Importing operators

From the readme:

Note: you need to import these operators from kotlinx.collections.immutable package in order for them to take the precedence over the ones from the standard library.

That makes it very easy to accidentally use the standard operators, which obviously has bad performance implications. Perhaps the operator functions should be instance methods so that the compiler prefers them over the standard plus/minus extension functions?

[cbruegg]

Option 3 sounds fair to me, especially since 1 and 2 really don’t seem like feasible solutions. Would all of the current extensions to Iterable/List/Set/Map be made available separately and optimized for the corresponding immutable types? Most of my method calls where collections are passed are calls to those, so if they existed, there wouldn’t be too many places where I’d need to add asList() in my application code.

[ilya-g]

Yes, that is a valid concern.

Unfortunately making them member would clutter the interfaces.

I have another option in mind: if the standard operators know something about immutable collections, they can be specialized in runtime to utilize immutability of those collections.