difference

difference

Values in the first stream not present in any of the remaining streams, deduplicated. {1,2,3} ∖ {2} = {1,3}.

import difference from 'stream-sorting/sorted/difference.js';

for await (const v of difference([primary, exclude1, exclude2])) {
  // values from `primary` that appear in neither exclude stream
}

streams is an array of sorted AsyncIterable<T> | Iterable<T>; streams[0] is the source and streams[1..] are subtracted from it. The result is an AsyncIterable<T>, each surviving value emitted once. With only one stream it deduplicates that stream.

Options

Option	Type	Default	Description
compare	(a, b) => number	natural order	Orders items and defines equality. compare OR lessFn.
lessFn	(a, b) => boolean	—	Strict-less comparator. compare OR lessFn.

Two items are "equal" when the comparator ranks neither below the other. An out-of-order input throws when the offending item is reached.

See also

union, intersection, merge, and the key-based filters matching / unmatched.