PowerLINQ

Imms overrides LINQ operations, such as Select and Where with optimized implementations that return a collection of the same type as the input. This also means that they don’t execute lazily. “ Look at the following code as an example:

ImmList<string> names = ImmList.Of("greg", "maya", "steve", "franklin");
ImmList<string> startWithG = 
	from name in names
	where name.StartsWith("g")
	select name;
 
ImmList<string> peopleInBothLists =
	from name in names
	join name2 in startWithG on name equals name2
	orderby name
	select name;

Imms.Abstract §

Imms implements LINQ operations and other functionality through the Imms.Abstract assembly. This assembly contains highly abstract base classes and interfaces that Imms collections inherit from and implement.

This works like the much-vaunted Scala collections API, except that C# doesn’t have Scala’s type system, so this turned out to be quite difficult. I eventually settled on a combination of:

1. Some boilerplate that needs to be implemented for each collection
2. A lot of generic code in base classes
3. Some code genertion templates

The system can be reused by more specialized collections.