proposal: add 'unsafeCoerce'
Malcolm.Wallace at cs.york.ac.uk
Tue Nov 21 04:40:08 EST 2006
Taral <taralx at gmail.com> writes:
> On 11/20/06, Malcolm Wallace <Malcolm.Wallace at cs.york.ac.uk> wrote:
> > newtype Wrapper a = Wrap a
> > convert :: [a] -> [Wrapper a]
> > convert xs = map Wrap xs
> Interesting! Looks like the compiler lacks rules for optimizing "map
> id" &c.\
And not all compilers have optimisation phases.
> Your coercion does assume that the underlying runtime doesn't have
> some kind of type-tag implementation of type classes.
I believe this is guaranteed by the definition of newtype in the
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