Re: Function names and lambdas
On 2017-04-07 23:05, Ali Çehreli wrote: Main reason for D not supporting the name-to-pointer mapping? I don't think so because as far as I know this has been the case since very early on but UFCS came very much later. More likely due to properties, i.e. calling functions without parentheses. It's more difficult to know if the function should be called or if the address of the function should be taken. -- /Jacob Carlborg
Re: Function names and lambdas
On 04/07/2017 11:19 AM, Yuxuan Shui wrote:
> On Thursday, 6 April 2017 at 18:45:26 UTC, Ali Çehreli wrote:
>> On 04/06/2017 11:37 AM, Russel Winder via Digitalmars-d-learn wrote:
>>> [...]
>>
>> I think it's just a design choice. C implicitly converts the name of
>> the function to a pointer to that function. D requires the explicit &
>> operator:
>>
>> alias Func = int function(int);
>>
>> int foo(int i) {
>> return i;
>> }
>>
>> void main() {
>> Func[] funcs = [ &foo ];
>> }
>>
>> Close to what you mentioned, name of the function can be used as an
>> alias template parameter:
>>
>> void bar(alias func)() {
>> func(42);
>> }
>>
>> int foo(int i) {
>> return i;
>> }
>>
>> void main() {
>> bar!foo();
>> }
>>
>> Ali
>
> Main reason is probably UFCS.
Main reason for D not supporting the name-to-pointer mapping? I don't
think so because as far as I know this has been the case since very
early on but UFCS came very much later.
Ali
Re: Function names and lambdas
On Thursday, 6 April 2017 at 18:45:26 UTC, Ali Çehreli wrote:
On 04/06/2017 11:37 AM, Russel Winder via Digitalmars-d-learn
wrote:
[...]
I think it's just a design choice. C implicitly converts the
name of the function to a pointer to that function. D requires
the explicit & operator:
alias Func = int function(int);
int foo(int i) {
return i;
}
void main() {
Func[] funcs = [ &foo ];
}
Close to what you mentioned, name of the function can be used
as an alias template parameter:
void bar(alias func)() {
func(42);
}
int foo(int i) {
return i;
}
void main() {
bar!foo();
}
Ali
Main reason is probably UFCS.
Re: Function names and lambdas
On Thu, 2017-04-06 at 11:45 -0700, Ali Çehreli via Digitalmars-d-learn
wrote:
>
[…]
> I think it's just a design choice. C implicitly converts the name of
> the
> function to a pointer to that function. D requires the explicit &
> operator:
One of the dangers of being a bit like and a replacement for another
language is that often people carry ideas over incorrectly, as I have
here.
> alias Func = int function(int);
>
> int foo(int i) {
> return i;
> }
>
> void main() {
> Func[] funcs = [ &foo ];
> }
I just did:
immutable funcs = [tuple(&foo, "foo")];
as I don't need the name of the type, but I do need a string form of
the name of the function.
> Close to what you mentioned, name of the function can be used as an
> alias template parameter:
>
> void bar(alias func)() {
> func(42);
> }
>
> int foo(int i) {
> return i;
> }
>
> void main() {
> bar!foo();
> }
Good to know but for situation here the &foo was what was needed.
--
Russel.
=
Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net
41 Buckmaster Roadm: +44 7770 465 077 xmpp: rus...@winder.org.uk
London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder
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Re: Function names and lambdas
On Thu, 2017-04-06 at 18:45 +, Adam D. Ruppe via Digitalmars-d- learn wrote: > On Thursday, 6 April 2017 at 18:37:51 UTC, Russel Winder wrote: > > I am used to a function name being a reference to the function > > body, cf. lots of other languages. However D rejects: > > > > iterative > > Try > > &iterative > > > > The compiler would probably optimize out a trivial thing anyway, > but &foo should work too in most cases. No don't I look like a real idiot. Of course I should have known that. :-) It works exactly as required. -- Russel. = Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net 41 Buckmaster Roadm: +44 7770 465 077 xmpp: rus...@winder.org.uk London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder signature.asc Description: This is a digitally signed message part
Re: Function names and lambdas
On 04/06/2017 11:37 AM, Russel Winder via Digitalmars-d-learn wrote:
I am used to a function name being a reference to the function body,
cf. lots of other languages. However D rejects:
iterative
as a thing can put in an array, it requires:
(n) => iterative(n)
Presumably this introduces inefficiency at run time? I.e. the extra
level of indirection is not compiled away?
I think it's just a design choice. C implicitly converts the name of the
function to a pointer to that function. D requires the explicit & operator:
alias Func = int function(int);
int foo(int i) {
return i;
}
void main() {
Func[] funcs = [ &foo ];
}
Close to what you mentioned, name of the function can be used as an
alias template parameter:
void bar(alias func)() {
func(42);
}
int foo(int i) {
return i;
}
void main() {
bar!foo();
}
Ali
Re: Function names and lambdas
On Thursday, 6 April 2017 at 18:37:51 UTC, Russel Winder wrote: I am used to a function name being a reference to the function body, cf. lots of other languages. However D rejects: iterative Try &iterative The compiler would probably optimize out a trivial thing anyway, but &foo should work too in most cases.
Function names and lambdas
I am used to a function name being a reference to the function body, cf. lots of other languages. However D rejects: iterative as a thing can put in an array, it requires: (n) => iterative(n) Presumably this introduces inefficiency at run time? I.e. the extra level of indirection is not compiled away? -- Russel. = Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net 41 Buckmaster Roadm: +44 7770 465 077 xmpp: rus...@winder.org.uk London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder signature.asc Description: This is a digitally signed message part
