欢迎来到天天文库
浏览记录
ID:34494067
大小:218.31 KB
页数:8页
时间:2019-03-06
《a method for the construction of robust class hierarchiesnew》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、AMethodfortheConstructionofRobustClassHierarchiesArneFrickRainerNeumannWolfZimmermann18thJune1996AbstractWeintroduceamethodfortheconstructionofrobustclasshierarchies.Thebaseofthisconstructionisarigorousdenitionofinheritance.Therearefourpossibleinheri
2、tancerelationships.Atleasttwoofthemturnedouttobeimportantinpractice.Accordingtothisforthersttime,conditionsforthecorrectuseofpolymorphismaregiven.Weshowhowinheritancehierarchiescanbeconstructedinasystematicandrigorousway.1IntroductionTheparadigmofobject
3、-orientedprogramminghasprovidedalargenumberofmethodsforthedesignandtheimplementationofapplications,mostofwhichdonotprovideasolidandformalbasisforcorrectnessproofs.Thoughthemethods[1,5]helptodevelopasystem,thereisnosupporttoassertorprovecertainproperties.
4、Onereasonforthisis,thatbasicconceptslikeinheritance,polymorphismandgenericityarenotdeterminedinaformalmanner.Thismakessense,ifoneissalingdesigntools,becausethiswaysomekindoflanguageindependenceiseasiertoreach.ButevenformalmethodslikeObject-Zalsofailbecau
5、seofthislackofformaldenitions.Wethereforehavetorecognize,thataftermorethanonedecadeofobject-orientedmodelingbasicconceptsarenotreallyunderstoodordescribedinamathematicalway.Whatismissing,isamethodforthecorrectdevelopmentofobject-orientedsystems.Although
6、therequirementsneededtoprovidecorrectsystemsorclasslibrarieswereshownin[2],thereisstillneedforamethodforthesystematicconstructionofsuchsystems.Thetasknowistoconstructamethodwhereacorrectdevelopmentprocessleadstoacorrectsystem.MeyersDesignbyContract[4]iso
7、nesteptowardsthisgoal.Linkagebetweenobjectsisdescribedbypre{/postconditionsandinvariants.Butstilltheuseofinheritance,polymorphismorgenericitymayleadtoincorrectsystems{theglobalsystemcorrectnessmaybedestroyedbylocallycorrectclasses.Thispapernowdescribes,h
8、owobject-orientedsystemsmaybedesignedsothatviolationsoftheglobalsystemcorrectnesswillbedetectedatcompilationtime.Thismethodismentionednottoreplacebuttosupportexistingmethodsbygivenformaldescriptionsofbasicconcepts.Theremai
此文档下载收益归作者所有