BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Would something like this be cool? Goto page 1, 2, 3, 4, 5, 6  Next          BorlandTalk.com Forum Index -> Delphi Non-Technical View previous topic :: View next topic   Author Message Msangali Guest Posted: Sun Aug 28, 2005 3:42 pm    Post subject: Would something like this be cool? Hi, Do you think this if SomethingIsNotOK then begin ShowMessage('It cannot be done'); Exit; end; //code continues... could be better expressed this way if SomethingIsNotOK then ExitWithMessage('It cannot be done'); //code continues... Back to top JohnE Guest Posted: Sun Aug 28, 2005 4:06 pm    Post subject: Re: Would something like this be cool? This is similar If SomethingIsNotOk then Raise Exception.Create('It cannot be done'); Back to top Jarle Stabell Guest Posted: Sun Aug 28, 2005 4:13 pm    Post subject: Re: Would something like this be cool? JohnE wrote: Quote: This is similar If SomethingIsNotOk then Raise Exception.Create('It cannot be done'); I don't know about similar, but at least it is superior. :-) Cheers, Jarle Back to top Yannis Guest Posted: Sun Aug 28, 2005 4:24 pm    Post subject: Re: Would something like this be cool? Msangali wrote: Quote: Hi, Do you think this if SomethingIsNotOK then begin ShowMessage('It cannot be done'); Exit; end; //code continues... could be better expressed this way if SomethingIsNotOK then ExitWithMessage('It cannot be done'); //code continues... I consider this code as a patch I do prefare If SomethingIsOK then Code else showMessage('It cannot be done'); This is probably because of my habbits of programming than anything else but I find easier to follow the code when there is a single exit point of a procedure. as for your question it feels the same to me eitherway. Regards Yannis. Back to top Richard Foersom Guest Posted: Sun Aug 28, 2005 5:19 pm    Post subject: Re: Would something like this be cool? Yannis wrote: Quote: This is probably because of my habbits of programming than anything else but I find easier to follow the code when there is a single exit point of a procedure. Thanks Yannis, I agree. Exit smells like goto in disguise. Doei RIF Back to top Jarle Stabell Guest Posted: Sun Aug 28, 2005 5:54 pm    Post subject: Re: Would something like this be cool? Robert Giesecke wrote: Quote: JohnE wrote: This is similar If SomethingIsNotOk then Raise Exception.Create('It cannot be done'); I don't know about similar, but at least it is superior. :-) Yeah, whereas I'd prefer something like this: if SomethingCannotBeDone then raise CannotBeDoneException.Create(); If this situation is so frequent that it warrants its own exception class, I'd probably implement a produre to cast the exception, making the code ending up like: if SomethingCannotBeDone then RaiseCannotBeDone('because'); But then, ECannotBeDone sounds like an abstract class to me, with subclasses like ENotImplementedYet, EProgrammerMadeStupidBug, EUserMadeStupidAction, ESomethingReallyStrangeHappened etc. ;-) Cheers, Jarle Back to top Msangali Guest Posted: Sun Aug 28, 2005 6:16 pm    Post subject: Re: Would something like this be cool? Hi, I know this is a matter of taste, but I like "exit" because with it the code doesn't slide too much to the right and then I have more space on each line. Besides, using exit, I often can put all the necessary tests at the top of a procedure, and, only after them, I write the main branch. IMHO, this make the main branch more readable than putting it in a dense If-Then-Else structure. Regards, Marco "Yannis" <None (AT) noware (DOT) non> wrote Quote: Msangali wrote: Hi, Do you think this if SomethingIsNotOK then begin ShowMessage('It cannot be done'); Exit; end; //code continues... could be better expressed this way if SomethingIsNotOK then ExitWithMessage('It cannot be done'); //code continues... I consider this code as a patch I do prefare If SomethingIsOK then Code else showMessage('It cannot be done'); This is probably because of my habbits of programming than anything else but I find easier to follow the code when there is a single exit point of a procedure. as for your question it feels the same to me eitherway. Regards Yannis. Back to top Msangali Guest Posted: Sun Aug 28, 2005 6:22 pm    Post subject: Re: Would something like this be cool? Hi, Why is it superior? IMHO, creation of a exception is a much more costly operation than just exit. And,.AFAIK, exception handling should be used to, well, handle exceptions, not predictable branches of code. Regards, Marco "Jarle Stabell" <jarle (AT) remove_stuff_dlogikk_spam_kills_email (DOT) com> wrote in message news:4311e28d (AT) newsgroups (DOT) borland.com... Quote: JohnE wrote: This is similar If SomethingIsNotOk then Raise Exception.Create('It cannot be done'); I don't know about similar, but at least it is superior. :-) Cheers, Jarle Back to top Erwien Saputra Guest Posted: Sun Aug 28, 2005 6:33 pm    Post subject: Re: Would something like this be cool? Msangali wrote: Quote: Why is it superior? IMHO, creation of a exception is a much more costly operation than just exit. And,.AFAIK, exception handling should