Add `AsCollection` option to the `-Split` Operator

Summary of the new feature / enhancement

Currently the -Split operator returns a string array (String[]) which immediately unrolls which is not always useful in case you want change the returned strings in a larger stream:

Consider the following list:

$List = 'a,b', 'c,d', 'e,f'

I would like split each item on the comma and add the numbers 1 and 2 in the front of the resulted characters:

1a
2b
1c
2d
1e
2f

Probably the easiest way to do this is reassigning the split item:

• create a loop
• split each item and reassign the results
• make changes to each subitem in the assignment

$List | Foreach-Object {
    $Split = $_ -Split ','
    '1' + $Split[0]
    '2' + $Split[1]
}

…or do things along with the format string operator:

$List | Foreach-Object {
    $Split = $_ -Split ','
    '1{0} 2{1}' -f $Split
}

Proposed technical implementation details (optional)

If -Split would optionally return a [Collections.ObjectModel.Collection[String]], I could have the following syntactic sugar (wishful thinking):

$List -Split ',',0,'AsCollection' | Foreach-Object {
    '1' + $_[0]
    '2' + $_[1]
}

In other words:

$SplitAsCollection = # $List -Split ',',0,'AsCollection'
[Collections.ObjectModel.Collection[String]]('a', 'b'),
[Collections.ObjectModel.Collection[String]]('c', 'd'),
[Collections.ObjectModel.Collection[String]]('e', 'f')

$SplitAsCollection | Foreach-Object { # $List -Split ',',0,'AsCollection' | Foreach-Object { 
    '1' + $_[0]
    '2' + $_[1]
}

…or do things along with the format string operator:

# $List -Split ',',2,'AsCollection' | Foreach-Object { '1{0} 2{1}' -f @($_) }
$SplitAsCollection | Foreach-Object { '1{0} 2{1}' -f @($_) }

(where the -f operator should actually recognize a [psobject] collection: '1{0} 2{1}' -f $_, see: #14355)

[237dmitry]

Add AsCollection option to the -Split Operator.

This is a completely different matter. I fully support you.

[237dmitry]

I would be careful with such requests. A million scripts have been written where the -split operator returns an array of strings. What could be the consequences can not be foreseen.

Besides, the current syntax (as in the example in the summary) is still supposed to work on iterated scalars

This is the solution for your specific case.