In-place update

[Keith Wansbrough <Keith.Wansbrough@cl.cam.ac.uk>]

> > > Doesn't haskell 98 allow in place updating e.g; for records?
> >
> > [see next message]
> >
> I have read this message and now I have the following question:
>      Does this mean that a compiled program written in a strict functional
> language will be faster than the "same" program compiled with thelazy
> functional language Haskell 98

No, a strict language has exactly the same problem.  It's generally a "problem" for all (pure) functional languages... just like in mathematics.  It makes no sense in mathematics to write "x=x+1"; you always write something like "x(2)=x(1)+1".  It's the same in a pure functional language.

It does however mean that programs written in this style in a functional language will perform slower than programs written in a similar style in an imperative language.  This doesn't necessarily mean there isn't a better way to write it in the functional language, just that the algorithm in your favourite algorithms book is tuned for C rather than Haskell.

HTH.

--KW 8-)
-- 
: Keith Wansbrough, MSc, BSc(Hons) (Auckland) ------------------------:
: PhD Student, Computer Laboratory, University of Cambridge, England. :
:  (and recently of the University of Glasgow, Scotland. [><] )       :
: Native of Antipodean Auckland, New Zealand: 174d47' E, 36d55' S.    :
: http://www.cl.cam.ac.uk/users/kw217/  mailto:kw217@cl.cam.ac.uk     :
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