Returns a value as comparer.
A comparer has the following structure:
function (x, y) : number;
Examples
// x == y
var comparer1 = Enumerable.toComparerSafe();
// from Lambda
var comparer2 = Enumerable.toComparerSafe('(x, y) => y - x');
// from function
var comparer3 = Enumerable.toComparerSafe(function(x, y) {
return y - x;
});
// THROWS EXCEPTION
Enumerable.toComparerSafe('test');