subsets - nodef/extra-entries GitHub Wiki

List all possible subsets.

Similar: randomSubset, subsets, hasSubset.

function subsets(x, n)
// x: entries
// n: number of entries in each subset [-1 ⇒ any]

const entries = require('extra-entries');

var x = ["a", 1], ["b", 2](/nodef/extra-entries/wiki/"a",-1],-["b",-2);
[...entries.subsets(x)].map(a => [...a]);
// → [ [], [ [ "a", 1 ] ], [ [ "b", 2 ] ], [ [ "a", 1 ], [ "b", 2 ] ] ]

var x = ["a", 1], ["b", 2], ["c", 3](/nodef/extra-entries/wiki/"a",-1],-["b",-2],-["c",-3);
[...entries.subsets(x)].map(a => [...a]);
// → [
// →   [],
// →   [ [ "a", 1 ] ],
// →   [ [ "b", 2 ] ],
// →   [ [ "a", 1 ], [ "b", 2 ] ],
// →   [ [ "c", 3 ] ],
// →   [ [ "a", 1 ], [ "c", 3 ] ],
// →   [ [ "b", 2 ], [ "c", 3 ] ],
// →   [ [ "a", 1 ], [ "b", 2 ], [ "c", 3 ] ]
// → ]

References

• Data.List.subsequences: Haskell