Haskell Platform proposal: Add the vector package

Roman Leshchinskiy rl at cse.unsw.edu.au
Tue Jul 17 11:28:42 CEST 2012

Simon Marlow wrote:
> The fact that you can't do arbitrary side effects in ST follows from the
> definition of safety and the fact that runST injects ST computations
> into pure computations.  So there's really no design choice here.  The
> same applies to the Par monad, and any monad that injects into pure
> computations.

I disagree about there not being a choice. As I wrote, if the injection
function is Unsafe (i.e., not Trustworthy), then there is no safe way to
inject the computations and then those computations can do what they want
(as far as Safe Haskell is concerned) because they can't be safely
executed anyway. So it really depends on whether or not the injection
function has been declared Trustworthy.


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