[swift-evolution] Annotation of Warnings/Errors

[Saagar Jha]

+1, provided these differences are ignored if the user manually builds a
project. Hopefully this takes some of the load off of SourceKitService.
On Wed, Jan 25, 2017 at 16:07 Jonathan Hull via swift-evolution <
swift-evolution at swift.org> wrote:

> Yes.  It would stick once it appears (until it is fixed, of course)
>
> On Jan 25, 2017, at 4:02 PM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
>
> I didn't read the proposal to mean vanish; rather, just lazily displayed
> until some condition, but then permanently there once it shows up. It
> really is annoying to be constantly reminded you haven't used a variable
> when you've literally just declared it. Once you've left the scope once,
> it's fair to have that warning stay there whether or not you click back.
> On Wed, Jan 25, 2017 at 17:59 Karl Wagner via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>
> > On 26 Jan 2017, at 00:46, Jonathan Hull via swift-evolution <
> swift-evolution at swift.org> wrote:
> >
> > One of the biggest issues that I saw while teaching Swift to newbies
> (most had not programmed before) is confusion based on the early
> warnings/errors that swift/xcode gives you as they type.  What would happen
> is that they would type a variable, and it would say… “You haven’t used
> this variable” and so they would just click the fixit because they trust
> the compiler more than they trust themselves.  This would lead to a point
> where they were very confused because some of the code was code they had
> thought through, and some of it was changed by random fixits in ways they
> didn’t understand… and so it would lead to more errors/fixits until they
> had errors which couldn’t be fixed.
> >
> > By the end of the semester they had learned to ignore the warnings until
> they were finished, but it took a couple of months to get there, and was a
> big deterrent to new users… (Also, learning to ignore warnings ignorer to
> use a system seems like an anti-pattern)
> >
> > I have a good friend who is an expert perl programmer who tried Swift
> and eventually gave up because he couldn’t figure out which errors to
> ignore (and which might just disappear a minute later) and which he needed
> to pay attention to. He was overwhelmed by the sheer number, and they
> didn’t seem trustworthy to him (“Swift is full of lies!” he would say of
> the warnings… which is a mantra I find myself parroting when I get those
> appearing/disappearing errors).
> >
> >
> > To fix this, I propose adding a way to annotate warnings/errors to say
> how immediate they need to be:
> > • Immediate - This error should always be shown
> > • DifferentLine - This error should only be shown once the cursor is on
> a different line
> > • DifferentScope - This error should only be shown once the cursor is in
> a different scope from this line
> > • DifferentFunction - This error should only be shown once the cursor is
> in a different function
> >
> > So the “You haven’t used this variable” warning would be marked
> .differentScope, meaning that it would only show up once you had clicked
> away from the scope. The reason for this is that while you are in the same
> scope, it is fairly likely that you are still going to use the variable… so
> the warning is premature. Once I have left the scope, it makes sense to
> warn me.
> >
> > Similarly, the “You need a return value” error would be marked
> .differentFunction because you are likely to add one while typing the
> function. But a type mismatch with the return value would either be
> .immediate or .differentLine because you have made an error that isn’t
> likely to be fixed with more typing on other lines.
> >
> > I think this will cut way down on the number of warnings/errors that
> need to be ignored, which should increase trust in the system overall.
> >
> > To be clear, I am only proposing adding the annotation to Swift
> (probably with a default of .differentLine). The compiler would not repress
> the warning/error itself… just vend it with a way to retrieve the
> annotation.  IDE makers like Apple/Xcode would then be free to use that
> extra information in their UI if desired.
> >
> > Thanks,
> > Jon
> > _______________________________________________
> > swift-evolution mailing list
> > swift-evolution at swift.org
> > https://lists.swift.org/mailman/listinfo/swift-evolution
>
> Having warnings and errors vanish and then reappear as you click in/out of
> function seems far more confusing to me. Is there any other language/IDE
> that does things that way?
>
> - Karl
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20170126/caa71153/attachment.html>