I actually find 1:1 to be helpful when learning a language.

How debug-able is the internals of the rust lambda version?

I will often write the code so I can simply insert a break point for debugging versus pure anonymous and flow-style functions.

C# example:

    #if DEBUG
    const string TestPoint = "xxxx";
    #endif

    var filtered = items.Where(x =>
    {
        #if DEBUG
        if (x.Name == TestPoint)
            x.ToString()
        #endif
        .....
    });

vs

    var filtered = items.Where(x => ....);