Decoder could do with a PeekUint8, or a way to see the unconsumed slice #11
Description
I am working on a decoder where I want to look at a code to discriminate the next type of object (high level Go object, not the low level primitive types that this library supports.)
Btw, this could also be true if I wanted to (for example) discriminate between different types based on a map key (as an example).
The simplest thing might be simply allow a consumer to get the remaining (unconsumed) byte slice. Then scratch slices could be used for any lookahead processing, while allowing the caller to go "back" to an earlier point in time in the parse.
(Another option would be to provide a Clone() method to make a deep copy of the Decoder structure.)