I think this is not going to work. We somehow need to figure out what separator is used for this field in the shingle filter. We can't just use the default seperator since it needs to be the same as the shingle filter. This is also what confuses me with regards to summing up the ttf for all terms above in line 386. We have to somehow detect if it is a shingle or not :)

I guess we still have to somehow use a mapper for this and maybe generalize the mapper we use for completion fields to figure out the right settings. We might be able to allow mappers to pass information to the actual postings format but who knows.