如何在Twig扩展中的Token Parser中获取变量

Question

I'm having trouble getting the correct data passed in my twig extension

Example token parser parse function:

public function parse(\Twig_Token $token)
{
    $parser = $this->parser;
    $stream = $parser->getStream();

    $firstVariable = $stream->getCurrent();    
}

The expression {% myTag "someString" %}will set $firstVariable as 'someString'.

However if we put in place a variable:

{% set someVariable = "someString" %}
{% myTag someVariable %}

You end up with a name type with the value 'someVariable' instead of the expected variable value 'someString'

How do I properly parse the first argument of my custom twig tag, allowing the input to either be a string or a variable containing a string?

Edit

It looks like you can just take the variable name and use it in the returned twig node.

public function compile(){
    $compiler->write('echo "$context[$variableName]"');
}

But I need access to it before compiling.

Edit I no longer believe it's possible to access the context before compiling. Making this question a dud unless anyone has some more information to share on the subject