Purity in D – new article

[bearophile]

David Nadlinger:

> http://www.reddit.com/r/programming/comments/u84fc/purity_in_d/

On Reddit "yogthos" has said:
http://www.reddit.com/r/programming/comments/u84fc/purity_in_d/c4t8czg

>they're called persistent data structures, and wikipedia has a 
>nice article showing how they work. These are implemented in 
>languages like Haskell and Clojure, and offer performance that's 
>within that of using mutable data.<

Those data structures are interesting, they are persistent so 
they remove certain classes of bugs and allow for certain 
high-level algorithms, they play well with multiple CPUs cores, 
so probably they will be handy in D too. But on a single CPU 
their performance is not so good compared to mutable flat 
array-based data structures. Idiomatic Clojure code is often 
slow, and it uses tons of RAM, several times the memory used by 
equivalent Python code. So the situation isn't as good as they 
keep saying.

Bye,
bearophile