Named subdiagrams lose their names after being looked up

[byorgey]

{-# LANGUAGE NoMonomorphismRestriction #-}

import           Diagrams.Prelude

aCircleNamedBob :: D R2
aCircleNamedBob = circle 1 # named "bob"

whatIsTheNameOfThisCircle
  = case lookupName "bob" aCircleNamedBob of
      Nothing -> error "this doesn't happen"
      Just c  -> getSub c

itTurnsOutTheCircleAboveHasNoName
  = case lookupName "bob" whatIsTheNameOfThisCircle of
      Nothing  -> putStrLn "wah!"
      Just bob -> putStrLn "found bob"

main = itTurnsOutTheCircleAboveHasNoName

I would argue that the above program ought to print found bob, though I am open to other opinions. This bit me when building some animations via keyframing---the diagrams used to build the actual animation are looked-up subdiagrams, so one can no longer use frames of the animation as keyframes for building further animations (since there are no longer any names to match up).

[byorgey]

Note that changing this behavior will require some fun knot-tying, since diagrams contain maps from names to their subdiagrams, which means that something like circle 1 # named bob will contain itself as a subdiagram.