If x :: t, and t :: Unlifted, then
let x = e in e'
has a value that depends on evaluating e regardless of its use
in e' (or other things in the let, if they exist). It would be like writing
let !x = e in e'
today.
-- Dan
On Fri, Sep 4, 2015 at 5:41 PM, Roman Cheplyaka
On 05/09/15 00:23, Edward Z. Yang wrote:
I would certainly agree that in terms of the data that is representable, there is not much difference; but there is a lot of difference for the client between Force and a strict field. If I write:
let x = undefined y = Strict x in True
No error occurs with:
data Strict = Strict !a
But an error occurs with:
data Strict = Strict (Force a)
At what point does the error occur here? When evaluating True?
What about the following two expressions?
const False (let x = undefined y = Strict x in True)
let x = undefined y = const False (Strict x) in True
Roman
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