Nondeterminism.md

Non-determinism

In Edh the for-from-do loop, combined with generator procedures, are much like a procedural version of Haskell's list Monad, modeling non-determinism as well.

Take the example in this blog post

satExample :: Bool
satExample = or $ do
  x1 <- [True, False] -- "guess" is replaced by bind (<-)
  x2 <- [True, False]
  {- ... -}
  xN <- [True, False]
  pure (formula x1 x2 {- ... -} xN)

This is exactly the same thing in Edh

method satExample() or ({generator _ ()
  for x1 from [true, false] do
  for x2 from [true, false] do
  # ...
  for xN from [true, false] do
  yield formula (
    x1, x2,
    # ...,
    xn
  )
})

The utility procedure or's Edh implementation:

method or ( possibles ) {
  for predict from possibles() do
    predict -> return true
  return false
}