Zift is a lightweight, composable query library for .NET that adds dynamic filtering and pagination on top of IQueryable<T>.

It builds on existing IQueryable<T> queries using familiar LINQ operators such as Where(...) and OrderBy(...).

The library focuses on two core capabilities:

• Dynamic querying: string-based filtering via Where(...)
• Pagination: offset-based and cursor-based pagination

Dynamic Querying

Zift allows dynamic filtering using a compact, expressive string syntax that is parsed and translated into LINQ expression trees.

var categories = context.Categories
    .Where("Products:any(Reviews:any(Rating >= 4))")
    .ToList();

Supported Syntax

• Property navigation Name, Author.Email

• Logical operators &&, ||, !

  Example: Price > 100 && Price < 500

• Grouping (...) for evaluation order

  Example: (Price > 100 && Price < 500) || IsFeatured == true

• Comparison operators ==, !=, <, <=, >, >=

  Example: Rating >= 4

• String operators %= (contains), ^= (starts with), $= (ends with)

  Example: Title %= "C#"

• in operator with list literals

  Example: Status in ["Active", "Pending"]

• Quantifiers on collections

  • :any(predicate)
  • :all(predicate)
  • :any() (existence check)

  Example: Reviews:any(Author.Email $= "@example.com")

• Collection projections

  • :count

  Example: Products:count >= 2

Pagination

Zift supports two pagination strategies that operate directly on IQueryable<T> and can be combined with dynamic querying:

• Offset-based pagination
• Cursor-based pagination

Offset Pagination

Offset pagination is 1-based and uses Skip / Take under the hood. It is best suited for small to medium result sets where total counts are required.

var page = await context.Categories
    .OrderBy(c => c.Name)
    .ToPageAsync(pageNumber: 1, pageSize: 25);

Result shape

page.Items
page.PageNumber
page.PageSize
page.PageCount
page.HasNextPage
page.HasPreviousPage
page.TotalItemCount

Cursor Pagination

Cursor pagination (keyset pagination) is designed for stable and efficient traversal over ordered data, particularly for large or unbounded result sets.

It is enabled by calling AsCursorQuery() on the IQueryable<T>.

var page = context.Products
    .AsCursorQuery()
    .OrderBy("Name ASC, Price DESC")
    .ToCursorPage(pageSize: 25);

Note: Ordering for cursor pagination must be applied after calling AsCursorQuery(). Any ordering applied before AsCursorQuery() is ignored.

Cursor pagination requires at least one ordering clause to be provided; otherwise execution fails.

To continue navigation from a previously retrieved page, use the cursor values exposed by that page as anchors for further traversal.

// Forward traversal
if (page.HasNextPage)
{
    var nextPage = query
        .After(page.EndCursor)
        .ToCursorPage(pageSize: 25);
}

// Backward traversal
if (page.HasPreviousPage)
{
    var previousPage = query
        .Before(page.StartCursor)
        .ToCursorPage(pageSize: 25);
}

Result shape

page.Items
page.StartCursor
page.EndCursor
page.HasNextPage
page.HasPreviousPage