[Haskell-cafe] Lazy Lists and IO

[Derek Elkins]

On Wed, 2007-07-11 at 22:33 +0200, Chaddaï Fouché wrote:
> 2007/7/11, Andrew Coppin <andrewcoppin at btinternet.com>:
> >
> > Ouch! That's gotta sting...
> >
> > I wasn't aware that this function was so leathal. I use it constantly
> > all the time...
> >
> 
> It isn't that "lethal" usually. It's only because he was using it on
> an infinite stream that it hurt so much... If you use it on a normal
> stdin or a hGetContents on a file it will be fine (though you will
> lose the advantage of its laziness, for example constant memory
> treatment).
> 

Nevertheless, length is a function you should rarely use.