精品国产一二,性视频一区二区三区,亚洲影院一区

amenglai — Wed, 20 Jan 2010 03:45:00 GMT

前天�q�本PEAA�l�于�l�我��d��了。其实这本书�q�是我在2004�q�买的，记得当时�q�买了那本著名的refector�Q�那本书当时��p��完了�Q�而这本PEAA�Ҏ(gu��)��看不下去�?br /> 现在�l�于��d��了，看来�q�几�q�的�z�M��是白�q�的哦，如果没有收获�Q�咋能��生共鸣呢。可是我却写不出��M��W�记�Q�好像有很多的体�?x��)，但是一旦坐在电(sh��)脑前�Q�又大脑一片空白�?img alt="" src="/CuteSoft_Client/CuteEditor/images/emembarrassed.gif" align="absMiddle" border="0" />�Q�那是因��Z��q�没有理�?img alt="" src="/CuteSoft_Client/CuteEditor/images/emcry.gif" align="absMiddle" border="0" />�Q�鉴定完毕）
But�Q�读完和理解之间�q�有chasm需要跨��，是的�Q�我�?x��)在H�pȝ��的重构上��L��M��用它�?img alt="" src="/CuteSoft_Client/CuteEditor/images/face1.gif" align="absMiddle" border="0" />�q�样才会(x��)有体�?x��)�?br /> 其实�q�本书应该先去读base pattern部分�Q?/span>因�ؓ(f��)Martin大叔的很多pattern都会(x��)用到base pattern�Q�但是偶不知他老�h家�ؓ(f��)啥把�q�部分放在了最后�?br /> 今天�Q�从今天开始，我开始新的C++journey�Q�Effecitive C++�?

amenglai 2010-01-20 11:45 发表评论

《分析模式》读后感

amenglai — Wed, 22 Apr 2009 05:29:00 GMT

�l�于把《分析模式》读完了�Q�没惛_��׃��q?个月的时间。读的这么辛�?img src="/CuteSoft_Client/CuteEditor/images/emsad.gif" align="absMiddle" border="0" alt="" />
不可否认�Q�这是一本可�?#8220;怡情”的好书。前面的9章是最值得一�ȝ��?br /> 但是我想大叔在写�q�本书时�Q�还没有能够�?#8220;refactor”旉��样高度概括，所以书中掺杂了很多财务的专业知识背景，我，没有做过�Q�所以读��h��很费劌Ӏ?/p>

是的
从明天�v�Q�我��做个C++�?br /> 和Lippman周游世界

amenglai 2009-04-22 13:29 发表评论

amenglai — Thu, 16 Apr 2009 09:34:00 GMT

久�ԒSmallTalk的大名，大概是因为很�?/span>design pattern的名著都提到它，�q�且一说到OOAD也都�?x��)提到它老�h家。但是我�q�不知道它是啥子东东�Q�就像谁兛_��Ada一栗��?/span>

但是出来��h��L��需要还�?/span>L没想�?/span>Martin大叔�?#8220;分析模式”竟然是用�q�个��g��西写的代码，额的��啊�Q�我只好打�v万分的精��，恶补一下�?/span>

最不幸的是�|�上能够扑ֈ�的关�?/span>SmallTalk书，��实�?/span>Java��得多的多。找��C��?/span>E文的�Q�将��吧�?/span>

另外的发现就�?/span>ruby��L(f��ng)��ruby>(smalltalk+perl)�Q�所以有些资料可以在ruby中找到哈�?/span>

我的�q�䆾Smalltalk的学�?f��n)笔讎ͼ��q�不是按�?/span>Smalltalk�q�阶的思�\整理的，而是在阅�?/span>AP�W�七章的�q�程中随用到随整理的。看AP是够用了�?/span>

变量和赋�?/span>

字符 $a $1

字符串变量，用单引号表示。注意在SmallTalk中双引号是注释。所�?/span>

‘John’ ‘Martin’�q�是对的�?/span>

A := “John Hunt”�q�是错的�Q�去�?/span>? �Q?/span>

‘a’�?/span>$a表示的是不同�cȝ��实例�Q�前者对应的Strings�Q�后者对应的Charater�?/span>

Symbols

我觉得这��q��当于java中的帔R��

#join week system42

赋�?/span> := �Q�这个和Delphi一样哈�Q?/span>

myName := ‘John Hunt

newIndex := oldIndex

临时变量

|x y z|

x :=5.

y :=6.

Z :=x+y.

Transcript show: z printString.

isKindof�Q�类型判�?/span>

(anObject isKindOf: String) ifTrue: [...] ifFalse: [...] is an example of Smalltalk's runtime equilivant of "type testing"

集合

Enumerating Collections

do – does the same operation on every element of the collection.

