extension builder

[cymqqqq]

I noticed that now there are GenesisIface, TransitionIface, and ExtensionIface, related to ContractBuilder, and TransitionBuilder. But there is no ExtensionBuilder, so do we also need an ExtensionBuilder?

I also noticed that for the ExtensionIface, there is a redeem structure(It's not a state, but a valency type), maybe related to the input in the TransitionIface, so if there is an ExtensionBuilder with a redeem parameter, then what does the redeem actually work for?

[dr-orlovsky]

Yes, extension builder will be needed.

Extension doesn't close any single-use seals though; its inputs are redeems. Redeems do redeem valencies, defined by other operations; it is the way how one link them into the contract history graph.