Re: Classes and templates
On Monday, 31 October 2016 at 22:33:11 UTC, John Colvin wrote: On Monday, 31 October 2016 at 19:24:46 UTC, Hefferman wrote: Hello, I've been trying to implement a class for sorting which accepts arrays which "different" data types. Hard to describe, here's my example (filename sorting.d): [...] Glad to see you're getting helpful responses here, but just an FYI: https://forum.dlang.org/group/learn would be a more appropriate forum for questions like this. Thanks to all for replying! @J.C.: I'll keep it in mind for the next time.
Re: Classes and templates
On Monday, 31 October 2016 at 19:24:46 UTC, Hefferman wrote: Hello, I've been trying to implement a class for sorting which accepts arrays which "different" data types. Hard to describe, here's my example (filename sorting.d): [...] Glad to see you're getting helpful responses here, but just an FYI: https://forum.dlang.org/group/learn would be a more appropriate forum for questions like this.
Re: Classes and templates
On Monday, 31 October 2016 at 20:25:18 UTC, Hefferman wrote:
for (uint k = 1; k < n; k++) {
if (a[k-1] > a[k]) {
T tmp = a[k];
a[k] = a[k+1];
a[k+1] = tmp;
sorted = false;
}
}
n--;
} while (!sorted);
}
}
[/code]
It gives a Range Violation upon executing, but I guess it's
part of the algorithm
The value of n is array length, so k reaches (n - 1), therefore
k+1 gives you n which is out of bounds.
Re: Classes and templates
On Monday, 31 October 2016 at 20:20:09 UTC, Meta wrote:
[...]
You can't use an un-instantiated template as a type anyway,
unlike Java. There the above is illegal because of `BubbleSort
b = ...`. The symbol BubbleSort by itself is not a type; you
have to instantiate it with template arguments to create a
type. So you *could* do it like this:
BubbleSort!(typeof(arr)) b = new BubbleSort!(typeof(arr));
But that's too verbose. There's need need to repeat ourselves.
You can instead use `auto` and omit the type of `b`, which will
be inferred from the right hand side:
auto b = new BubbleSort!(typeof(arr));
Thanks! This compiled just fine...
[code]
import std.random;
import std.stdio;
void main()
{
immutable uint N = 10_000;
double[] arr = new double[](N);
for (uint k = 0; k < N; k++) arr[k] = uniform(0, N);
auto b = new BubbleSort!(typeof(arr));
b.Sort(arr);
}
public class BubbleSort(T)
{
private T[] a;
private uint n;
public void Sort(T)(T[] a) {
n = a.length;
bubblesort();
}
private void bubblesort() {
bool sorted;
do {
sorted = true;
for (uint k = 1; k < n; k++) {
if (a[k-1] > a[k]) {
T tmp = a[k];
a[k] = a[k+1];
a[k+1] = tmp;
sorted = false;
}
}
n--;
} while (!sorted);
}
}
[/code]
It gives a Range Violation upon executing, but I guess it's part
of the algorithm
Re: Classes and templates
On Monday, 31 October 2016 at 20:06:22 UTC, Hefferman wrote: On Monday, 31 October 2016 at 19:43:57 UTC, Adam D. Ruppe wrote: On Monday, 31 October 2016 at 19:24:46 UTC, Hefferman wrote: Give a template type when crating it new BubbleSort!(string) for example Is it possible to create this using "typeof"? E. g. "BubbleSort b = new BubbleSort!(typeof(arr));" Compilation fails with that line You can't use an un-instantiated template as a type anyway, unlike Java. There the above is illegal because of `BubbleSort b = ...`. The symbol BubbleSort by itself is not a type; you have to instantiate it with template arguments to create a type. So you *could* do it like this: BubbleSort!(typeof(arr)) b = new BubbleSort!(typeof(arr)); But that's too verbose. There's need need to repeat ourselves. You can instead use `auto` and omit the type of `b`, which will be inferred from the right hand side: auto b = new BubbleSort!(typeof(arr));
Re: Classes and templates
On Monday, 31 October 2016 at 19:43:57 UTC, Adam D. Ruppe wrote: On Monday, 31 October 2016 at 19:24:46 UTC, Hefferman wrote: Give a template type when crating it new BubbleSort!(string) for example Is it possible to create this using "typeof"? E. g. "BubbleSort b = new BubbleSort!(typeof(arr));" Compilation fails with that line
Re: Classes and templates
On Monday, 31 October 2016 at 19:24:46 UTC, Hefferman wrote: Whenever I try to compile this, it throws an error "class sorting.BubbleSort(T) is used as a type". How do I get a workaround? Give a template type when crating it new BubbleSort!(string) for example
