Array based Set - Node.js Data Structure

Node.js examples for Data Structure:Set

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Description

Array based Set

Demo Code


/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */


importScript("../util/aUtil.js");



(function(){/*from  w ww . j  a  v  a 2 s  .c  o m*/
  var DEBUG=true;


  Array.newInstance=function(value){
    if (value === undefined || value==null) return [];
    if (value instanceof Array) return value;
    return [value];
  };//method


  Array.newRange=function(min, max, interval){
    if (interval===undefined) interval=1;
    if (min>max) Log.error();

    var output=[];
    for(var i=min;i<max;i+=interval) output.push(i);
    return output;
  };//method


  //WITH undefined AND nulls REMOVED
  Array.prototype.cleanCopy=function(){
    var output=[];
    for(var i=0;i<this.length;i++){
      if (this[i]===undefined || this[i]==null) continue;
      output.push(this[i]);
    }//for
    return output;
  };//method


  Array.prototype.copy = function(){
    //http://jsperf.com/new-array-vs-splice-vs-slice/19
    var b=[];
    var i = this.length;
    while(i--) { b[i] = this[i]; }
    return b;
  };//method


  Array.prototype.forall=function(func){
    for(var i=0;i<this.length;i++){
      func(this[i], i, this);
    }//for
  };//method

  Array.prototype.insert=function(index, value){
    this.splice(index, 0, value);
  };//method



  Array.prototype.map=function(func){
    var output=[];
    for(var i=0;i<this.length;i++){
      var v=func(this[i], i);
      if (v===undefined || v==null) continue;
      output.push(v);
    }//for
    return output;
  };//method


  Array.prototype.select=function(attrName){
    var output=[];
    if (typeof(attrName)=="string"){
      for(var i=0;i<this.length;i++)
        output.push(this[i][attrName]);
    }else if (attrName instanceof Array){
      //SELECT MANY VALUES INTO NEW OBJECT
      for(var i=0;i<this.length;i++){
        var v=this[i];
        var o={};
        for(var a=0;a<attrName.length;a++){
          var n=attrName[a];
          o[n]=v[n];
        }//for
        output.push(o);
      }//for
    }else{
      //ASSUMING NUMERICAL INDEX
      for(var i=0;i<this.length;i++)
        output.push(this[i][attrName]);
    }//endif
    return output;
  };//method


  //RETURN MAP THAT USES field AS KEY TO ELEMENTS
  Array.prototype.index = function(field) {
    var output = {};
    for (var i = 0; i < this.length; i++) {
      var v = this[i];
      if (v === undefined) continue;
      output[v[field]] = v;
    }//for
  };


  Array.prototype.groupBy=function(size){
    if (size===undefined){
      Log.error("Can only handle size parameter right now");
    }//endif

    var output=[];
    for(var i=0;i<this.length;i+=size){
      output.append({"group":i/size, "values":this.slice(i, i+size)})
    }//for
    return output;
  };//method


  //WE ASSUME func ACCEPTS (row, i, rows)
  Array.prototype.filter=function(func){

    if (typeof(func) == "function") {
      //DO NOTHING
    }else{
      func = CNV.esFilter2function(func)
    }//endif

    var output=[];
    for(var i=0;i<this.length;i++){
      if (func(this[i], i)) output.push(this[i]);
    }//for
    return output;
  };//method

  //RETURN A RANDOM SAMPLE OF VALUES
  Array.prototype.sample=function(num){
    if (this.length<num) return this;

    var temp=this.map(function(u){return {"key":Math.random(), "value":u};});
    temp.sort(function(a, b){return a.key-b.key;});
    return temp.substring(0, num).map(function(v){return v.value;});
  };

