function arrayToRoseTrees(array, fun) {
  return array.map(function(element) {
    return new RoseTree(element, function() { return fun(element); });
  });
}
function arrayToRoseTrees(array, fun) {
  return array.map(function(element) {
    return new RoseTree(element, function() { return fun(element); });
  });
}
function arrayToRoseTrees ( array , fun ) { return array . map ( function ( element ) { return new RoseTree ( element , function ( ) { return fun ( element ) ; } ) ; } ) ; }
Given array and fun, returns an array of rose trees where each tree's root is the element and its children are fun(element). [a] -> (a -> [a]) -> RoseTree a
Given array and fun returns an array of rose trees where each tree s root is the element and its children are fun ( element ) . [ a ] - > ( a - > [ a ] ) - > RoseTree a