I agree with @robert.
The compiler cannot guarantee that the function will always return a value.
Even though we can see that the loop will eventually *return i* value, the
compiler isn't able to make this determination statically.
Compile doesn't complain about the following code. I'm no expert, but I
think this is strictly compiler behavior:
func myfunc() int {
for i := 0; ; i++ {
if i > 8 {
return i
}
}
}
But the following code will not compile.
func myfunc() int {
for i := 0; i <= 9; i++ {
if i > 8 {
return i
}
}
}
To fix that (for didactic purposes only), we can add a return statement
after the loop (which will never be reached, but satisfies the compiler):
func myfunc() int {
for i := 0; true; i++ {
if i > 8 {
return i
}
}
return 0 // This line is unreachable but satisfies the compiler
}
If anyone knows more about this behavior, I would be happy to learn more.
Cleberson
Em sexta-feira, 11 de outubro de 2024 às 19:34:46 UTC-3, Ian Lance Taylor
escreveu:
> On Fri, Oct 11, 2024 at 3:07 PM robert engels <[email protected]>
> wrote:
> >
> > true is an expression, the compiler doesn’t inspect that it is a
> constant expression, thus you need the return statement
>
> The exact rules can be seen at
> https://go.dev/ref/spec#Terminating_statements.
>
> Ian
>
>
>
> > > On Oct 11, 2024, at 4:57 PM, Pierpaolo Bernardi <[email protected]>
> wrote:
> > >
> > > Hello,
> > >
> > > the following code works as I expect:
> https://go.dev/play/p/pjKqpZyTU0d
> > >
> > > However, if I change line 15 from
> > >
> > > for i := 0; ; i++ {
> > >
> > > to
> > >
> > > for i := 0; true; i++ {
> > >
> > > it does not compile. In my understanding the two should be equivalent,
> > > but they are not. Maybe I'm missing a simple explanation?
> > >
> > > --
> > > You received this message because you are subscribed to the Google
> Groups "golang-nuts" group.
> > > To unsubscribe from this group and stop receiving emails from it, send
> an email to [email protected].
> > > To view this discussion on the web visit
> https://groups.google.com/d/msgid/golang-nuts/CANY8u7F3pV_FX3jQHRz%2BOpmrPN0qb6-2-NAwzQYNRe9Qq18D8A%40mail.gmail.com
> .
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "golang-nuts" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to [email protected].
> > To view this discussion on the web visit
> https://groups.google.com/d/msgid/golang-nuts/0E9E12CB-EF17-4977-BA5A-07704C01DAB9%40ix.netcom.com
> .
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/golang-nuts/64a8d187-115f-41ea-9a72-ddfe52fdb8dan%40googlegroups.com.
