• Python (17/17) May 02 I am trying to get some items from a list, but `find` gives me
• Richard (Rikki) Andrew Cattermole (2/2) May 02 Have you tried filter?
• Python (4/6) May 02 Thx. Anyway, what find returns aftrr first occurrence is
• =?UTF-8?Q?Ali_=C3=87ehreli?= (6/12) May 03 Yes, understandably unexpected.
• Jonathan M Davis (14/26) May 03 It's also far more useful in the general case, since you can always just...
• monkyyy (4/21) May 02 https://hoogletranslate.com

Python <python python.com> writes:

I am trying to get some items from a list, but `find` gives me 
unexpected results.

```
import std.stdio;
import std.algorithm;

int[] x = [1, 2, 3, 4, 5, 1, 2, 3];

void main()
{
     auto selection = x.find!(a => a == 2);

     foreach(item;selection)
     {
         writeln(item);
     }
}
```

Output is 2, 3, 4, 5, 1, 2, 3

"Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:

Have you tried filter?

https://dlang.org/phobos/std_algorithm_iteration.html#.filter

Python <python python.com> writes:

On Friday, 2 May 2025 at 14:33:57 UTC, Richard (Rikki) Andrew 
Cattermole wrote:
 Have you tried filter?

 https://dlang.org/phobos/std_algorithm_iteration.html#.filter

Thx. Anyway, what find returns aftrr first occurrence is 
unexpected.

=?UTF-8?Q?Ali_=C3=87ehreli?= <acehreli yahoo.com> writes:

On 5/2/25 2:44 PM, Python wrote:
 On Friday, 2 May 2025 at 14:33:57 UTC, Richard (Rikki) Andrew Cattermole
 wrote:
 Have you tried filter?

 https://dlang.org/phobos/std_algorithm_iteration.html#.filter

 Thx. Anyway, what find returns aftrr first occurrence is unexpected.

Yes, understandably unexpected.

However, the choice of returning a range solves the other design problem 
of what to do when no item is found. 'find' communicates that case with 
an empty range.

Ali

Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:

On Saturday, May 3, 2025 12:08:45 PM Mountain Daylight Time Ali Çehreli via
Digitalmars-d-learn wrote:
 On 5/2/25 2:44 PM, Python wrote:
  > On Friday, 2 May 2025 at 14:33:57 UTC, Richard (Rikki) Andrew Cattermole
  > wrote:
  >> Have you tried filter?
  >>
  >> https://dlang.org/phobos/std_algorithm_iteration.html#.filter
  >
  > Thx. Anyway, what find returns aftrr first occurrence is unexpected.

 Yes, understandably unexpected.

 However, the choice of returning a range solves the other design problem
 of what to do when no item is found. 'find' communicates that case with
 an empty range.

It's also far more useful in the general case, since you can always just use
front to get the specific element.

And really, when you consider how find with iterators typically works - i.e.
it returns an iterator to the element - having Phobos' find return the range
starting with that element is the equivalent behavior for ranges, since
ranges don't refer to individual elements. In both cases, find iterates
until it finds the element, and then it returns what it was iterating over
at that point in the iteration. It's just that with an iterator, you get
something that points to that individual element, whereas with a range, you
get a range of values which starts with that element. But it's certainly
true that the range equivalents of iterator-based algorithms can take some
getting used to.

- Jonathan M Davis

monkyyy <crazymonkyyy gmail.com> writes:

On Friday, 2 May 2025 at 14:32:04 UTC, Python wrote:
 I am trying to get some items from a list, but `find` gives me 
 unexpected results.

 ```
 import std.stdio;
 import std.algorithm;

 int[] x = [1, 2, 3, 4, 5, 1, 2, 3];

 void main()
 {
     auto selection = x.find!(a => a == 2);

     foreach(item;selection)
     {
         writeln(item);
     }
 }
 ```

 Output is 2, 3, 4, 5, 1, 2, 3



https://hoogletranslate.com

I confirm, its filter

Find, drops until it finds the filter or element