hasPrefix

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Subhajit Sahu edited this page Feb 3, 2021 · 11 revisions

Check if iterable starts with a prefix.

Alternatives: hasValue, hasPrefix, hasInfix, hasSuffix, hasSubsequence, hasPath.

function hasPrefix(x, y, fc, fm)
// x:  an iterable
// y:  search prefix
// fc: compare function (a, b)
// fm: map function (v, i, x)

const xiterable = require('extra-iterable');

var x = [1, 2, 3, 4];
xiterable.hasPrefix(x, [1, 2]);
// → true

xiterable.hasPrefix(x, [-1, -2]);
// → false

xiterable.hasPrefix(x, [-1, -2], (a, b) => Math.abs(a) - Math.abs(b));
// → true

xiterable.hasPrefix(x, [-1, -2], null, v => Math.abs(v));
// → true

References