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Immutability - Developer Support

Immutable Object Graph updates

May 7, 2013 May 7, 2013 05/7/13
Andrew Arnott
In my last post, I introduced a T4 template that constructs efficient and quite capable immutable objects based on the simplest mutable type definition. I also mentioned that the published sample is (necessarily, ala T4 style) open source and hosted online. Two outsiders have already submitted pull requests that have been accepted. Some ...

Simple immutable objects

January 8, 2013 Jan 8, 2013 01/8/13
Andrew Arnott
We’re all familiar with immutable collections now. But immutability is only as immutable as it is deep. And an immutable collection of mutable objects may not provide the depth you’re looking for. So how can one create an immutable object? Suppose you would define the mutable version like this: An immutable version might be ...

Immutable collection algorithmic complexity

January 7, 2013 Jan 7, 2013 01/7/13
Andrew Arnott
I received some feedback from my recent BCL blog post on the prerelease of the immutable collections that my algorithm complexity table left a few important entries out. Here is the table again, with more data filled in (particularly around list indexer lookup and enumeration): A noteworthy trait to call out here is that where a List<...

Immutable collections with mutable performance

August 29, 2011 Aug 29, 2011 08/29/11
Andrew Arnott
In my last post, I detailed the differences among read/write, read only, frozen and immutable collection types.  I described how immutable collections come with a hit to the garbage collector due to the garbage they generate during mutations.  I have a very positive update on that topic. My previous implementation for the ...

Read only, frozen, and immutable collections

August 21, 2011 Aug 21, 2011 08/21/11
Andrew Arnott
[Update: a more recent post with new data on attainable performance of immutable collections] The topics of immutability and functional programming has fascinated me lately.  Mostly because of my work on the Visual Studio Common Project System (CPS) which is a large, highly multi-threaded code base that only remains sane because of its...