Setoid example

The example of setoid uses equality between the elements of the array but it assumes there's an equality operator (==) between the elements of the setoid.

I would do the following:

Number.prototype.equals = function(num) {
  return num.valueOf() === this.valueOf();
}

(2).equals(2) // true
(2).equals(3) // false

Array.prototype.equals = function(arr) {
    var len = this.length
    if (len !== arr.length) {
        return false
    }
    for (var i = 0; i < len; i++) {
        if (! this[i].equals(arr[i])) {
            return false
        }
    }
    return true
}


[1,2].equals([1,2]) // true
[1,2].equals([1,2,3]) // false
[1,2].equals([2,3]) // false

Start by locating the setoid example in the repository and read its explanation alongside the issue's proposed equality behavior. Update the example so its equality assumption is explicit and verify that the displayed examples produce the stated results.