On 02/09/2012 03:47 AM, MattCodr wrote:
I have a doubt about the best way to insert and move (not replace) some
data on an array.
For example,
In some cases if I want to do action above, I do a loop moving the data
until the point that I want and finally I insert the new data there.
In D I did this:
begin code
.
.
.
int[] arr = [0,1,2,3,4,5,6,7,8,9];
arr.insertInPlace(position, newValue);
arr.popBack();
.
.
.
end code
After the insertInPlace my array changed it's length to 11, so I use
arr.popBack(); to keep the array length = 10;
The code above is working well, I just want know if is there a better way?
Thanks,
Matheus.
Most straightforward that I know of is the following:
arr = arr[0 .. position] ~ [ newValue ] ~ arr[position + 1 .. $];
But if you don't actually want to modify the data, you can merely access
the elements in-place by std.range.chain:
import std.stdio;
import std.range;
void main()
{
int[] arr = [0,1,2,3,4,5,6,7,8,9];
immutable position = arr.length / 2;
immutable newValue = 42;
auto r = chain(arr[0 .. position], [ newValue ], arr[position + 1
.. $]);
writeln(r);
}
'r' above is a lazy range that just provides access to the three ranges
given to it. 'arr' does not change in any way.
Ali
