• Samuel Redding (15/15) Jan 19 Hello there,
• Sergey (11/14) Jan 19 ```d
• Paul Backus (21/36) Jan 19 The exact D equivalent of your Python code would be to use
• user1234 (8/23) Jan 19 iota is a lazy range. As shown in the other answer you can yield
• Samuel Redding (2/21) Jan 19 Thanks a lot to all of you!
• torhu (6/13) Jan 26 For the record, you can extend a list using a range object in

Samuel Redding <samred mail.com> writes:

Hello there,

is it possible to concat an array and a range? In Python one 
would have
"""
list1 = [1, 2, 3]
list1 += array.array('L', range(a, b))
"""

The equivalent in D should be something like
"""
ulong[] list1 = [1, 2, 3];
list1 ~= iota(a, b);
"""

I haven't found a way to do this. The only way to do it seems to 
extend "list1" and then iterate over the range and insert the 
elements.

Sergey <kornburn yandex.ru> writes:

On Sunday, 19 January 2025 at 18:57:51 UTC, Samuel Redding wrote:
 I haven't found a way to do this. The only way to do it seems 
 to extend "list1" and then iterate over the range and insert 
 the elements.

```d
import std;

void main() {
     ulong[] list1 = [1, 2, 3];
     ulong a = 7;
     ulong b = 10;
	list1 ~= iota(a,b).array;
     writeln(list1); // [1, 2, 3, 7, 8, 9]
}
```

Paul Backus <snarwin gmail.com> writes:

On Sunday, 19 January 2025 at 18:57:51 UTC, Samuel Redding wrote:
 Hello there,

 is it possible to concat an array and a range? In Python one 
 would have
 """
 list1 = [1, 2, 3]
 list1 += array.array('L', range(a, b))
 """

 The equivalent in D should be something like
 """
 ulong[] list1 = [1, 2, 3];
 list1 ~= iota(a, b);
 """

 I haven't found a way to do this. The only way to do it seems 
 to extend "list1" and then iterate over the range and insert 
 the elements.

The exact D equivalent of your Python code would be to use 
`std.array.array` to create an array with the range's elements. 
For example:

     import std.range : iota;
     import std.array : array;

     ulong[] list1 = [1, 2, 3];
     list1 ~= iota(4UL, 10UL).array;

There is also another way to do this which avoids allocating (and 
immediately discarding) a temporary array:

     import std.range : iota;
     import std.array : appender;
     import std.algorithm : copy;

     ulong[] list1 = [1, 2, 3];
     copy(iota(4UL, 10UL), appender(&list1));

In this code:

* `appender(&list1)` creates an output range which appends each 
element inserted into it to `list1`
* `copy` takes each element from an input range (in this case, 
`iota(4UL, 10UL)`) and inserts it into an output range (in this 
case, `appender(&list1)`).

user1234 <user1234 12.de> writes:

On Sunday, 19 January 2025 at 18:57:51 UTC, Samuel Redding wrote:
 Hello there,

 is it possible to concat an array and a range? In Python one 
 would have
 """
 list1 = [1, 2, 3]
 list1 += array.array('L', range(a, b))
 """

 The equivalent in D should be something like
 """
 ulong[] list1 = [1, 2, 3];
 list1 ~= iota(a, b);
 """

 I haven't found a way to do this. The only way to do it seems 
 to extend "list1" and then iterate over the range and insert 
 the elements.

iota is a lazy range. As shown in the other answer you can yield 
the lazy thing using `.array`. But assuming it's ok to create a 
distinctive iterator you can also chain the two things:

```d
auto list2 = std.range.chain(list1,iota(a,b));
```

with list2 being fully lazy.

Samuel Redding <samred mail.com> writes:

On Sunday, 19 January 2025 at 19:35:31 UTC, user1234 wrote:
 On Sunday, 19 January 2025 at 18:57:51 UTC, Samuel Redding 
 wrote:
 Hello there,

 is it possible to concat an array and a range? In Python one 
 would have
 """
 list1 = [1, 2, 3]
 list1 += array.array('L', range(a, b))
 """

 The equivalent in D should be something like
 """
 ulong[] list1 = [1, 2, 3];
 list1 ~= iota(a, b);
 """

 I haven't found a way to do this. The only way to do it seems 
 [...]


Thanks a lot to all of you!

torhu <torhu yahoo.com> writes:

On Sunday, 19 January 2025 at 18:57:51 UTC, Samuel Redding wrote:
 Hello there,

 is it possible to concat an array and a range? In Python one 
 would have
 """
 list1 = [1, 2, 3]
 list1 += array.array('L', range(a, b))
 """

For the record, you can extend a list using a range object in 
Python:

     list1.extend(range(a, b))

or if you just want to iterate over them in order:

     iter = itertools.chain(list1, range(a, b))