Collect tokens from stream as well as rule return values

[cwaldbieser]

I'm parsing a script into tokens, and I'd like to store the parsed results of the child rules and the slice of consumed input (like the angle-brackets shortcut). In the grammar that receives these tokens, the context will determine whether the parsed results can be used, or if the original input is needed. I'm not sure if there's a way store both of these things at once with Parsley.