Question

I have an IEnumerable of type String with Default values and a fix order.
I have a List of type Module with values in a random order.
I want to have ONE list of unique objects of type Module.
What I get with the below code is:
ONE list of unique objects of type String.

Someone knows a trick around this?

static void Main(string[] args) {    

    List<Module> moduleList = new List<Module>() {
        new Module{ ModuleId = 1, ModuleType = "world"},
        new Module{ ModuleId = 2, ModuleType = "wayne"},
        new Module{ ModuleId = 3, ModuleType = "hallo"},
        new Module{ ModuleId = 4, ModuleType = "tes"},
        new Module{ ModuleId = 5, ModuleType = "mi"},
        new Module{ ModuleId = 6, ModuleType = "haha"},
        new Module{ ModuleId = 7, ModuleType = "pipi"},
        new Module{ ModuleId = 8, ModuleType = "bla"},  
    };

    // This result is fine that the list is unified and the predefined 
    // values order is not changed: bla, tes, mi 
    // BUT I need to return a query with Module objects

    var query = GetDefaultValues().Union(moduleList.Select(t => t.ModuleType));
}

private static IEnumerable<string> GetDefaultValues() {
    yield return "bla";
    yield return "tes";
    yield return "mi";
}

Do a new Module() in every lambda and copy the values is NO option for me.

UPDATE:

Desired output:

a list of Modules:

new Module{ ModuleId = 8, ModuleType = "bla"},
new Module{ ModuleId = 4, ModuleType = "tes"},
new Module{ ModuleId = 5, ModuleType = "mi"},

new Module{ ModuleId = 1, ModuleType = "world"},
new Module{ ModuleId = 2, ModuleType = "wayne"},
new Module{ ModuleId = 3, ModuleType = "hallo"},
new Module{ ModuleId = 6, ModuleType = "haha"},
new Module{ ModuleId = 7, ModuleType = "pipi"},

Answer 1

var query = GetDefaultValues()
            .Select(v => moduleList.Find(m => m.ModuleType == v))
            .Union(moduleList);