function minEntry(x, fc, fm)
// x:  entries
// fc: compare function (a, b)
// fm: map function (v, k, x)

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

var x = [["a", 1], ["b", 2], ["c", -3], ["d", -4]];
entries.minEntry(x);
// → [ "d", -4 ]

entries.minEntry(x, (a, b) => Math.abs(a) - Math.abs(b));
// → [ "a", 1 ]

entries.minEntry(x, null, v => Math.abs(v));
// → [ "a", 1 ]