Functional list utilities

utils.list.js

// Requires utils.misc.js for unbind() and testers.js for existy()

var slice = unbind(Array.prototype.slice);

function toList(arr) {
	return existy(arr) ? slice(arr) : [];
}

function nth(index, list) {
	return list[index];
}

function first(list) {
	return nth(0, list);
}

function last(list) {
	return nth(list.length - 1, list);
}

function initial(list) {
	return slice(list, 0, -1);
}

function rest(list) {
	return slice(list, 1);
}