pairs.js

pairs.js

// Requires underscore for zip function.

function slice(array, from, to, step) {
    if (from===null) from=0;
    if (to===null) to=array.length;
    if (!step) return array.slice(from, to);
    var result = Array.prototype.slice.call(array, from, to);
    if (step < 0) result.reverse();
    step = Math.abs(step);
    if (step > 1) {
        var final = [];
        for (var i = result.length - 1; i >= 0; i--) {
            (i % step === 0) && final.push(result[i]);
        };
        final.reverse();
        result = final;
   }
   return result;
}

var numbers = [1,2,3,4,5,6];


function pairs(a) {
    return = _.zip(slice(numbers, 0, numbers.length, 2),
                   slice(numbers, 1, numbers.length, 2));
}