Data.Array.Mutable.Linear.Array is unnecessarily strict about linear-base HOT 5 CLOSED

I think we should have unboxed and boxed variants. This could be useful for cache sometimes.

from linear-base.

Is the issue fixed by

-readMutArr :: MutArr# a -> Int -> a
+readMutArr :: MutArr# a -> Int -> (# a #)
 readMutArr mutArr (I# ix) =
-   case doRead of (# _, a #) -> a
+   case doRead of (# _, a #) -> (# a #)
   where
     doRead = runRW# $ \stateRW -> readArray# mutArr ix stateRW

?

from linear-base.

Using a continuation would also help

readMutArr :: MutArr# a -> Int -> (a -> b) -> b
readMutArr mutArr (I# ix) f =
  case doRead of (# _, a #) -> f a
  where
    doRead = runRW# $ \stateRW -> readArray# mutArr ix stateRW

I think

readMutArr arr i $ \a ->
  seq (writeMutArr arr i 'b'`) a

would play effects in the right order, although it is still possible to write the incorrect

let a = readMutArr arr i id
 in seq (writeMutArr arr i 'b') a

from linear-base.

Is the issue fixed by

I think so. Must be tried 🙂

from linear-base.

Is the issue fixed by

I think so. Must be tried

It is :). I applied the change on @facundominguez's first comment, followed the types until it compiles, then added a test case on #143.

from linear-base.