Pass data from one filter to another?

[joefiorini]

Let's say I want to add a filter that allows template rendering options (mainly the layout) to be specified in YAML front matter. It seems to me that filters should be small and composable; therefore I don't want to force my Tilt filter to also handle front matter. How would I write a filter in such a way that it can parse out the front matter then hand that off to the next filter?