[Haskell-cafe] [newbie question] Memoization automatic in Haskell?

[Hugh Perkins]

On Jan 12, 2008 10:54 PM, Henning Thielemann
<lemming at henning-thielemann.de> wrote:
>
> On Sat, 12 Jan 2008, Hugh Perkins wrote:
>
> > I guess that Haskell's referential transparence means the answers to
> > the isPerfectSquare will be cached, ie automatically memoized? (not
> > sure if is correct term?)
>
> http://www.haskell.org/haskellwiki/Memoization
>

Interesting... but I dont understand... I thought that referential
transparence meant that once the answer to a function has been
calculated once, it will always be the same, and that the interpreter
can, and will, cache this answer?

So, if I call f( 20 ) once, for some, arbitrary, f, it will have to go
away and calculate f(20), but if I call it multiple times, it will
just return the value it already calculated?