[Haskell] Top-level <-
ger at informatik.uni-bremen.de
Thu Nov 25 04:07:20 EST 2004
John Meacham wrote:
> Now, my mdo proposal as written would have "hello" outputed exactly once
> at module start up time no matter what, whether x is demanded or not. it
> is equivalant to a program transformation that collects all the top
> level initializers and declarations, puts them all in a mdo block and
> runs it with the semantics explained in the fixIO paper. (with a
> deterministic, but partially undefined order)
What happens if you write the following?
y <- f
x <- ....
let f = something depending on x
Will it know to evaluate x before y, or is this not allowed?
What about if the assignments to y and x occur in different modules? Will the
RTS have to analyse the dependencies to work out which order to run the assignments
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