Hello,
After a long break, I go back to reading Go Spec.
In the section "Expression statements" we read that "The following built-in
functions are not permitted in statement context:
append cap complex imag len make new real
unsafe.Add unsafe.Alignof unsafe.Offsetof unsafe.Sizeof unsafe.Slice
h(x+y)
f.Close()
<-ch
(<-ch)
len("foo") // illegal if len is the built-in function"
Are things following "h(x+y)" also forbidden in the statement context? This
part of spec isn't specially clear in my opinion.
Best regards,
Kamil
poniedziałek, 12 czerwca 2023 o 02:02:27 UTC+2 Rob Pike napisał(a):
> Although the sentence is OK as it stands, the section should be tweaked a
> bit. One of the examples there (myString(0x65e5)) is valid Go but vet
> rejects it, as part of the move towards disallowing this conversion, which
> was there mostly for bootstrapping the libraries.
>
> -rob
>
>
> On Mon, Jun 12, 2023 at 3:10 AM 'Axel Wagner' via golang-nuts <
> [email protected]> wrote:
>
>> Ah, the spec does actually say:
>>>
>>> Converting a signed or unsigned integer value to a string type yields a
>>> string containing the UTF-8 representation of the integer. Values outside
>>> the range of valid Unicode code points are converted to "\uFFFD".
>>
>>
>> Personally, I think this is fine as is. I think people understand what
>> happens from these two sentences.
>>
>> On Sun, Jun 11, 2023 at 7:02 PM Axel Wagner <[email protected]>
>> wrote:
>>
>>> I'm not entirely sure. I don't think your phrasing is correct, as it
>>> doesn't represent what happens if the integer value exceeds the range of
>>> valid codepoints (i.e. if it needs more than 32 bits to represent). That
>>> being said, the sentence as is also isn't really precise about it. From
>>> what I can tell, the result is not valid UTF-8 in any case.
>>>
>>> I think it might make sense to file an issue about this, though in
>>> general that conversion is deprecated anyway and gets flagged by `go vet`
>>> (and `go test`) because it is not what's usually expected. So I'm not sure
>>> how important it is to get this exactly right and understandable.
>>>
>>>
>>> On Sun, Jun 11, 2023 at 5:17 PM Kamil Ziemian <[email protected]>
>>> wrote:
>>>
>>>> I have some hair splitting question. In the "Conversions to and from a
>>>> string type" we read:
>>>> "Converting a signed or unsigned integer value to a string type yields
>>>> a string containing the UTF-8 representation of the integer."
>>>>
>>>> Would it be more corrected to say, that conversion from integer to
>>>> string gives you UTF-8 representation of code point described by value of
>>>> the integer? Or maybe it is indeed representation of integer described by
>>>> UTF-8 specification?
>>>>
>>>> Best regards,
>>>> Kamil
>>>> czwartek, 28 października 2021 o 19:33:27 UTC+2 Kamil Ziemian
>>>> napisał(a):
>>>>
>>>>> Hello,
>>>>>
>>>>> From what I understand proper Gopher read at least one time "The Go
>>>>> Programming Language Specification" (https://golang.org/ref/spec) and
>>>>> now I need to read it too.
>>>>>
>>>>> I learn something of Extended Backus-Naur Form to understand it, so if
>>>>> I say something stupid beyond belief, I hope you will forgive me. In the
>>>>> first part "Notation" (https://golang.org/ref/spec#Notation) I
>>>>> believe that I understand meaning of all concepts except of
>>>>> "production_name". On one hand "production_name" means that it is name of
>>>>> the production, not rocket science here. On the other, after reading
>>>>> about
>>>>> EBNF I feel that I should have more information about it. Can you explain
>>>>> it to me?
>>>>>
>>>>> Again I'm new to EBNF, so maybe this is stupid question.
>>>>>
>>>>> Best
>>>>> Kamil
>>>>>
>>>>> --
>>>> 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/06347585-fd2c-4bfa-9527-3439389c6414n%40googlegroups.com
>>>>
>>>> <https://groups.google.com/d/msgid/golang-nuts/06347585-fd2c-4bfa-9527-3439389c6414n%40googlegroups.com?utm_medium=email&utm_source=footer>
>>>> .
>>>>
>>> --
>> 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/CAEkBMfHaG8bYNLvLERu0-ad57wpoWsiB%2BFC5asyKA7FH6%2BvgZw%40mail.gmail.com
>>
>> <https://groups.google.com/d/msgid/golang-nuts/CAEkBMfHaG8bYNLvLERu0-ad57wpoWsiB%2BFC5asyKA7FH6%2BvgZw%40mail.gmail.com?utm_medium=email&utm_source=footer>
>> .
>>
>
--
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/a2031526-c215-4594-8da3-2aea38d95d85n%40googlegroups.com.
