Difference between Dataset and Loader

[clegaard]

What is the difference between a Dataset and a Loader? From a conceptual standpoint, a loader behaves exactly like a dataset. In terms of the implementation, it seems like the Loader simply wraps the dataset?

[LukasHedegaard]

Now that Loader.extend was removed, you are right. It just wraps a function in a concrete ItemGetter class. We could remove it, but then all the other from_* functions would need to define the concrete ItemGetter. The alternative could be to extend the Dataset.__init__ to allow the parent to be a function. We could do this by moving the logic from Loader.__init__ into Dataset.__init__. The downside to this would be that we add more logic to an already complex function.