be used to, well, handle exceptions, not predictable branches of code. This is an error handling, you handle an error or an undesireable condition by raising an exception. The exception handling is done by the caller of your method. The code was not clear whether the code was part of UI classes or probably part of some business object classes. If the code is part of business object class, the UI objects can decide whether to display the message, or to do something with it. It may not be a good idea to display a message window, as it requires user interaction to close the message and to exit. Also, the application may not have UI or should not interract with the user (running behind the screen and store the errors to the log). Wien. -- http://blogs.slcdug.org/esaputra Delphi Setting Manager - http://www.codeline.net/DelphiSettingManager Reference Tool - http://www.codeline.net/RefTool Back to top Robert Giesecke Guest Posted: Sun Aug 28, 2005 6:36 pm    Post subject: Re: Would something like this be cool? Quote: JohnE wrote: This is similar If SomethingIsNotOk then Raise Exception.Create('It cannot be done'); I don't know about similar, but at least it is superior. :-) Yeah, whereas I'd prefer something like this: if SomethingCannotBeDone then raise CannotBeDoneException.Create(); @Msangali I don't know what useful something like this could be, as I doubt ShowMessage has any real purose. ;-) --- posted by geoForum on http://delphi.newswhat.com Back to top Msangali Guest Posted: Sun Aug 28, 2005 6:59 pm    Post subject: Re: Would something like this be cool? Hi, Erwien, Sorry if I wasn't clear, I was talking about a code in UI - a button, for instance. That's why I showed the message. The ideia is to warn the user that something didn't happened as expected. If it was a component code or something more down-to-the guts like that, of course, an exception would be the first option. Exceptions are overused sometimes IMHO. I mean, once I saw a code like this (IIRC) try x:=teta/gama; except on EDivByZero do x:=0; end; If you call this routine and gama is 0, the overhead is huge due to the exception raised, AFAIK. This is one reason why I always try to use exceptions only for "external" problems (I/O, databases) and avoid it on other situations. Altough, of course, in this UI example, that would be no impact in performance. Regards, Marco * Is it only me that uses "exit"? :-) Back to top Ivan Cruz Guest Posted: Sun Aug 28, 2005 7:27 pm    Post subject: Re: Would something like this be cool? Msangali wrote: Quote: Hi, Do you think this if SomethingIsNotOK then begin ShowMessage('It cannot be done'); Exit; Oh my god!!! GOTOs are so sixties!!! http://www.acm.org/classics/oct95/ Ivan. Back to top Michael Anonymous Guest Posted: Sun Aug 28, 2005 7:43 pm    Post subject: Re: Would something like this be cool? Msangali wrote: Quote: Do you think this if SomethingIsNotOK then begin ShowMessage('It cannot be done'); Exit; end; //code continues... could be better expressed this way if SomethingIsNotOK then ExitWithMessage('It cannot be done'); //code continues... Yes. Back to top Michael Anonymous Guest Posted: Sun Aug 28, 2005 7:48 pm    Post subject: Re: Would something like this be cool? Ivan Cruz wrote: Quote: Oh my god!!! GOTOs are so sixties!!! http://www.acm.org/classics/oct95/ The original poster used an exit statement not a goto. In any event, I still use gotos for a few things. But I'm one of those types that thinks marijuana might taste good on pizza. After all, some rules are made to be broken. Back to top Erwien Saputra Guest Posted: Sun Aug 28, 2005 9:00 pm    Post subject: Re: Would something like this be cool? Msangali wrote: Quote: Exceptions are overused sometimes IMHO. I mean, once I saw a code like this (IIRC) I tend to use exception whenever applicable. You may want to check Raymond Chen's blog post about exception. It is thought provoking. http://blogs.msdn.com/oldnewthing/archive/2005/01/14/352949.aspx About the exception overhead, I know exception is expensive, but will I sacrifice a possibly more maintainable code for saving some CPU cycles? Unless I can profile it and see significant difference, I won't bother. Quote: * Is it only me that uses "exit"? No. I do it too. :) I find Exit if used properly makes code easier to read. For example: procedure TForm.A (const SomeString : string); begin if SameText (SomeString, 'A') then begin DoSomethingA; Exit; end; if SameText (SomeString, 'B') then begin DoSomethingB; Exit; end; if SameText (SomeString, 'C') then begin DoSomethingC; Exit; end; if SameText (SomeString, 'D') then begin DoSomethingD; Exit; end; end; I pulled that example from nowhere. IMO, that is much cleaner than nested if..else. I do not use Exit if it nested deeper than above. Wien. -- http://blogs.slcdug.org/esaputra Delphi Setting Manager - http://www.codeline.net/DelphiSettingManager Reference Tool - http://www.codeline.net/RefTool Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi Non-Technical All times are GMT Goto page 1, 2, 3, 4, 5, 6  Next Page 1 of 6   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.