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const map = require('extra-map'); var x = new Map([['a', 1], ['b', 2], ['c', 3], ['d', 2]]); map.scanUntil(x, v => v % 2 === 0); map.scanUntil(x, v => v % 8 === 0);

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@extra-map/scan-until v2.2.7

Finds key of first entry passing a test.

Finds key of first entry passing a test. :running: :package: :ledger:

Alternatives: scanWhile, scanUntil.
This is part of package extra-map.

map.scanUntil(x, ft);
// x:  a map
// ft: test function (v, k, x)
const map = require('extra-map');

var x = new Map([['a', 1], ['b', 2], ['c', 3], ['d', 2]]);
map.scanUntil(x, v => v % 2 === 0);
// 'b'                       ^

map.scanUntil(x, v => v % 8 === 0);
// undefined

references

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