Named return values are perfectly fine, and I agree, probably should not be discouraged. For example, which is easier to write documentation for?
func Run(cmd string) ([]byte, []byte, error)
func Run(cmd string) (stdout, stderr []byte, _ error)
What is not good is the following function:
func Foo() (err error) {
if err := someFunc(); err != nil {
return // Why do I always get a nil error?!?!
}
return
}
This is a* naked return* and that is what is bad, not that you named your
return values. This version is fine:
func Foo() (err error) {
if err := someFunc(); err != nil {
return err
}
return nil
}
As there is no doubt on what is being returned. And as mentioned earlier,
named returns are very useful in defers:
func Foo(path string) (err error) {
w, err := os.Create(path, 0644)
if err != nil {
return err
}
defer func() {
if cerr := w.Close(); cerr != nil && err == nil {
err = cerr
}
}()
...
}
Again, named return values are fine and cause no problems, but naked
returns should never have been part of the language (at first they seem
useful and cool, but in the end, they cause more problems than they solve).
On Tue, Feb 21, 2017 at 8:25 PM, <prades.m...@gmail.com> wrote:
> Named returns are actually quite useful with panics :
>
> https://play.golang.org/p/ZdoZJBN0T1
>
>
> Le mardi 21 février 2017 23:13:11 UTC+1, Ian Lance Taylor a écrit :
>>
>> On Tue, Feb 21, 2017 at 1:46 PM, <andrew.p...@gmail.com> wrote:
>> > Seems like named returns + if/for/switch initializers = a shadowing
>> > nightmare. I wish the Go compiler emitted a loud warning on shadowing,
>> as
>> > this is a dangerously subtle problem out there.
>>
>> Yes, named returns may have been a mistake. Only use them in very
>> very short functions.
>>
>> Ian
>>
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