[Haskell-cafe] implementing python-style dictionary in Haskell

[Ryan Ingram]

On Tue, Nov 18, 2008 at 12:46 PM, Luke Palmer <lrpalmer at gmail.com> wrote:
> But when these persistent data structures are used in a
> single-threaded way, why should we not hope for the performance to be
> comparable?

If you can guarantee single-threaded use, then you can just use ST and
implement the ephemeral structure, right?

> It may not be easy, but just saying "they are persistent" is not
> really an excuse.

You can generally make a persistent data structure with the same
asymptotic bounds as the ephemeral structure, but the constant hidden
inside the O() will generally be worse.