[Haskell-cafe] Re: Red-Blue Stack

[Stephan Friedrichs]

apfelmus wrote:
> [..]
> 
> Persistent data structures are harder to come up with than ephemeral
> ones, [...]

Yes, in some cases it's quite hard to find a persistent solution for a
data structure that is rather trivial compared to its ephemeral
counterpart. My question is: Is there a case, where finding a persistent
solution that performs equally well is *impossible* rather than just
harder? I mean might there be a case where (forced) persistence (as we
have in pure Haskell) is a definite disadvantage in terms of big-O
notation? Do some problems even move from P to NP in a persistent setting?

Stephan

-- 

Früher hieß es ja: Ich denke, also bin ich.
Heute weiß man: Es geht auch so.

 - Dieter Nuhr