What do you think about:

class Foo {

   int a;
   float b;

   this( member a, member b ) {

   }

}

instead of:

class Foo {

   int a;
   float b;

   this( int a, float b ) {
      this.a = a;
      this.b = b;
   }

}

Penguin wrote:
> What do you think about:
> 
> class Foo {
> 
>    int a;
>    float b;
> 
>    this( member a, member b ) {
> 
>    }
> 
> }
> 
> instead of:
> 
> class Foo {
> 
>    int a;
>    float b;
> 
>    this( int a, float b ) {
>       this.a = a;
>       this.b = b;
>    }
> 
> }

I don't know that saving a few (very simple) lines of code is worth adding a new keyword and magic behaviour to ctor arguments.

If you really wanted to just do that, you could probably write a mixin to take care of it.

  -- Daniel

"Daniel Keep" <daniel.keep.lists@gmail.com> wrote in message news:gt159p$1bq0$1@digitalmars.com...
>
>
> Penguin wrote:
>> What do you think about:
>>
>> class Foo {
>>
>>    int a;
>>    float b;
>>
>>    this( member a, member b ) {
>>
>>    }
>>
>> }
>>
>> instead of:
>>
>> class Foo {
>>
>>    int a;
>>    float b;
>>
>>    this( int a, float b ) {
>>       this.a = a;
>>       this.b = b;
>>    }
>>
>> }
>
> I don't know that saving a few (very simple) lines of code is worth adding a new keyword and magic behaviour to ctor arguments.
>
> If you really wanted to just do that, you could probably write a mixin to take care of it.
>

I just happen to already have such a thing in my bag-o-tricks. See attachment.

Usage:
----
mixin(initMember!(someVar));
mixin(initMember!(a, b, c));
----

Turns Into:
----
this.someVar = someVar;
this.a = a;
this.b = b;
this.c = c;
----

Nick Sabalausky wrote:
> "Daniel Keep" <daniel.keep.lists@gmail.com> wrote in message news:gt159p$1bq0$1@digitalmars.com...
>>
>> Penguin wrote:
>>> What do you think about:
>>>
>>> class Foo {
>>>
>>>    int a;
>>>    float b;
>>>
>>>    this( member a, member b ) {
>>>
>>>    }
>>>
>>> }
>>>
>>> instead of:
>>>
>>> class Foo {
>>>
>>>    int a;
>>>    float b;
>>>
>>>    this( int a, float b ) {
>>>       this.a = a;
>>>       this.b = b;
>>>    }
>>>
>>> }
>> I don't know that saving a few (very simple) lines of code is worth adding a new keyword and magic behaviour to ctor arguments.
>>
>> If you really wanted to just do that, you could probably write a mixin to take care of it.
>>
> 
> I just happen to already have such a thing in my bag-o-tricks. See attachment.
> 
> Usage:
> ----
> mixin(initMember!(someVar));
> mixin(initMember!(a, b, c));
> ----
> 
> Turns Into:
> ----
> this.someVar = someVar;
> this.a = a;
> this.b = b;
> this.c = c;
> ----
> 
> 
> 

I _also_ have something for this for Phobos (in tools.base), but it's intended for simple constructors.

class Foo {
  int a; float b;
  mixin This!("a, b");
}

Or to add some instruction: mixin This!("a; #b = 0f; ");

Or to add a super call and defaults: mixin This!("a, super(b=0f)");

downs Wrote:

