On 2/23/08, Bulat Ziganshin wrote: [about my question about keyboard interrupts]

you should store thread id of thread running interpreter and send async exception to it. control.concurrent is probably contains all required functions

Most splendid! Here's what I did

data MyInterrupt = MyInt Int instance Typeable MyInterrupt where typeOf x = typeOf (0 :: Int)

catcher :: MyInterrupt -> IO () catcher e = hPutStrLn stderr "interrupt!"

then later, in the REPL

catchDyn (evalAndPrint env True line) (\e -> catcher e)

and in the initialization

mysighandler tid = Catch (throwDynTo tid (MyInt 0))

and

myTID <- myThreadId installHandler sigINT (mysighandler myTID) Nothing installHandler sigQUIT (mysighandler myTID) Nothing doREPL env

I had to add the "MyInterrupt" stuff because GHC was complaining about ambiguous types, initially I had just "(\e -> hPutStrLn stderr (show e))" as the second arg of the catchDyn. And try it in the self-test... Now test number/string conversions... this'll take a bit longer interrupt! lisp> It works! Cool! This is worth bumping the version number :-) Many thanks! Uwe

Thanks, I'll try that. -- Uwe On 2/24/08, Ryan Ingram wrote:

This is pretty cool, but I have one warning:

On Sat, Feb 23, 2008 at 4:37 PM, Uwe Hollerbach wrote:

...

...

data MyInterrupt = MyInt Int instance Typeable MyInterrupt where typeOf x = typeOf (0 :: Int)

I am pretty sure that this makes Dynamic unsound; you could accidentally cast from an Int to a MyInterrupt or vice versa. Try this instead:

...

data MyException = Interrupt deriving Typeable

then you can safely use throwDyn and catchDyn on this type.

-- ryan