anonymous [memoized] fibonacci range, using y-combinator in JavaScript

Y-Fibinator.js

(function(Y, memoize){
  return (function(range, map, fib) {
    return function(a, b) {
      return map(fib, range(a, b));
    };
  })(
    Y(function(range, a, b, inc) {
      inc = inc || 1;
      if(a === b) return [a];
      return [a].concat(range(range, a+1, b));
    }),
    Y(function(map, fn, arr) {
      if(!arr.length) return [];
      return [fn(arr[0])].concat(map(map, fn, arr.slice(1)));
    }),
    Y(memoize(function(fib, num) {
      if(num < 2) return 1;
      return fib(fib, num-2)+fib(fib, num-1);
    }))
  );
})(
  function(fn) {
    return function() {
      var args = [].slice.call(arguments);
      return fn.apply(null, [fn].concat(args));
    };
  },
  function(fn) {
    var memo = {};
    return function() {
      var args = [].slice.call(arguments),
          key = args.join(',');
      return memo[key] || (memo[key] = fn.apply(null, args));
    };
  }
)(0, 100);