bisect: build a displayer only once There is multiple spot using this, building it early will help to extract more of the logic into the bisect module.

bisect: factor commonly update sequence For now, This remains a closure in the module to avoid circular import with used module.

bisect: move check_state into the bisect module Now that the function is simpler, we resume our quest to move the logic into the bisect module. In the process, we add basic documentation.

bisect: simplify conditional in 'check_state' Now that extra code about "updating" flag have been removed, we can simplify the condition flow and remove a level.