forall

What does the `forall` keyword in Haskell/GHC do?

I'm beginning to understand how the forall keyword is used in so-called "existential types" like this: data ShowBox = forall s. Show s => SB s This is only a subset, however, of how forall is used and I simply cannot wrap my mind around its use in things like this: runST :: forall a. (forall s. ST s a) -> a Or explaining why these ...

Using Contract.ForAll in Code Contracts

Okay, I have yet another Code Contracts question. I have a contract on an interface method that looks like this (other methods omitted for clarity): [ContractClassFor(typeof(IUnboundTagGroup))] public abstract class ContractForIUnboundTagGroup : IUnboundTagGroup { public IUnboundTagGroup[] GetAllGroups() { Contract.Ensu...

PLINQ update failed

Hi, sorry for my English. So, here is my question I'm trying to update DataTable by PLINQ Here is my code DataTable table = new DataTable(); table.Columns.Add(new DataColumn("val", typeof(decimal))); int N = 1000000; for (int i = 0; i < N; i++) table.Rows.Add(new object[] { i }); table.AsEnumerable().AsParallel().ForAll(row => row["...

How can I ensure that my Fortran FORALL construct is being parallelized?

I've been given a 2D matrix representing temperature points on the surface of a metal plate. The edges of the matrix (plate) are held constant at 20 degrees C and there is a constant heat source of 100 degrees C at one pre-defined point. All other grid points are initially set to 50 degrees C. My goal is to take all interior grid points...