js:数据结构笔记2---列表

function List() {
   this.listSize = 0;
   this.pos = 0;
   this.dataStore = [];
   this.find = find;
   .........................
}

function append(element) { this.dataStore[this.listSize++] = element; }

 function find(element) {
      for(var i=0; i < this.dataStore.length; ++i) {
       if(this.dataStore[i] === element) {
            return 1;  
      }
   }
    return -1;
}

 function  remove() {
   var foundAt = this.find(element);
   if(foundAt > -1) {
     this.dataStore.splice(foundAt,1);
     --this.listSize;
     return true;
   }
   return false;
}

function length() {
   return this.listSize;
}

function toString() {
   return this.dataStore;
}

function insert(elem,after) {
   var insertPos = this.find(elem);
   if(insertPos > -1) {
     this.dataStore.splice(insertPos+1,0,elem);  //
     ++this.listSize;
     return true;
  }
  return false;
}

function clear() {
   delete this.dataStore;
   this.dataStore = [];
   this.listSize = this.pos = 0;
}

function contains(elem) {
   for(var i = 0; i < this.dataStore.length; ++i) {
      if(this.dataStore[i] ===  elem) {
          return true;
     }
  }
     return false;
}

function front() {
  this.pos = 0;    //pos范围[0-listSize-1]
}

function end() {
  this.pos = this.listSize - 1;
}

function prev() {
  if(this.pos > 0) {
    --this.pos;
  }
}

function next() {
  if(this.pos < this.listSize-1) {
    ++this.pos;
  }
}

function currPos() {
  return this.pos;
}

function moveTo(position) {
  this.pos = position;
}

function getElement() {
  return this.dataStore[this.pos];
}