  Array.prototype.append=function(v){
    this.push(v);
    return this;
  };//method

  function appendArray(arr){
    for(var i=0;i<arr.length;i++){
      this.push(arr[i]);
    }//for
    return this;
  }//method
  Array.prototype.appendArray=appendArray;
  Array.prototype.appendList=appendArray;
  Array.prototype.extend=appendArray;


  if (DEBUG){
    var temp=[0,1,2].appendArray([3,4,5]);
    for(var i=0;i<6;i++) if (temp[i]!=i)
      Log.error();
  }//endif


  Array.prototype.prepend=function(v){
    this.unshift(v);
    return this;
  };//method

  Array.prototype.last=function(){
    return this[this.length-1];
  };//method

  Array.prototype.first=function(){
    if (this.length==0) return null;
    return this[0];
  };//method

//  Array.prototype.indexOf=function(value){
//    for(var i=0;i<this.length;i++){
//      if (this[i]==value) return i;
//    }//for
//    return -1;
//  };//method

  Array.prototype.substring=Array.prototype.slice;

  Array.prototype.left=function(num){
    return this.slice(0, num);
  };

  //TRUNCATE ARRAY IF LONGER THAN num
  Array.prototype.limit=Array.prototype.left;

  Array.prototype.leftBut = function(amount){
    return this.slice(0, this.length - amount);
  };//method

  Array.prototype.right=function(num){
    return this.slice(Math.max(0, this.length-num));
  };

  Array.prototype.rightBut=function(num){
    if (num<=0) return this;
    return this.slice(num , this.length);
  };



  Array.prototype.remove=function(obj, start){
    while(true){
      var i=this.indexOf(obj, start);
      if (i==-1) return this;
      this.splice(i, 1);
    }//while
  };


  Array.prototype.concatenate=function(separator){
    return this.map(function(v){return v;}).join(separator);
  };

  //RETURN TRUE IF VALUE IS FOUND IN ARRAY
  Array.prototype.contains = function(value){
    return this.indexOf(value)>=0;
  };//method


  //RETURN LIST OF COMMON VALUES
  Array.prototype.intersect = function(b){
    var output = [];
    for(var i = 0; i < this.length; i++){
      for(var j = 0; j < b.length; j++){
        if (this[i] == b[j]){
          output.push(this[i]);
          break;
        }//endif
      }//for
    }//for
    return output;
  };//method


  //RETURN UNION OF UNIQUE VALUES
  //ASSUMES THAT THE COORCED STRING VALUE IS UNIQUE
  //EXPECTING EACH ARGUMENT TO BE AN ARRAY THAT REPRESENTS A SET
  Array.prototype.union = function(){
    return Array.union.apply(undefined, [].appendArray(arguments).append(this));
  };//method

  //RETURN UNION OF UNIQUE VALUES
  //ASSUMES THAT THE COORCED STRING VALUE IS UNIQUE
  //EXPECTING ONE ARGUMENT, WHICH IS A LIST OF AN ARRAYS, EACH REPRESENTING A SET
  Array.union = function union(){
    var arrays = (arguments.length==1  && arguments[0] instanceof Array) ? arguments[0] : arguments;

    var output={};
    for (var j = arrays.length; j--;) {
      var a = Array.newInstance(arrays[j]);
      for (var i = a.length; i--;) {
        var v = a[i];
        output[v] = v;
      }//for
    }//for
    return Map.getValues(output);
  };


  function AND(values){
    for(var i=values.length;i--;){
      var v=values[i];
      if (v==false) return false;
    }//for
    return true;
  }
  Array.AND=AND;


  Array.extend=function extend(){
    var arrays = (arguments.length==1  && arguments[0] instanceof Array) ? arguments[0] : arguments;
    var output=[];
    for(var i=0;i<arrays.length;i++){
      var a = Array.newInstance(arrays[i]);
      output.appendArray(a);
    }//for
    return output;
  };


  Array.prototype.subtract=function(b){
    var c=[];
  A:  for(var x=0;x<this.length;x++){
    var v=this[x];
      if (v!==undefined){
        for(var y=b.length;y--;) if (v==b[y]) continue A;
        c.push(v);
      }//endif
    }//for
    return c;
  };//method
})();

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