Abstraheren van modellen

Transcription

1 Department of Computer Science SOM - Geert DelanoteSoftware Development Methodology Abstraheren van modellen Geert Delanote 29 juni 2006 Geert.Delanote@cs.kuleuven.be Overzicht # Operatie Operatie Abstracte methode Afhankelijkheden tussen gebeurtenissen Partiële properties Ideeën => Niets is (volledig) uitgewerkt! 2 1

2 # Operatie (1/8) Query 1 : De (verschillende) lezers van een boek. Query 2 : De (verschillende) boeken die iemand gelezen heeft. Model Met properties Met reïficatie Met # operatie 3 # Operatie (2/8) Model met properties nbloans:natural latestloan:date totalloanperiod:duration loan(period:duration, reader:):void readers():set of * * reader Context ::loan(period:duration, reader:) : void post: self.nbloans = self.nbloans@pre + 1 post: self.latestloan = now post: self.totalloanperiod = self.totalloanperiod@pre + period post: self.reader = self.reader@pre union {reader} Context ::nbloans() : NATURAL post: result = self.nbloans Context ::readers():set of post: result = self.reader Con text ::latestloan() : DATE pre: self.nbloans > 0 post: result = self.latestloan Con text ::avgloanperiod() : DURATION post: result = if self.nbloans = 0 then 0 else self.totalloanperiod/self.nbloans 4 2

3 # Operatie (3/8) Model met reïficatie loan(period:duration, reader:):void readers():set of 1 * Loan period:duration * 1 reader Context ::nbloans() : NAT URAL post: result = self.loan->size() Context ::latestloan() : DAT E pre: self.loan->notempty() post: result = self.loan.cre ationtime->ma x() Context ::avgl oanpe riod : DURATION post: result = self.loan.period->avg() Context ::readers : Set of post: result = self.loan.rea der->a sset() gereïficeerde event is existentiëel afhankelijk van elk argument 5 # Operatie (4/8) Model met # operatie loan(period:duration,reader:):void readers():set of Context ::nbloans() : NATURAL post: result = self#loan()->size() Context ::latestloan() : DATE pre: self#loan()->notempty() post: result = self#loan().executiontime->max() Context ::avgloanperiod() : DURATION post: result = self#loan().period->avg() Context ::readers() : Set of post: result = self#loan().reader->asset() Dependency Low coupling 6 3

4 # Operatie (5/8) Model met properties nbloans:natural latestloan:date totalloanperiod:duration loan(period:duration, reader:):void readers():set of * * reader books() : Set of Context ::books() : Set of post: result = self.book Context ::loan(period:duration, reader:) : void post: self.nbloans = self.nbloans@pre + 1 post: self.latestloan = now post: self.totalloanperiod = self.totalloanperiod@pre + period post: self.reader = self.reader@pre union {reader} Context ::nbloans() : NATURAL post: result = self.nbloans Context ::readers():set of post: result = self.reader Con text ::latestloan() : DATE pre: self.nbloans > 0 post: result = self.latestloan Con text ::avgloanperiod() : DURATION post: result = if self.nbloans = 0 then 0 else self.totalloanperiod/self.nbloans 7 # Operatie (6/8) Model met reïficatie loan(period:duration, reader:):void readers():set of 1 * Loan period:duration * 1 reader books() : Set of Context ::nbloans() : NAT URAL post: result = self.loan->size() Context ::latestloan() : DAT E pre: self.loan->notempty() post: result = self.loan.cre ationtime->ma x() Context ::books() : Set of post: result = self.loan.book->asset() Context ::avgl oanpe riod : DURATION post: result = self.loan.period->avg() Context ::readers : Set of post: result = self.loan.rea der->a sset() 8 4

5 # Operatie (7/8) Model met # operatie loan(period:duration,reader:):void readers():set of Context ::nbloans() : NATURAL post: result = self#loan()->size() Context ::books() : Set of Context ::latestloan() : DATE post: result = {b: b#loan()->select(reader=self)->notempty()} pre: self#loan()->notempty() post: result = self#loan().executiontime->max() Context ::avgloanperiod() : DURATION post: result = self#loan().period->avg() Context ::readers() : Set of post: result = self#loan().reader->asset() Context ::books(person:) : Set of post: result = {b: b#loan()->select(reader=person)->notempty()} Low coupling 9 # Operatie (8/8) Research issues Regels formuleren Welke artificiële objecten wegwerken? Transformatie van statische queries Model met # operatie beter? Low coupling 10 5

