If it is possible, then could someone point me to where it's documented?  Or show me an example of how?

Thank you.

Charles D Hixson wrote:
> If it is possible, then could someone point me to where it's
> documented?  Or show me an example of how?
> 
> Thank you.

Do you mean like this?

class MyMatrix
{
   float opIndex(uint i, uint j)
   {
      return values[i][j];
   }

   float opIndexAssign(float val, uint i, uint j)
   {
      values[i][j] = val;
   }
}

MyMatrix mat = new mat;
mat[0,0] = 0.0f;
float f = mat[0,0];

Mike Parker wrote:
> Charles D Hixson wrote:
>> If it is possible, then could someone point me to where it's documented?  Or show me an example of how?
>>
>> Thank you.
> 
> Do you mean like this?
> 
> class MyMatrix
> {
>    float opIndex(uint i, uint j)
>    {
>       return values[i][j];
>    }
> 
>    float opIndexAssign(float val, uint i, uint j)
>    {
>       values[i][j] = val;
>    }
> }
> 
> MyMatrix mat = new mat;
> mat[0,0] = 0.0f;
> float f = mat[0,0];
Thank you, yes.

I was certain that wouldn't work, so I was asking about something else...but if that works it does precisely what I wanted better than custom properties would.

Although... well, I was asking about something that would look more like:

class MyMatrix
{
   float at(uint i, uint j)
   {
      return values[i][j];
   }

   float at(float val, uint i, uint j)
   {
      values[i][j] = val;
      return val;  //  Not sure about this line
   }
}

MyMatrix mat = new mat;
mat.at(0,0) = 0.0f;
float f = mat.at(0,0);

where the property is "at".  Knowing this would still be
useful, as I might some time want to access things via more
than one method (imagine I had sorted indexes, and was
retrieving the same thing sometimes by name and sometimes by
date, and occasionally by record number).
Still, if this works for opIndexAssign, it probably works
for all properties.

Charles D Hixson wrote:
> Mike Parker wrote:
> 
>>Charles D Hixson wrote:
>>
>>>If it is possible, then could someone point me to where it's
>>>documented?  Or show me an example of how?
>>>
>>>Thank you.
>>
>>Do you mean like this?
>>
>>class MyMatrix
>>{
>>   float opIndex(uint i, uint j)
>>   {
>>      return values[i][j];
>>   }
>>
>>   float opIndexAssign(float val, uint i, uint j)
>>   {
>>      values[i][j] = val;
>>   }
>>}
>>
>>MyMatrix mat = new mat;
>>mat[0,0] = 0.0f;
>>float f = mat[0,0];
> 
> Thank you, yes.
> 
> I was certain that wouldn't work, so I was asking about
> something else...but if that works it does precisely what I
> wanted better than custom properties would.
> 
> Although... well, I was asking about something that would
> look more like:
> 
> class MyMatrix
> {
>    float at(uint i, uint j)
>    {
>       return values[i][j];
>    }
> 
>    float at(float val, uint i, uint j)
>    {
>       values[i][j] = val;
>       return val;  //  Not sure about this line
>    }
> }
> 
> MyMatrix mat = new mat;
> mat.at(0,0) = 0.0f;
> float f = mat.at(0,0);
> 
> where the property is "at".  Knowing this would still be
> useful, as I might some time want to access things via more
> than one method (imagine I had sorted indexes, and was
> retrieving the same thing sometimes by name and sometimes by
> date, and occasionally by record number).
> Still, if this works for opIndexAssign, it probably works
> for all properties.

Note that float vals[][] in D is actually a jagged array.
I think it would be a better idea to store the matrix internally as a one-dimensional array.

Hasan Aljudy wrote:
> 
> 
> Charles D Hixson wrote:
>> Mike Parker wrote:
>>
>>> Charles D Hixson wrote:
>>>
>>>>...
> Note that float vals[][] in D is actually a jagged array.
> I think it would be a better idea to store the matrix internally as a
> one-dimensional array.
> 
I'm sure you're right.  I'd planned to allocate a static array at run time, but apparently that only works for one dimensional arrays...in which case (I think) I do just as well by using a dynamic array and setting the length before I use it.

