sizeFM type

Carsten Schultz carsten at codimi.de
Tue Apr 27 13:35:34 EDT 2004


On Mon, Apr 26, 2004 at 06:42:20AM -0400, David Roundy wrote:
> On Sun, Apr 25, 2004 at 11:38:19PM +0200, Tomasz Zielonka wrote:
> > On Sun, Apr 25, 2004 at 04:12:25PM -0400, David Roundy wrote:
> > > 
> > > On the other hand, since they are still 32 bit computers, any given
> > > application can still only access 4G of memory.  This issue will only be a
> > > problem on 64 bit platforms which have a 32 bit Int.
> > 
> > Here is a funny program that gives wrong result because of length
> > returning Int on a 32-bit computer.
> > 
> >     import Data.List
> >     main = print (length (genericTake 5000000000 (repeat ())))
> > 
> > Running it shows
> > 
> >     $ ./A
> >     705032704
> > 
> > But this is a strange piece of code and I agree that it will hardly be a
> > problem on a 32 bit platform.
> 
> In fact, the only way this will be a problem is if your list is lazy and
> consumed by the length function, but it's hard to see how that could happen
> except in strange example code.  That is, it's hard to imagine when you'd
> need to know the length of a data structure you don't need...

Think `wc -l'.

Greetings,

Carsten

-- 
Carsten Schultz (2:38, 33:47), FB Mathematik, FU Berlin
http://carsten.codimi.de/
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