If I'm following, you've created a division of labor between setReader and reset.
We have a tokenizer that has a good deal of state, since it has to split the input into chunks. If I'm following here, you'd recommend that we do nothing special in setReader, but have #reset fix up all the state on the assumption that we are are starting from the beginning of something, and we'd reinitialize our chunker over what was sitting in the protected 'input'. If someone called #setReader and neglected to call #reset, awful things would happen, but you've warned them. To me, it seemed natural to overload #setReader so that our tokenizer was in a consistent state once it was called. It occurs to me to wonder about order: if #reset is called before #setReader, I'm up creek unless I copy my reset implementation into a local override of #setReader.
