Hello!
I have a program that is using ST.Strict, which works fine.
However, the program needs to be extended, and to do that,
lazy evaluation is needed. As a result of that, I have switched
to ST.Lazy to be able to do stuff like
foo y = do
x <- something
xs <- foo (y+1)
return (x:xs)
As Ryan points out, this will not do what you want. But that is incidental, not essential:
foo y = do
x <- something
fmap (x:) $ foo (y+1)
Questioning my own reasoning, I must apologize. I was wrong, these two programs are identical and both do what you want.
Any references to the state after the infinite chain of foos will result in _|_, but as long as "something" is the only place that state calls occur, you will be fine.
I also suspect that ST.Lazy should be no less defined than ST.Strict in all cases, modulo unsafe operations of course (you aren't doing those, are you?), so you have encountered a bug. Minimize the test case and submit a bug report :-)
Luke