Maybe this is known and just awaiting prose, but the sense left in the last few messages isn’t clear.
You are pre-computing the doubled object which in turn has a doubled-object to pre-compute, etc. The interface should have a function from unit to the doubled object and the top-level Thing wrapper can have a function which hides. (If Elm 0.19 had not removed lazy values, you could put a lazy object into the interface and force it in the top-level wrapper to avoid recomputes.)
