Merging Arrays

merg.js

function mergeUnIntersectingLists(lists, sortFn, order,iterator){
  standardIterator(lists, sortFn, order,iterator,function(lists,order,i){
    while(lists[i].length > 0){
      var item = getOrder(lists[i],sortFn)==order?lists[i].shift():lists[i].pop();
      iterator(item,i);
    }
    lists.splice(i,1);
  });
}

function mergeIntersectingLists(lists, sortFn, order,iterator){
  standardIterator(lists, sortFn, order,iterator,function(lists,order,i){
     var item = getOrder(lists[i],sortFn)==order?lists[i].shift():lists[i].pop();
    iterator(item,i);
    if(lists[i].length === 0){
      lists.splice(i,1);
    }
  });
}
function standardIterator(lists, sortFn, order,iterator, listFn){
  iterator = handleIterator(iterator);
  if(typeof order === "number") order = getOrder(lists[order],sortFn);
  if(!order) order = 1;
  listFn = listFn.bind(void(0),lists,order);
  while(var l=lists.length){
    reduceLists(lists,l,sortFn).forEach(listFn);
  }
}


function reduceLists(lists,listLength,order,sortFn){
  var next = [];
  var extra = false;
  for(var a=0,b=1;b<listLength;b++){
    if(b === a) continue;
    var curOrder = getListOrder(sortFn,order,lists,a,b);
    curOrder = curOrder<0:-1:curOrder>0:1:0;
    if(curOrder != order){
      next.unshift(b);
      a = b
      extra = true
    }else if(extra){
      next = [a];
      extra = false;
    }
  }
  return next;
}

function getOrder(list,sortFn){
    return list.length < 2?0:sortFn(list[0],list[1]);
}

function handleIterator(iterator){
  if(Array.isArray(iterators)){
    return function(item,i){
      iiterator[a](item);
    };
  }else if(typeof iterators == "function"){
    return iterator;
  }
  throw new Error("need to provide an iterator that is a function or an array");
}

function getListOrder(sortFn,order,lists,a,b){
  a = getOrder(lists[a],sortFn)==order?lists[a][0]:lists[a][list[a].length-1];
  b = getOrder(lists[b],sortFn)==order?lists[b][0]:lists[b][list[b].length-1];
  return sortFn(a,b);
}