Rich Hickey's slides from jvm lang summit - worth a read?

[Walter Bright]

bearophile wrote:
> Walter Bright:
> 
>> I've been thinking of transitioning dmd's semantic analysis to
>> using immutable data structures because it will reduce allocations,
>> not increase them.<
> 
> As usual I am ignorant about such matters, so I can't give you a good
> answer. But from what I've seen in immutable-based languages, they
> produce a sustained flux of small/little immutable objects that the
> GC has to free and allocate all the time. This stresses the GC.
> Surely people here that know Clojure or Scala, Haskell or F# may give
> you a better answer. Maybe even numbers of the amount of object flux
> they face in normal programs. So the situation with strings may be
> not generalizable to the other immutable data structures a program
> may need to use.

Some languages generate lots of allocations for other reasons, such as 
lack of value aggregates that can be put on the stack.