You may want to try tail-recursion version
while test body = liftM reverse $ loop []
where
loop acc = do
(cond,res) <- body
(if test cond then loop else return) (res:acc)
Regards,
Vivian McPhail
<[EMAIL PROTECTED] To: [EMAIL PROTECTED]
ise.net.nz> cc:
Sent by: Subject: [Haskell] Monadic Loops
[EMAIL PROTECTED]
ll.org
06/17/2004 04:16 AM
Hi,
I've implemented a Neural Net simulator which needs to repeat a training
loop many times. For this I used a while function:
while test body = do
(cond,res) <- body
if (test cond) then do rs <- while test body
return (res:rs)
else return [res]
However, when I run the program, the interpreter falls over after a few
thousand iterations, running out of space. I think that this is because the
Monadic implementation of the while loop actually nests functions of type
(a -> M b) and there is a maximum ?stack size.
Is there a better way to implement (possibly infinite) loops in Haskell?
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