ZipParams

ZipParams is a small .NET 9 library that extends the standard LINQ zip operation to support any number of collections with the same element type.

The project provides synchronous and asynchronous extension methods for IEnumerable<T> and IAsyncEnumerable<T>.

Features

• Accepts additional collections through params
• Supports any number of collections, including zero
• Produces one read-only row for each group of matching elements
• Stops when the shortest input collection ends
• Evaluates collections lazily
• Disposes every created enumerator
• Propagates cancellation to asynchronous enumerators

Project structure

ZipParams.sln
ZipParams/
  EnumerableExtensions.cs
  ZipParams.csproj
ZipParamsTests/
  EnumerableExtensionsTests.cs
  ZipParamsTests.csproj

Synchronous usage

using ZipParams;

IEnumerable<int> first = [1, 2, 3];
IEnumerable<int> second = [10, 20, 30];
IEnumerable<int> third = [100, 200, 300];

var rows = first.Zip(second, third);

foreach (var row in rows)
{
    Console.WriteLine(string.Join(", ", row));
}

The resulting rows are [1, 10, 100], [2, 20, 200], and [3, 30, 300].

Calling Zip without additional collections produces rows containing only the elements from the source collection.

Asynchronous usage

using ZipParams;

IAsyncEnumerable<int> first = GetFirstAsync();
IAsyncEnumerable<int> second = GetSecondAsync();
IAsyncEnumerable<int> third = GetThirdAsync();

await foreach (var row in first.ZipAsync(second, third))
{
    Console.WriteLine(string.Join(", ", row));
}

ZipAsync follows the same shortest-collection rule and supports cancellation through normal asynchronous enumeration.

Running tests

Run the complete test suite from the repository root:

dotnet test ZipParams.sln

The test project uses xUnit and FluentAssertions. It covers empty params input, multiple equal-length collections, different-length collections, synchronous disposal, and asynchronous disposal.