> arbitrary semantics I wouldn't go so far to say it is arbitrary (unless someone uses it wrongly :) ). As far as I know, a bang name only exists if a non-ban

> arbitrary semantics I wouldn't go so far to say it is arbitrary (unless someone uses it wrongly :) ). As far as I know, a bang name only exists if a non-bang name exists as well. And the one with ! indicates an unexpected or comparatively dangerous outcome, such as a mutation, raising an exception, bypassing some normal check, etc.