[Haskell-cafe] Is it safe to use unsafePerformIO here?

[Daniel Fischer]

Am Dienstag 15 September 2009 22:17:00 schrieb Cristiano Paris:
> On Tue, Sep 15, 2009 at 10:12 PM, Ross Mellgren <rmm-haskell at z.odi.ac> wrote:
> > Wouldn't seq b only force (at minimum) the first character of the file?
>
> I think it force the evaluation of the "Cons" in the String but not
> the characters therein.

It evaluates the String far enough to know whether it's "" or (_:_), that is, to weak head 
normal form. It doesn't look at any character, but it forces at least one character to be 
read from the file.

>
> Cristiano