensions%</argument>
        </service>

        <service id="markdown.sundown.renderer" public="false" class="%markdown.sundown.renderer.class%">
            <argument>%markdown.sundown.render_flags%</argument>
        </service>
    </services>
</container>

Make the Sundown service classes overridable using parameters
Make the Sundown service classes overridable using parameters