6 Archief loan(period:duration,reader:):void readers():set of Context ::nbloans() : NATURAL post: result = self#loan()->size() Context ::latestloan() : DATE pre: self#loan()->notempty() post: result = self#loan().executiontime->max() Context ::avgloanperiod() : DURATION post: result = self#loan().period->avg() Context ::readers() : Set of post: result = self#loan().reader->asset() Populatie? º Archief? Populatie + archief? º Operatie Opvragen van een eigenschap van een object op een gegeven tijdstip Voorbeeld Gewicht (leeftijd) vaneen persoonop het tijdstip van uitlening Model Met properties Met reïficatie Met # operatie 12 6

7 @ Operatie Model met properties Collectie tupels <new weight,time> bijhouden Postconditie vansetweight() Operatie Model met reïficatie 1 1..* WeightAmount weight:mass time:time 14 7

8 @ Operatie Model operatie weight:mass marry(p:):void getweightat(t:time):mass getweightatmarriage():mass marriagedate():time Context ::getweightat(t:time):mass post: result = self@t.getweight() Context ::getweightatmarriage():mass pre: self#marry()->size() = 1 post: result = self@(self.marriagedate).getweight() Context ::marriagedate():time pre: self#marry()->size() = 1 post: result = self#marry().executiontime 15 Abstracte methode (1/6) Model met properties balance:moneyamount withdraw(amount:moneyamount):void deposit(amount:moneyamount):void transferto(amount:moneyamount, target:):void getbalance():moneyamount Context ::withdraw(amount:moneyamount):void post: self.balance = self.balance@pre - amount Context ::deposit(amount:moneyamount):void post: self.balance = self.balance@pre + amount Context ::transferto(amount:moneyamount,target:):void pre: self<>target post: self.balance = self.balance@pre - amount post: target.balance = target.balance@pre + amount 16 8

9 Abstracte methode (2/6) Model met reïficatie Transaction 1 * amount:moneyamount 1 * TransferTo Withdraw Deposit 17 Abstracte methode (3/6) Model met abstracte methode transaction(amount:moneyamount):void withdraw():void deposit():void transferto(target:):void Context ::transferto(target:):void pre: self<>target 18 9

10 Abstracte methode (4/6) Model met properties : getbalance() balance:moneyamount withdraw(amount:moneyamount):void deposit(amount:moneyamount):void transferto(amount:moneyamount, target:):void getbalance():moneyamount Context ::withdraw(amount:moneyamount):void post: self.balance = self.balance@pre - amount Context ::deposit(amount:moneyamount):void post: self.balance = self.balance@pre + amount Context ::transferto(amount:moneyamount,target:):void pre: self<>target post: self.balance = self.balance@pre - amount post: target.balance = target.balance@pre + amount 19 Abstracte methode (5/6) Model met reïficatie : getbalance() getbalance():moneyamount Transaction 1 * amount:moneyamount getdelta():moneyamount 1 * TransferTo Withdraw Deposit Context ::getbalance():moneyamount post: result = self.transaction.getdelta()->sum()+self.transferto.getamount()->sum() Context Withdraw::getDelta():MoneyAmount post: result = -self.getamount() Context Deposit::getDelta():MoneyAmount post: result = self.getamount() Context TransferTo::getDelta():MoneyAmount post: result = -self.getamount() Specificatie onafhankelijk van de subklassen 20 10

11 Abstracte methode (6/6) Model met abstracte methode : getbalance() transaction(amount:moneyamount):void withdraw():void deposit():void transferto(target:):void Context ::transferto(target:):void pre: self<>target Context ::getbalance():moneyamount post: self#deposit().amount->sum() - self#withdraw().amount->sum() - self#transferto().amount->sum() + {tr:transaction tr.target=self}.amount->sum() Specificatie afhankelijk van concrete methodes Context ::getbalance():moneyamount post: self#transaction().delta->sum() + {tr:transaction tr.target=self}.amount->sum() delta is een abstracte eigenschap van transaction() 21 Afhankelijkheden tussen gebeurtenissen Een boek kan pas teruggebracht worden na uitlening loan(period:duration):void return():void 22 11

12 Afhankelijkheden tussen gebeurtenissen isloaned return() loan() isreturned loan() destroy() destroy() destroy() Initial State Final State 23 Afhankelijkheden tussen gebeurtenissen Loan Return loan(period:duration):void return():void * period:duration return():void

13 Partiële properties 1 *? limit:moneyamount increaselimit():void? transferto(a:moneyamount,t:):void Partiële property Partiële event Partiëel associatie eind Savings Universal limit:moneyamount transferto(a:moneyamount,t:):void 25 Besluit Klassificatie Abstracties # Operatie Abstracte methode Afhankelijkheden tussen Operatie Lagen Partiële properties Notatie voor vaak voorkomend patroon Archief 26 13