Re: Assign to Array Column
On Wednesday, 1 February 2023 at 03:45:11 UTC, Salih Dincer wrote: On Tuesday, 31 January 2023 at 01:04:41 UTC, Paul wrote: Can I perform a similar assignment to the column? This, myArr[][0] = 5, doesn't work. Of course, this question has a short answer and a long answer. So the issue is more about column-major. I am someone who likes to talk with codes. In fact, everything is side by side in memory. This example (something like array) covers the issue: Thanks Salih. Much appreciated.
Re: Address of a class object
On Thursday, 5 January 2023 at 05:59:26 UTC, Ali Çehreli wrote: On 1/4/23 20:04, Paul wrote: >> (Again, there is no problem here; we are just learning.) >> Ali > > Do I have this much right? > ..with this output? Looks good to me. While we're here, you can force the class objects to be on the stack as well: scope MyClassVar1 = new MyClass(); I replaced 'auto' with 'scope'. Ali I was tinkering with this use of 'scope' and the math for pointer location, object size, and alignment started working out.
Re: Assign to Array Column
Sorry, I forget this:
```d
enum : size_t {
ROW = 3,
COL = 3,
SUM = ROW * COL
}
```
SDB@79
Re: Assign to Array Column
On Tuesday, 31 January 2023 at 01:04:41 UTC, Paul wrote:
Can I perform a similar assignment to the column? This,
myArr[][0] = 5, doesn't work.
Of course, this question has a short answer and a long answer. So
the issue is more about column-major. I am someone who likes to
talk with codes. In fact, everything is side by side in memory.
This example (something like array) covers the issue:
```d
import std.stdio;
void main()
{
int[COL][ROW] sample = [ [ 5, 5, 5 ],
[ 0, 0, 0 ],
[ 0, 0, 0 ],
];
auto arrayish = Arrayish!int(ROW, COL);
assert(arrayish.length == SUM);
// copy array...
foreach(r; 0..ROW)
{
foreach(c; 0..COL)
{
arrayish[r, c] = sample[r][c];
}
}
arrayish.print();
foreach(n; 0..COL)
{
//arrayish.columnMajor(n).writeln;/*
arrayish[n].writeln;//*/
}
// clear and set...
arrayish.elements[] = 0;
foreach(r; 0..ROW) arrayish[r] = 5;
arrayish.print();
}
struct Arrayish(T) {
private {
T[] elements;
const size_t row, col;
}
this(size_t row, size_t col) {
this.elements = new T[row * col];
this.row = row;
this.col = col;
}
ref T opIndex(size_t row = 0, size_t col = 0) {
return elements[row * this.col + col];
}
ref T columnMajor(size_t row = 0, size_t col = 0) {
return elements[col * this.row + row];
}
auto length() {
return row * col;
}
void print() {
foreach(r; 0..row) {
foreach(c; 0..col)
this[r, c].write;
writeln;
}
}
} /* Prints:
555
000
000
5
0
0
500
500
500
*/
```
SDB@79
Re: More Elegant Settable Methods?
On Monday, 30 January 2023 at 07:48:09 UTC, Salih Dincer wrote:
On Saturday, 21 January 2023 at 23:07:45 UTC, jwatson-CO-edu
wrote:
I am trying to create a struct with a settable method that has
access to the struct scope.
Is this the only way?
Is there a way to give access without explicitly passing
`this`?
Why not use the delegate? What exactly do you want to do? Set
after constructor or assign delegate?
```d
struct S {
float /*--*/ a;
float /*--*/ b;
void delegate(float x, float y) set;
auto sum() { return a + b; }
}
void main() {
S s;
s.set = (x, y) {
s.a = x;
s.b = y;
};
s.set(10, 20);
assert(s.sum == 30);
}
```
SDB@79
So `delegate` looks closer to what I want. I am looking to
implement a [Strategy
Pattern](https://en.wikipedia.org/wiki/Strategy_pattern) in which
I have an object with an update method which is settable at
runtime, either during instantiation or after. The function you
have assigned to `set` has access to the `S` object, just like I
had wished; Thank you!
The application is a [Braitenberg
Vehicle](https://en.wikipedia.org/wiki/Braitenberg_vehicle)
environment. There are a more than a few component types that
are connected to each other in the same way and pass messages of
a consistent type. I'd like not to write a struct/class for each
component type; but rather write their common structure once and
set their type-specific behavior as they are created.
It looks like I can write a function for each component type and
assign a `delegate` update strategy after the common struct has
been created. This is what I had asked for. Thank you for this
lesson.
Re: hasUDA alternatives?
On Saturday, 28 January 2023 at 17:16:07 UTC, Hipreme wrote: [...] Thank you. I incorporated some of these ideas and looked up how to profile the compilation with tracy, and now dmd memory requirements are down to ~2100 Mb. It's still a far cry from your 250 Mb, however. I changed it to only call `getSymbolsByUDA` once (per plugin module) and then filtered it by use of arrays of indices, like you suggested. This reduced memory needed by some 150 Mb; less than I had hoped but still a step in the right direction. I then went through the compilation with tracy and removed, replaced or versioned out parts that the compiler seemed to spend a long time on in semantic analysis. I lost some functionality but the returns were considerable. The remaining big offender seems to be `std.concurrency.send`. I consolidated some unique instantiations, but it's pretty core to how the thing works and I'm not sure what I can neatly do about that.
