Maybe I missed it, but what was the problem
with just using the .length array property ?
Something about templates, or what was it ?

Where was the $ / keyword *needed*, examples ?

--anders

int[] something(int length, int init)
{
	int[] array;

	array.length = length;
	array[0 .. length - 1] = init;

	return array;
}

The "length" parameter is hidden within the array... meaning, on this line:

	array[0 .. length - 1] = init;

The "length" could mean two different things.  It's only within slices that it's a problem.

In this example, it's not a problem... but it could easily be one.

-[Unknown]


> Maybe I missed it, but what was the problem
> with just using the .length array property ?
> Something about templates, or what was it ?
> 
> Where was the $ / keyword *needed*, examples ?
> 
> --anders

On Fri, 04 Mar 2005 09:47:52 +0100, Anders F Björklund <afb@algonet.se> wrote:
> Maybe I missed it, but what was the problem
> with just using the .length array property ?
> Something about templates, or what was it ?
>
> Where was the $ / keyword *needed*, examples ?

[foo.d]
int length = 5;

void main()
{
  int length = 6;
  char[] s;

  s.length = 7;
  s[0..length-1]; // what is the value of the end index?
}

Regan

Unknown W. Brackets wrote:

> int[] something(int length, int init)
> {
>     int[] array;
> 
>     array.length = length;
>     array[0 .. length - 1] = init;
> 
>     return array;
> }
> 
> The "length" parameter is hidden within the array... meaning, on this line:
> 
>     array[0 .. length - 1] = init;
> 
> The "length" could mean two different things.  It's only within slices that it's a problem.

No, not the overloading... What I meant was:

Why wasn't the above code instead written as:

     array.length = length;
     array[0 .. array.length - 1] = init;

Where is the name of the array not known ?
(in what circumstances, I've heard "templates")

--anders

Forgive me; I indeed misunderstood.

It's not, as far as I know.  Just syntactical sugar... but, it is fairly nice sugar.  Consider:

Airport.getFromHangar(AIRPLANE_747).optionalComponents["seatbelts"][length - 5 .. length]

Okay, strange example, but it's nice to have.  That said, you're right: I don't believe there's any specific need for it.

-[Unknown]


> No, not the overloading... What I meant was:
> 
> Why wasn't the above code instead written as:
> 
>      array.length = length;
>      array[0 .. array.length - 1] = init;
> 
> Where is the name of the array not known ?
> (in what circumstances, I've heard "templates")
> 
> --anders

On Fri, 04 Mar 2005 10:14:27 +0100, Anders F Björklund wrote:


[snip]


> 
> No, not the overloading... What I meant was:
> 
> Why wasn't the above code instead written as:
> 
>       array.length = length;
>       array[0 .. array.length - 1] = init;
> 
> Where is the name of the array not known ?
> (in what circumstances, I've heard "templates")

It is not *needed*. It just makes reading and writing code easier and less costly.

Just as 'for', 'foreach', 'switch', 'while', slices, etc... are not needed, but they sure make code development less troublesome.

-- 
Derek Parnell
Melbourne, Australia
4/03/2005 10:44:05 PM

In article <d0997e$l22$1@digitaldaemon.com>, Unknown W. Brackets says...
>
>Forgive me; I indeed misunderstood.
>
>It's not, as far as I know.  Just syntactical sugar... but, it is fairly nice sugar.  Consider:
>
>Airport.getFromHangar(AIRPLANE_747).optionalComponents["seatbelts"][length - 5 .. length]
>
>Okay, strange example, but it's nice to have.  That said, you're right: I don't believe there's any specific need for it.

Given that C++ and Java have the same issue and neither of those languages have a special 'length' and I've never heard anyone request one, I don't think this use case will come up enough to make the special 'length' worth it. But that's just me...

>> No, not the overloading... What I meant was:
>> 
>> Why wasn't the above code instead written as:
>> 
>>      array.length = length;
>>      array[0 .. array.length - 1] = init;
>> 
>> Where is the name of the array not known ?
>> (in what circumstances, I've heard "templates")
>> 
>> --anders

Derek Parnell wrote:

> It is not *needed*. It just makes reading and writing code easier and less
> costly.

I'm not sure that this whole thread and Kris's problems with
"length" variables qualifies as "less costly", but anyway...

> Just as 'for', 'foreach', 'switch', 'while', slices, etc... are not needed,
> but they sure make code development less troublesome.

Yup, maybe something good can come out of this long debate ?
And that the length var hack somehow can disappear from arrays.

http://www.digitalmars.com/d/changelog.html#new099:
> What's New for D 0.99
> Aug 19, 2004
[...]
> *  Added implicit declaration of length to index and slice expressions.
> This will break existing code if length is used as a variable within [ ]. 

Until then, array.length sounds like the safe bet.
(still waiting for the reason it was introduced ?)

--anders

Unknown W. Brackets wrote:

> It's not, as far as I know.  Just syntactical sugar... but, it is fairly nice sugar.  Consider:
> 
> Airport.getFromHangar(AIRPLANE_747).optionalComponents["seatbelts"][length - 5 .. length]
> 
> Okay, strange example, but it's nice to have.

So just use a temp ? Too much sugar is not good for you, anyway :-)

--anders

Regan Heath wrote:
> On Fri, 04 Mar 2005 09:47:52 +0100, Anders F Björklund <afb@algonet.se>  wrote:
> 
>> Maybe I missed it, but what was the problem
>> with just using the .length array property ?
>> Something about templates, or what was it ?
>>
>> Where was the $ / keyword *needed*, examples ?
> 
> 
> [foo.d]
> int length = 5;
> 
> void main()
> {
>   int length = 6;
>   char[] s;
> 
>   s.length = 7;
>   s[0..length-1]; // what is the value of the end index?
> }
> 
> Regan


Its too bad the with statement doesnt work with arrays:

int []a = new int[100];
int []x;

with(a) x[0..length] = a[0..length];


Looks pretty clean to me.