Hi,
I’ve a read-eval-print loop based program that
I’ve been trying to make more robust by catching and responding to any
exceptions that might be thrown; mainly using Control.Exception.evaluate and
Control.Exception.catch. However, I noticed that once I catch a non-termination
type of error and take care of it, ghc throws me a “thread blocked
indefinitely” message and immediately crashes in the next read-eval-print
attempt right away. I was trying to come up with a small bit of code to
demonstrate this when I noticed ghci behaves the same:
c:\>ghci
___ ___ _
/ _ \ /\ /\/ __(_)
/ /_\// /_/ / / |
| GHC Interactive, version 6.2.1, for Haskell 98.
/ /_\\/ __ / /___|
| http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|
Type :? for help.
Loading package base ... linking ... done.
Prelude> let x=x in x
*** Exception: <<loop>>
Prelude> 3
Fail: thread blocked indefinitely
c:\>
The first message is great. However _expression_ ‘3’
causes ghci to crash after that. (This is happening on Windows, by the way. I
don’t have a *nix lying around to try it out.)
So, my questions is: How do we address this issue, if
at all possible. If possible, why doesn’t ghci do it?
Thanks,
-Levent.