Charles D Hixson wrote:
> Hasan Aljudy wrote:
> 
>>
>>Charles D Hixson wrote:
>>
>>>Mike Parker wrote:
>>>
>>>
>>>>Charles D Hixson wrote:
>>>>
>>>>
>>>>>...
>>
>>Note that float vals[][] in D is actually a jagged array.
>>I think it would be a better idea to store the matrix internally as a
>>one-dimensional array.
>>
> 
> I'm sure you're right.  I'd planned to allocate a static
> array at run time, but apparently that only works for one
> dimensional arrays...in which case (I think) I do just as
> well by using a dynamic array and setting the length before
> I use it.
> 

I'm not sure I understand the limitation, but if you mean what I think you do, might a template solve the situation?

-- Chris Nicholson-Sauls

Charles D Hixson wrote:
> Hasan Aljudy wrote:
> 
>>
>>Charles D Hixson wrote:
>>
>>>Mike Parker wrote:
>>>
>>>
>>>>Charles D Hixson wrote:
>>>>
>>>>
>>>>>...
>>
>>Note that float vals[][] in D is actually a jagged array.
>>I think it would be a better idea to store the matrix internally as a
>>one-dimensional array.
>>
> 
> I'm sure you're right.  I'd planned to allocate a static
> array at run time, but apparently that only works for one
> dimensional arrays...in which case (I think) I do just as
> well by using a dynamic array and setting the length before
> I use it.
> 

uhh .. static array means array allocated at compile time ^_^'

Hasan Aljudy wrote:
> 
> 
> Charles D Hixson wrote:
>> Hasan Aljudy wrote:
>>
>>>
>>> Charles D Hixson wrote:
>>>
>>>> Mike Parker wrote:
>>>>
>>>>
>>>>> Charles D Hixson wrote:
>>>>>
>>>>>
>>>>>> ...
>>>
>>> Note that float vals[][] in D is actually a jagged array.
>>> I think it would be a better idea to store the matrix internally as a
>>> one-dimensional array.
>>>
>>
>> I'm sure you're right.  I'd planned to allocate a static array at run time, but apparently that only works for one dimensional arrays...in which case (I think) I do just as well by using a dynamic array and setting the length before I use it.
>>
> 
> uhh .. static array means array allocated at compile time ^_^'
Which is probably where I went wrong.  I was thinking of
"fixed size" as opposed to "dynamic", so I was figuring that
I could allocate a "static" (i.e. fixed size) doubly indexed
array on the stack.  It's no big deal...it just means that I
need to code in an index method (ndx = row + col*(# rows) ).

Charles D Hixson wrote:
<snip>
> Although... well, I was asking about something that would
> look more like:
> 
> class MyMatrix
> {
>    float at(uint i, uint j)
>    {
>       return values[i][j];
>    }
> 
>    float at(float val, uint i, uint j)
>    {
>       values[i][j] = val;
>       return val;  //  Not sure about this line

What is there to be not sure about about it?  Whether you can shorten the two statements to

    return values[i][j] = val;

?  Well, of course you can.

>    }
> }
> 
> MyMatrix mat = new mat;
> mat.at(0,0) = 0.0f;
> float f = mat.at(0,0);
> 
> where the property is "at".  Knowing this would still be
> useful, as I might some time want to access things via more
> than one method (imagine I had sorted indexes, and was
> retrieving the same thing sometimes by name and sometimes by
> date, and occasionally by record number).
> Still, if this works for opIndexAssign, it probably works
> for all properties.

You could define a property that returns a wrapper object, and then use opIndex(assign) on that.  For example:

    class MyMatrix {
       struct At {    // I don't think there are "inner" structs as such
            MyMatrix m;

            float opIndex(uint i, uint j) {
                return m.values[i][j];
            }

            float opIndexAssign(float val, uint i, uint j) {
                return m.values[i][j] = val;
            }
        }

        At at() {
            return * cast(At*) cast(void*) &this;
        }
    }

    MyMatrix mat = new mat;
    mat.at[0,0] = 0.0f;
    float f = mat.at[0,0];

Except that values is undeclared....

Stewart.

-- 
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GCS/M d- s:-@ C++@ a->--- UB@ P+ L E@ W++@ N+++ o K-@ w++@ O? M V? PS- PE- Y? PGP- t- 5? X? R b DI? D G e++++ h-- r-- !y
------END GEEK CODE BLOCK------

My e-mail is valid but not my primary mailbox.  Please keep replies on the 'group where everyone may benefit.