regex Match a capture group's items only once - regex

Question

So I'm trying to split a string in several options, but those options are allowed to occur only once. I've figured out how to make it match all options, but when an option occurs twice or more it matches every single option.
Example string: --split1 testsplit 1 --split2 test split 2 --split3 t e s t split 3 --split1 split1 again
Regex: /-{1,2}(split1|split2|split3) [\w|\s]+/g
Right now it is matching all cases and I want it to match --split1, --split2 and --split3 only once (so --split1 split1 again will not be matched).
I'm probably missing something really straight forward, but anyone care to help out? :)
Edit:
Decided to handle the extra occurances showing up in a script and not through RegEx, easier error handling. Thanks for the help!

Answer 1

EDIT: Somehow I ended up here from the PHP section, hence the PHP code. The same principles apply to any other language, however.
I realise that OP has said they have found a solution, but I am putting this here for future visitors.
function splitter(string $str, int $splits, $split = "--split")
{
$a = array();
for ($i = $splits; $i > 0; $i--) {
if (strpos($str, "$split{$i} ") !== false) {
$a[] = substr($str, strpos($str, "$split{$i} ") + strlen("$split{$i} "));
$str = substr($str, 0, strpos($str, "$split{$i} "));
}
}
return array_reverse($a);
}
This function will take the string to be split, as well as how many segments there will be. Use it like so:
$array = splitter($str, 3);
It will successfully explode the array around the $split parameter.
The parameters are used as follows:
$str
The string that you want to split. In your instance it is: --split1 testsplit 1 --split2 test split 2 --split3 t e s t split 3 --split1 split1 again.
$splits
This is how many elements of the array you wish to create. In your instance, there are 3 distinct splits.
If a split is not found, then it will be skipped. For instance, if you were to have --split1 and --split3 but no --split2 then the array will only be split twice.
$split
This is the string that will be the delimiter of the array. Note that it must be as specified in the question. This means that if you want to split using --myNewSplit then it will append that string with a number from 1 to $splits.
All elements end with a space since the function looks for $split and you have a space before each split. If you don't want to have the trailing whitespace then you can change the code to this:
$a[] = trim(substr($str, strpos($str, "$split{$i} ") + strlen("$split{$i} ")));
Also, notice that strpos looks for a space after the delimiter. Again, if you don't want the space then remove it from the string.
The reason I have used a function is that it will make it flexible for you in the future if you decide that you want to have four splits or change the delimiter.
Obviously, if you no longer want a numerically changing delimiter then the explode function exists for this purpose.

Answer 2

-{1,2}((split1)|(split2)|(split3)) [\w|\s]+
Something like this? This will, in this case, create 3 arrays which all will have an array of elements of the same name in them. Hope this helps