ArrayList类（增强版）

Author:月影
From:http://bbs.51js.com/thread-66469-1-1.html

<script>  
function ArrayList()  
{  
  var ins = Array.apply(this, arguments);  
  ins.constructor = arguments.callee;  
  ins.base = Array;  

  ins.each = function(closure)  
  {  
    if(typeof closure == 'undefined')  
      closure = function(x){return x};  
    if(typeof closure != 'function')  
    {  
      var c = closure;  
      closure = function(x){return x == c}  
    }  

    var ret = new ArrayList();  
    var args = Array.apply(this, arguments).slice(1);  

    for(var i = 0; i < this.length; i++)  
    {  
      var rval = closure.apply(this, [this[i]].concat(args).concat(i))  
      if(rval || rval === 0)  
        ret.push(rval);  
    }  

    return ret;  
  }  

  ins.trim = function()  
  {  
    return this.each.apply(this);  
  }  

  ins.all = function(closure)  
  {  
    return this.each.apply(this, arguments).length == this.length;  
  }  

  ins.any = function(closure)  
  {  
    return this.each.apply(this, arguments).length > 0;  
  }  

  ins.contains = function(el)  
  {  
    return this.any(function(x){return x == el});  
  }  

  ins.indexOf = function(el)  
  {  
    var ret = this.each.call(this, function(x, i){return el == x?i:false})[0];  
    return ret ? ret : -1;  
  }  

  ins.subarr = function(start, end)  
  {  
    end = end || Math.Infinity;  
    return this.each.call(this, function(x, i){return i >= start && i < end ? x : null});  
  }  

  ins.valueOf = ins.toString;  

  ins.toString = function()  
  {  
    return '['+this.valueOf()+']';  
  }  

  ins.map = function(list, closure)  
  {  
    if (typeof list == 'function' && typeof closure != 'function')  
    {  
      var li = closure;  
      closure = list;  
      list = li;  
    }  
    closure = closure || ArrayList;  

    return this.each.call(this, function(x, i){return closure.call(this, x, list[i])});  
  };  

  ins.slice = function()  
  {  
    return this.constructor(ins.base.prototype.slice.apply(this, arguments));  
  }  

  ins.splice = function()  
  {  
    return this.constructor(ins.base.prototype.splice.apply(this, arguments));  
  }  

  ins.concat = function()  
  {  
    return this.constructor(ins.base.prototype.concat.apply(this, arguments));  
  }  

  return ins;  
}  

var a = new ArrayList(1,2,3);  
alert(a.length);  
alert(a);  
alert(a instanceof Array);  
alert(a.constructor);  
alert(a instanceof ArrayList); // 可惜这个值不对，但是没法实现，只好放弃了  

alert(a.each(function(x){return x+x}));  
alert(a.all(function(x){return x>0}));  
alert(a.all(function(x){return x<1}));  
alert(a.any(function(x){return x == 2}));  

alert(a.contains(2));  
alert(a.contains(-1));  

var b = a.map([3,2], function(x, y){return x+y});  
alert(b);  
alert(a.map([2,3,4]));  

alert(a.indexOf(2));  
alert(a.indexOf(-1));  

alert(a.subarr(1,3));  
alert(a.toString());  
var b = new ArrayList(a,a);  
alert(b.toString());  
alert(b.slice(1));  
</script>

arr.all 是当数组（集合）中的所有元素都满足条件时，返回true，否则返回false
arr.any 是当数组（集合）中的所有元素中任意一个满足条件时，返回true，如果都不满足，返回false
arr.each 返回由符合条件的每一个元素构成的子数组
arr.map 是匹配两个数组（集合）并把它们的元素用指定闭包进行计算