MyCollection do: [:piece | piece reset]

�?/span>MyCollection的每�?/span>element发送消�?/span>reset�Q�其实就是执�?/span>reset�Q?/span>

collect – like do: but returns a collection of the results.

select – test every element and returns those which pass.

reject – test every element and returns those which fail.

detect – returns the first element which passes the test

inject:into

inject

�?/span>Smalltalk语言中也支持集合的�P代器�Q�如果你要求Smalltalk�E�序员求数组元素的和�Q�他们会(x��)像这��h��使用inject函数�Q?/span>

sumOfValues "Smalltalk method"

^self values

inject: 0

into: [ :sum :element | sum + element value]

inject是这样工作的�Q�当兌��的代码块�W�一�ơ被调用�Ӟ��sum被赋�l?/span>inject的参数��|��在这里是0�Q�，element取数�l�第一个元素。第二次和以后调用到代码块时�Q?/span>sum被赋�l�上�ơ调用代码块时返回的��|��q�样sum��p��完了全程�Q?/span>inject最�l�的�l�果是代码块最后被调用的倹{�?/span>

Dictionary

Dictionary�?/span>Set的子�c�R�?/span>

at : aKey 对应Java�?/span>get(key)

at : aKey put : aValue对应Java�?/span>put(key, value)

应用方式�Q?/span>

Code Block

[ :params | ]

Where :params is the list of parameters the code can take. This means that the Smalltalk code:

[:x | x + 1]可以理解为：(x��)f(x) = x + 1

Code Block的调用：(x��)

[:x | x + 1] value: 3

can be evaluated as

f(3) = 3 + 1

�q�是相等�?/span>Code Block的定义和调用在一赗��?/span>

令一�U�方法是先定�?/span>code Block,然后在其它的地方再调用�?/span>

anotherBlock := [ :parml :parm2 | | temp |

temp := pannl incorporate: parm2.

temp rehash.

说明�Q?/span>

1) 定义Code Block�Q?/span>anotherBlock�?/span>

2) parml �Q?/span>parm2是两个参�?/span>

3) temp是定义的变量

调用�Q?/span>anotherBlock value: objecfcl value: object2

��管狠不适应�Q�但�?/span>Code Block可以使得代码��z�明了：(x��)

positiveAmounts := allAmounts select: [:amt | amt isPositive]

�q�句话就是从collection allAmounts�q�回所�?/span>positive的单元的集合�?/span>amt按我的理解就是对应的每个element�?/span>

amenglai 2009-04-16 17:34 发表评论

Chapter6 Inventory and Accounting

amenglai — Thu, 16 Apr 2009 07:02:00 GMT

My comments

�Q?/span>2009-2-3�Q?/span>

在读�q�章�Ӟ��对于�q�章开始的2��|��q�C��定要反复的读。尤其是当读到后�l�小节，感觉�q�失方向的时候，一定要回来再读�q�部分，�q�部分是�q�章的一个高度的概括�?/span>

如果不具备会(x��)计的知识背景�Q�花半天的时间恶补一下。徏议看看《会(x��)计学原理�Q�新�~�）》（徐文彬）。了解几个关键的术语�Q��̎�?/span>,�?x��)计�U�目,复式记�̎�?/span>

我先云山雄��的读了一遍，再回头看�q�章的开始部分，对于Martin的阐�q�思�\了解的清��C��Q�另外在恶补�q�基本的�?x��)计知识后，�?/span>Transaction�?/span>Summary Account理解��h��老轻松了�Q�真是磨刀不误砍柴�?/span>J

Brief Summary

Account�Q��̎�?/span>

Entry�Q�记账分�?/span>

Account can only be added or removed by entries. The entries provide a history of all changes of the account.

Account and Entry

Transactions

Transactions add a further degree of auditability by linking entries together. In a transaction, the items withdrawn from one account must be deposited in another. (我理解这句话的意思其实就是会(x��)计中所�q�的复式记�̎Double entry�Q�复式记账一般就是指借贷记�̎)

一般的Transsction��是财务上所说的“一借一�?#8221;�Q��?/span>Multiegged Transsction��是财务上所说的“一借多�?#8221;或�?#8220;一贷多�?#8221;�?/span>

导入以下的会(x��)计知识：(x��)

�q�是资��c�d��L(f��ng)��余额。如果是负债或所有者权益类帐户�Q�七期初余额、期末余额一般应在贷斏V�?/span>

费用�c�d��户和资��c�d��户一��P��收入和利润帐户和负债或所有者权益类帐户�?/span>

“�?#8221;表示资��增加或负��Z��?qi��ng)所有者权益的减少�Q?#8220;�?#8221;表示资��减少或负��Z��?qi��ng)所有者权益的增加.

