just/packages/array-zip/index.js at clone · hmmhmmhm/just

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module.exports = zip;

zip([1, 2, 3]); // [[1], [2], [3]]

zip([1, 2, 3], ['a', 'b', 'c']); // [[1, 'a'], [2, 'b'], [3, 'c']]

zip([1, 2], ['a', 'b'], [true, false]); //[[1, 'a', true], [2, 'b', false]]

zip([1, 2, 3], ['a', 'b'], [true]);

// [[1, 'a', true], [2, 'b', undefined], [3, undefined, undefined]]

zip(undefined, {}, false, 1, 'foo'); // throws

zip([1, 2], ['a', 'b'], undefined, {}, false, 1, 'foo'); // throws

function zip() {

var result = [];

var args = Array.prototype.slice.call(arguments);

var argsLen = args.length;

var maxLen = 0;

var i, j;

if (!argsLen) {

throw new Error('zip requires at least one argument');

}

for (i = 0; i < argsLen; i++) {

if (!Array.isArray(args[i])) {

throw new Error('all arguments must be arrays');

}

var arrLen = args[i].length;

if (arrLen > maxLen) {

maxLen = arrLen;

}

for (i = 0; i < maxLen; i++) {

var group = [];

for (j = 0; j < argsLen; j++) {

if (!Array.isArray(args[j])) {

throw new Error('all arguments must be arrays');

}

group[j] = args[j][i];

}

result[i] = group;

}

return result;

}