What's the best name for a non-mutating “add” method on an immutable collection?

Question

Sorry for the waffly title - if I could come up with a concise title, I wouldn\'t have to ask the question.

Suppose I have an immutable list type. It has an operat

Answer 1

I like mmyers suggestion of CopyAndAdd. In keeping with a "mutation" theme, maybe you could go with Bud (asexual reproduction), Grow, Replicate, or Evolve? =)

EDIT: To continue with my genetic theme, how about Procreate, implying that a new object is made which is based on the previous one, but with something new added.

Answer 2

A few random thoughts:

• ImmutableAdd()
• Append()
• ImmutableList<T>(ImmutableList<T> originalList, T newItem) Constructor

Answer 3

In situations like that, I usually go with Concat. That usually implies to me that a new object is being created.

var p = listA.Concat(listB);
var k = listA.Concat(item);

Answer 4

Join seems appropriate.

Answer 5

Apparently I'm the first Obj-C/Cocoa person to answer this question.

NNString *empty = [[NSString alloc] init];
NSString *list1 = [empty stringByAppendingString:@"Hello"];
NSString *list2 = [list1 stringByAppendingString:@"immutable"];
NSString *list3 = [list2 stringByAppendingString:@"word"];

Not going to win any code golf games with this.

Answer 6

I think that Plus() and Minus() or, alternatively, Including(), Excluding() are reasonable at implying immutable behavior.

However, no naming choice will ever make it perfectly clear to everyone, so I personally believe that a good xml doc comment would go a very long way here. VS throws these right in your face when you write code in the IDE - they're hard to ignore.