> Nick Sabalausky wrote:
> > "Daniel Keep" <daniel.keep.lists@gmail.com> wrote in message news:gt159p$1bq0$1@digitalmars.com...
> >>
> >> Penguin wrote:
> >>> What do you think about:
> >>>
> >>> class Foo {
> >>>
> >>>    int a;
> >>>    float b;
> >>>
> >>>    this( member a, member b ) {
> >>>
> >>>    }
> >>>
> >>> }
> >>>
> >>> instead of:
> >>>
> >>> class Foo {
> >>>
> >>>    int a;
> >>>    float b;
> >>>
> >>>    this( int a, float b ) {
> >>>       this.a = a;
> >>>       this.b = b;
> >>>    }
> >>>
> >>> }
> >> I don't know that saving a few (very simple) lines of code is worth adding a new keyword and magic behaviour to ctor arguments.
> >>
> >> If you really wanted to just do that, you could probably write a mixin to take care of it.
> >>
> > 
> > I just happen to already have such a thing in my bag-o-tricks. See attachment.
> > 
> > Usage:
> > ----
> > mixin(initMember!(someVar));
> > mixin(initMember!(a, b, c));
> > ----
> > 
> > Turns Into:
> > ----
> > this.someVar = someVar;
> > this.a = a;
> > this.b = b;
> > this.c = c;
> > ----
> > 
> > 
> > 
> 
> I _also_ have something for this for Phobos (in tools.base), but it's intended for simple constructors.
> 
> class Foo {
>   int a; float b;
>   mixin This!("a, b");
> }
> 
> Or to add some instruction: mixin This!("a; #b = 0f; ");
> 
> Or to add a super call and defaults: mixin This!("a, super(b=0f)");


but this is something the compiler should really be dealing with, it's such a common programming practice (the fact so many people have their own hacks for it is testament to this)

i think it's worth a new keyword

"Penguin" <davidcollien@gmail.com> > 
> class Foo {
>   int a;
>   float b;
>   this( member a, member b ) {
>   } }

Why the keyword ?

Why not just:   this(a,b) {  } ?

DisForDave wrote:
> downs Wrote:
> 
>> Nick Sabalausky wrote:
>>> "Daniel Keep" <daniel.keep.lists@gmail.com> wrote in message news:gt159p$1bq0$1@digitalmars.com...
>>>> Penguin wrote:
>>>>> What do you think about:
>>>>>
>>>>> class Foo {
>>>>>
>>>>>    int a;
>>>>>    float b;
>>>>>
>>>>>    this( member a, member b ) {
>>>>>
>>>>>    }
>>>>>
>>>>> }
>>>>>
>>>>> instead of:
>>>>>
>>>>> class Foo {
>>>>>
>>>>>    int a;
>>>>>    float b;
>>>>>
>>>>>    this( int a, float b ) {
>>>>>       this.a = a;
>>>>>       this.b = b;
>>>>>    }
>>>>>
>>>>> }
>>>> I don't know that saving a few (very simple) lines of code is worth adding a new keyword and magic behaviour to ctor arguments.
>>>>
>>>> If you really wanted to just do that, you could probably write a mixin to take care of it.
>>>>
>>> I just happen to already have such a thing in my bag-o-tricks. See attachment.
>>>
>>> Usage:
>>> ----
>>> mixin(initMember!(someVar));
>>> mixin(initMember!(a, b, c));
>>> ----
>>>
>>> Turns Into:
>>> ----
>>> this.someVar = someVar;
>>> this.a = a;
>>> this.b = b;
>>> this.c = c;
>>> ----
>>>
>>>
>>>
>> I _also_ have something for this for Phobos (in tools.base), but it's intended for simple constructors.
>>
>> class Foo {
>>   int a; float b;
>>   mixin This!("a, b");
>> }
>>
>> Or to add some instruction: mixin This!("a; #b = 0f; ");
>>
>> Or to add a super call and defaults: mixin This!("a, super(b=0f)");
> 
> 
> but this is something the compiler should really be dealing with, it's such a common programming practice (the fact so many people have their own hacks for it is testament to this)
> 
> i think it's worth a new keyword

But that's the point - the language is powerful enough that the hacks work fine.

No _need_ for a keyword.

carlos smith:
> Why the keyword ?
> Why not just:   this(a,b) {  } ?

Please, lets not mud the language too much for a small syntax gain.
(What may be added to D is a syntax to create getters/setters in a simple and short way. We have discussed this in the past, C#4 shows a good starting point for this).

Bye,
bearophile

Do people really like such code and not cringe over how unclean and inelegant it is? Maybe it's just me...

On Sun, Apr 26, 2009 at 9:02 AM, bearophile <bearophileHUGS@lycos.com> wrote:
> carlos smith:
>> Why the keyword ?
>> Why not just:   this(a,b) {  } ?
>
> Please, lets not mud the language too much for a small syntax gain.

*snort*

Wait a second, who's the one saying this?