GHCi, version 6.10.1 crashes without message
Heiko Studt
studt at fmi.uni-passau.de
Tue Jan 13 15:52:21 EST 2009
PPS: Why does your mailinglist not set the Reply-To header?
@Roman Cheplyaka: Sorry for double mailing.
Am 13.01.2009 schrieb Roman Cheplyaka:
> > | f x y z = a + b*c + b + fun c
> > | where a = x * y + z
> > | b = c * fun x
> > | c = a * b
> > | fun x = x * x + 1
> >
> > The query to die was "f 1 2 3".
> Your program loops for the following reason:
> to compute f, you need to compute c
> to compute c, you need to compute b
> to compute b, you need to compute c again!
> Haskell cannot solve equations (or, at least, not formulated in this
> way), so it understands definition of f as the rules to compute things
> like a, b, c. No wonder evaluation of f never terminates.
The problem is not it does not terminate. It terminates. GHCi terminates
inclusivly (maybe by simpathy? ;-)). As Chris Smith wrote it faults the
stack.
I tried to get the thing some smaller and therefor to the point,
I should have done this before I assume:
| let f = c where {c = c}
at "f",
| let f = f in f
kills GHCi immidiatelly.
| let f 0 = f 0 in f 0
simply does not terminate (as it should be).
MFG (With friendly regards)
Heiko Studt
PS: Funny way for quitting with two keystroke. ;-)
--
Heiko Studt <studt at fmi.uni-passau.de>
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