C# LINQ zip function equivalent in query expression-CodePudding

I can join elements of two lists with the Zip function; line1 from file1 with line1 with file2, etc.

var res = lines1.Zip(lines2, (x, y) => $"{x} {y}");

Is there a way to do in a query expression?

var res = from e1 in lines1
          where !string.IsNullOrWhiteSpace(e1)
          from e2 in lines2
          where !string.IsNullOrWhiteSpace(e2)
          select $"{e1} {e2}";

This joins each line from list1 with each line from list2, which is not what I need.

CodePudding user response：

Unfortunately the query syntax doesn't support everything that is available through the method syntax (e.g. Zip() method, self-written extension methods or 3rd party libraries like MoreLinq).

Due to this limitation it is not possible to get this functionality into C# by the user. Instead Microsoft as owner of the language had to implement such an functionality like it is described here.

CodePudding user response：

If you squint pretty hard then this is close:

IEnumerable<string> filtered1 =
    from e1 in lines1
    where !string.IsNullOrWhiteSpace(e1)
    select e1;

IEnumerable<string> filtered2 =
    from e2 in lines2
    where !string.IsNullOrWhiteSpace(e2)
    select e2;

IEnumerable<string> res =
    from x in filtered1.Zip(filtered2, (e1, e2) => (e1, e2))
    select $"{x.e1} {x.e2}";