Prototype Hash对象 学习

//Hash对象的工具函数 
function $H(object) { 
return new Hash(object); 
}; 

var Hash = Class.create(Enumerable, (function() { 

//初始化，创建一个新的Hash对象 
function initialize(object) { 
this._object = Object.isHash(object) ? object.toObject() : Object.clone(object); 
} 

//覆盖Enumerable里面的方法，遍历Hash对象时会用到 
function _each(iterator) { 
for (var key in this._object) { 
var value = this._object[key], pair = [key, value]; 
pair.key = key; 
pair.value = value; 
iterator(pair); 
} 
} 

function set(key, value) { 
return this._object[key] = value; 
} 

function get(key) { 
if (this._object[key] !== Object.prototype[key]) 
return this._object[key]; 
} 

function unset(key) { 
var value = this._object[key]; 
delete this._object[key]; 
return value; 
} 

function toObject() { 
return Object.clone(this._object); 
} 

function keys() { 
return this.pluck('key'); 
} 

function values() { 
return this.pluck('value'); 
} 

//返回value的key 
function index(value) { 
var match = this.detect(function(pair) { 
return pair.value === value; 
}); 
return match && match.key; 
} 

function merge(object) { 
return this.clone().update(object); 
} 

//更新原有Hash对象，把object参数内的键值对更新到原Hash对象 
function update(object) { 
return new Hash(object).inject(this, function(result, pair) { 
result.set(pair.key, pair.value); 
return result; 
}); 
} 

function toQueryPair(key, value) { 
if (Object.isUndefined(value)) return key; 
return key   '='   encodeURIComponent(String.interpret(value)); 
} 

function toQueryString() { 
return this.inject([], function(results, pair) { 
var key = encodeURIComponent(pair.key), values = pair.value; 

if (values && typeof values == 'object') { 
if (Object.isArray(values)) 
return results.concat(values.map(toQueryPair.curry(key))); 
} else results.push(toQueryPair(key, values)); 
return results; 
}).join('&'); 
} 

function inspect() { 
return '#'; 
} 

function toJSON() { 
return Object.toJSON(this.toObject()); 
} 

function clone() { 
return new Hash(this); 
} 

return { 
initialize: initialize, 
_each: _each, 
set: set, 
get: get, 
unset: unset, 
toObject: toObject, 
toTemplateReplacements: toObject, 
keys: keys, 
values: values, 
index: index, 
merge: merge, 
update: update, 
toQueryString: toQueryString, 
inspect: inspect, 
toJSON: toJSON, 
clone: clone 
}; 
})()); 

Hash.from = $H;

clone
each
get
inspect
keys
merge
remove
set
toJSON
toObject
toQueryString
unset
update
value
给出一些方法的示例，简单的方法就略过了
toQueryString()：

$H({ action: 'ship', order_id: 123, fees: ['f1', 'f2'], 'label': 'a demo' }).toQueryString() 
// -> 'action=ship&order_id=123&fees=f1&fees=f2&label=a demo' 

// an empty hash is an empty query string: 
$H().toQueryString() 
// -> ''

update()：

var h = $H({ name: 'Prototype', version: 1.5 }); 
h.update({ version: 1.6, author: 'Sam' }).inspect(); 
// -> # 

h.inspect(); 
// -> # 

//注意这里会改变原来的Hash对象

merge():

var h = $H({ name: 'Prototype', version: 1.5 }); 
h.merge({ version: 1.6, author: 'Sam' }).inspect(); 
// -> # 

h.inspect(); 
// -> # 

//注意这里不改变原有Hash对象