• "Saaa" <empty needmail.com> Jun 08 2009
• Christopher Wright <dhasenan gmail.com> Jun 08 2009
• "Saaa" <empty needmail.com> Jun 08 2009
• "Saaa" <empty needmail.com> Jun 08 2009
• "Saaa" <empty needmail.com> Jun 08 2009

"Saaa" <empty needmail.com> writes:

I just finished my array parser but I can't support just any depth because 
each depth needs its own code the way I am doing it now :(
Also, as you can see, I am using a doubling strategy to minimize the amount 
of allocations (strating with 4). Is this still a good strategy with D 
having a GC?

..
switch( depth )
{

case 0:
if( temp.length < index[depth] ) temp.length = temp.length * 2;
break;

static if( is(U A:A[]))
{
case 1:
if( temp[ index[0] ].length < index[depth] ) temp[index[0]].length = 
temp[index[0]].length * 2;
break;
}

static if( is(U A:A[][]))
{
case 2:
if( temp[ index[0] ][ index[1] ].length < index[depth] ) temp[ index[0] ][ 
index[1] ].length = temp[ index[0] ][ index[1] ].length * 2;
break;
}

default:
assert(false);
break;
}
.. 

Christopher Wright <dhasenan gmail.com> writes:

Saaa wrote:
 I just finished my array parser but I can't support just any depth because 
 each depth needs its own code the way I am doing it now :(


Recursion?
static if (is (U A : A[])) will give you int[] for int[][], so you can 
recursively call the parsing function with A as the type argument rather 
than U.

"Saaa" <empty needmail.com> writes:

"Christopher Wright" <dhasenan gmail.com> wrote in message 
news:h0kagg$13so$1 digitalmars.com...
 Saaa wrote:
 I just finished my array parser but I can't support just any depth 
 because each depth needs its own code the way I am doing it now :(


 Recursion?
 static if (is (U A : A[])) will give you int[] for int[][], so you can 
 recursively call the parsing function with A as the type argument rather 
 than U.


I'm sorry, it is still a bit difficult to see as it's all a bit new to me 
but,
depth is the current depth not the depth of the array.
With a[][][] you  can be in 3 depth levels so there need to be as
many cases as the depth of the array.
I probably also need recursion to in stead of the switch create a function
which can set the length of an array at a certain depth :)

"Saaa" <empty needmail.com> writes:

"Christopher Wright" <dhasenan gmail.com> wrote in message 
news:h0kagg$13so$1 digitalmars.com...
 Saaa wrote:
 I just finished my array parser but I can't support just any depth 
 because each depth needs its own code the way I am doing it now :(


 Recursion?
 static if (is (U A : A[])) will give you int[] for int[][], so you can 
 recursively call the parsing function with A as the type argument rather 
 than U.


My attempt to rewrite the switch (failed : )

ddata\ddata.d(94): Error: slice expression array[] is not a modifiable 
lvalue
ddata\ddata.d(169): template instance ddata.ddata.setLength!(int[]) error 
instantiating

//an array depth walker  :)
void setLength (T)( ref T array, int depth , int index)
{
 if(depth > 0)
 {
  depth--;
  setLength (array[], depth, index); //94
 }
 else
 {
  if(array.length < index) array.length = array.length * 2;
 }
} 

"Saaa" <empty needmail.com> writes:

meant this:
which of course also fails,
but I hope you get the jist

void setLength (T)( ref T array, int depth , int index[])
{
  if(depth > 0)
  {
    depth--;
    setLength (&array[index[0]], depth, index[1..$]);
  }
  else
  {
    if(array.length < index[0]) array.length = array.length * 2;
  }
}