“有借必有贷�Q�借贷必相�{?/span>”

Summary account�Q�汇总�̎�?/span>

帐户是根据会(x��)计科目开讄��。会(x��)计科目既有��d��cȝ��目和明细�U�目�Q�帐户也��有��d��c�d��户和明细帐户�?/span>

‘原材�?#8217;是一个��d��c�d��P��它只能概括但应所有原材料的增减变化以其结果。在‘原材�?#8217;帐户下面�Q�还要按照每一�U�原材料分别讄��明细分类帐户�?/span>

‘应收账款’是一个��L��反映应收账款�l�算情况的��d��c�d��P��Z��详细反映应收账款的结��情况，�q�必��L��每一个客戯��|�应收�̎�ƾ明�l�分�c�d��戗��?/span>

Memo account�Q�备注�̎�?/span>

备注账户�q�不需要保持��^衡�?/span>

No real money leaks from or to a memo account.

Posting rules�Q�簿记规则）

对于Posting rules�Q?/span>Martin要从以下的几个方面来阐述�Q?/span>

1. Posting rules是什�?/span>

Posting rules allow us to build active networks of accounts that update each other and reflect business rules.

2. 如何实现��记规则�Q?/span>Individual instance method

��Z��么要引入Individual instance method�Q�这是因为簿记规则往往很复杂，不会(x��)仅仅是乘以一个系数这么简单。例如计�E�，不同的金额对应不同的�E�率。也��是说对于不同的实例�Q?/span>instance�Q�会(x��)对应不同�?/span>behavior�?/span>

3. Posting rules如何被执�?/span>

Posting rule execution pattern describes ways in which posting rules can be triggered.

4. Posting rules在哪里定�?/span>

Posting rules for many accounts

Choosing entries

Accounting practice pattern: �q�是��Z��l?/span>Posting rules�q�行分类

The source of an entry

Balance sheets and income statements(资��负��和损益表)

Corresponding account

Specialized account model

Transactions

Account, entry�?/span>Transactions�q�三者之间的关系通过UML体现。这是这章的基础�?/span>

entry�?/span>Transactions之间的关�p�d��如同是先有鸡�q�是先有蛋的问题。因为有�U�束条�g�Q�如果没有创�?/span>Transactions��׃��能创�?/span>entry�Q�同��h��?/span>entry也不能创�?/span>Transactions�Q�这也是因�ؓ(f��)有约束条件�?/span>

解决�Ҏ(gu��)��是Transactions负责创徏entry�Q?/span>entry的创建操作仅能由Transactions来访问。但是这��h��怼�(x��)�q�背�U�束�Q?/span>No problem�Q�我们可以定义规则就是：(x��)所有的public operations必须以所有约束条仉��得到满��为结束条件�?/span>

Transactions�q�个概念在实际的业务�pȝ��中是不存在的�Q�它其实是�h造的�Q?/span>artifical�Q�，是�ؓ(f��)了便于数据管理，毕竟我们现在用的�q�是关系型数据库以及(qi��ng)面向对象的设计方法哈�?/span>

Summary Account

注意�q�里Summary Account的记账方式是和业务系�l�不同的。在实际的胦务管理中�Q�我们会(x��)在汇总�̎户和明细账户中分别编制会(x��)计分录（Entry�Q�，而在业务�pȝ��中�ƈ不是�q�样�?/span>,按照Martin的叙�q�ͼ�(x��)

1. The entries of a summary account are derived from the component’s entries in a recursive manner.

2. post entries only to detail accounts not to summary accounts.

Posting Rule

1. 什么是Posting Rules�Q?/span>(��记规则)

Posting rule looks at a particular account and, when it sees an entry, creates another entry.

��单的Posting Rule��是乘以一个因子，如图Figure6.8.但是复杂的，例如计税��p��采用Figure6.9的模式�?/span>

注意�q�也��是��Z��么要引入Individual instance method的原因。（�q�个我也是看�?/span>2遍才明白的啊�Q?/span>

�q�句话很重要�Q?/span>We want the behavior to vary with each individual instance.

