module ArcFurnace

Backwards-compatibility

Filters limit rows to downstream nodes. They act just like Enumerable#filter: when the filter method returns true, the row is passed downstream. when it returns false, the row is skipped.

Observe all values in an input stream. All values are passed down to the next node un-adultered.

An unfold is the reverse of a fold–it takes a single value an blows it out into an enumeration of values. Useful for splitting up rows into multiple output rows and whatnot. Only unfold is required for implementation.