> Am 08.05.2017 um 01:48 schrieb Igor Mironchik <igor.mironc...@gmail.com>: > > Hi, >>>> Using exceptions in arguments parser is something that just cannot be >>>> justified. >>>> >>> Why not? >> Even in the danger of starting a huge debate about "exceptions vs return >> error code" here are my thoughts about it: >> >> Exceptions should just be used for... well, /exceptional/ cases. >> >> So what would be an "exceptional case" for a command line parser then? >> Certainly not wrongly provided arguments. Humans tend to misspell words all >> the time, so that's "the norm": business as usual for a command line parser >> to validate the input and inform the user appropriately (with a usage help, >> similar spelled commands etc.). Nothing which cries "exception!" here IMHO. >> >> The only thing I could think of in a 10 second brainstorming which could be >> considered "exceptional" is when e.g. "stdin" (or some socket even from >> which to read commands, but even this would be a bordercase, as it could be >> considered "normal" that a socket cannot be opened) cannot be opened for >> reading (which is somewhat a constructed example, as arguments are usually >> passed as input parameters to main() anyway - but you get the idea). >> >> The internet is full of articles - and opinions - about when to use >> exceptions, and when not (and we haven't even touched the topic of >> "unchecked vs checked exceptions" - at least in the Java camp that's all the >> rage ;)). > > I will not start that holly war about what you said.... :) I just say that I > will think about more and more user friendly messages on wrong user input.
Hold on: the one (exceptions vs return error codes) has /nothing/ to do with the other (user-friendly error messages). Just to be on the same page here... > I wanted to simplify a life of a developer and a user of console application. > But developer will be informed about "errors" through the exceptions. Yes, your intentions were clear. But did you just read what I wrote about /when/ to use exceptions? In fact, you're not - necessarily - simplifying "the life of a developer" by using exceptions. Au contraire, you force them to use patterns like RAII (which is mostly a good thing by itself), think about whether their code is "exception-safe" etc. There is probably a reason why completely new languages like Swift come completely without exception handling - which raises interesting questions (pun intended), as the main "GUI framework" (Cocoa/ObjC based) still uses - and throws - exceptions then and when... but that's yet another story ;) Cheers, Oliver _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
