Different command history for each prompt?

[fsktom]

Currently there's only one command history for the UI

>>> plot compare rel
1st trace: artist, album or song?
   > artist
Artist name?
  >> NF
2nd trace: artist, album or song?
   > artist
Artist name?
  >> Hoshimachi Suisei

^ for something like this going Up goes through each input
but would be nice if you're at >>> if it only went through other >>> inputs and the same for >> and >
I wonder how difficult this would be to implement (or if it's even possible)...