所以不能通过�cȝ��承实现�?/span>Individual instance method��是讨论如何实现“the behavior to vary with each individual instance”�?/span>

1. Individual instance method-如何实现��记规则�Q?/span>

1) Singleton Class单一实例

2) Strategy Pattern

3) 使用内部�?/span>case语句

�?/span>Posting Rule上我们要定义一�p�d��的操作�?/span>

�?/span>Posting Rule上定�?/span>computeFor�?/span>ComputeFor包含case语句去调用上面的一�p�d��的操作�?/span>

4) 使用带参数的�Ҏ(gu��)��Q?/span>Parameterized Method�Q?/span>

5) 解释�?/span>Interpreter

最�?/span>Martin�l�出了选择实现�Ҏ(gu��)��的原则。他的首选是�Q?/span>Parameterized Method�?/span>

不过我认为如果是做��品，解释�?/span>Interpreter是不二的选择。因为实际的业务�pȝ��的复杂程度绝不是��M��人在产品开发过�E�中可以惌��到的�Q�最大的灉|��性是�q�求的唯一目标。用开发的复杂性换取实施的灉|��性�?/span>

2. Posting Rules在哪里执�?/span>

原则�Q?/span>Separate the strategy of firing the posting rules from the rules themselves as much as possible to reduce the coupling between these mechanisms.

A. Eager Firing

当触发�̎户中产生一�?/span>entry�Q?/span>posting rules��׃��(x��)被触发执行�?/span>

�?/span>2�U�方式：(x��)

A�Q�在创徏Transaction�?/span>entry的方法中posting rules被触发�?/span>

B�Q��?/span>Observer模式�?/span>Make Posting rules observer of their trigger account.�q�种方式比较复杂�Q�尽量避免��用�?/span>

B. Account-based Firing��Z��账户的触�?/span>

�q�是一�U��g时处理。对应每个�̎��L(f��ng)��护一个未处理交易条目列表�Q�尤光��用�?/span>cyclic accounting system�Q��@环记账系�l�）。每�?/span>account处理一�ơ�?/span>

一定要注意账户的处理顺序�?/span>

C. Posting-rule-based Firing

�?/span>Account-based Firing�怼��Q�只�?/span>Posting rule负责��理未处理交易条目列表。这�U�触发方式比较复杂，��量避免使用哈�?/span>

D. Backward-chained Firing

以当前操作帐��P��processing account�Q��ؓ(f��)输出->扑ֈ�posting rule->再推导出对应�?/span>account�Q�这��是要找出哪个帐戯��发的当前操作帐户�Q?/span>->对这些帐戯��行更�?/span>

E. 如何选择posting rule的执行方式：(x��)

要基于一�?/span>2�Ҏ(gu��)��考虑�Q?/span>

ü Posting rule执行的时�?/span>

ü 希望在何处捕获错�?/span>

Martin对这几种�Ҏ(gu��)��的评��h��Q?/span>

Eager Firing没有灉|��?/span>

Account-based Firing�?/span>Posting-rule-based Firing都具有很好的灉|��性，帐户�l�构��单��用前者，若复杂，则��用后者�?/span>

4. Posting Rules在哪里定�?/span>

两种�Ҏ(gu��)��Q?/span>

1�Q?span style="font: 7pt 'Times New Roman'"> knowledge and operational level�Q?/span>posting rules定义�?/span>account type上�?/span>

2�Q?span style="font: 7pt 'Times New Roman'"> 使用summary account�Q�把posting rules定义�?/span>summary account�Q�所有子帐户也都遵��@同样�?/span>posting rules

对于�q�两�U�不同方法的选择的最主要的因素就是：(x��)the degree of difference in the behavior of the candidate accounts and account types.

Choosing the entry

有三�U�方法：(x��)

1�Q?span style="font: 7pt 'Times New Roman'"> Getting all entries back and then doing a selection

2�Q?span style="font: 7pt 'Times New Roman'"> Providing a selection-specific method

3�Q?span style="font: 7pt 'Times New Roman'"> Using a filter�?/span>Filter��是一个封装了查询query的对象�?/span>Pattern�?/span>Figure6.24的时序图�?/span>

amenglai 2009-04-16 15:02 发表评论

精品国产一二,性视频一区二区三区,亚洲影院一区

《分析模式》读后感

变量和赋�?/span>

isKindof�Q�类型判�?/span>

集合

Enumerating Collections

inject

Dictionary

Code Block

Chapter6 Inventory and Accounting

My comments

Brief Summary

Account and Entry

Transactions

Summary account�Q�汇总�̎�?/span>

Memo account�Q�备注�̎�?/span>

Posting rules�Q�簿记规则）

Choosing entries

Accounting practice pattern: �q�是��Z���l?/span>Posting rules�q�行分类

The source of an entry

Balance sheets and income statements(资��负�����和损益表)

Corresponding account

Specialized account model

Transactions

Summary Account

Posting Rule

Accounting practice pattern: �q�是��Z��l?/span>Posting rules�q�行分类

Balance sheets and income statements(资��负��和损益表)