# polysemy-RandomFu
## Summary
- Polysemy effect and intepreters to use the random-fu library in a polysemy effect union (like an mtl stack).
- Includes an MTL "absorber" (see https://github.com/isovector/polysemy-zoo/blob/master/src/Polysemy/MTL.hs) for
to random-fu ```MonadRandom``` typeclass.
## Example (from the tests)
```haskell
import Polysemy
import Polysemy.RandomFu
import qualified Data.Random as R
import qualified Data.Random.Source.PureMT as R
getRandomInts :: Member RandomFu r => Int -> Sem r [Int]
getRandomInts nDraws =
sampleRVar $ M.replicateM nDraws (R.uniform 0 (100 :: Int))
main :: IO ()
main = do
seed <- R.newPureMT
putStrLn . show $ runM . runRandomIOPureMT (R.pureMT seed) $ getRandomInts 5
```
should print a list of 5 pseudo-random integers.
They will be different each time you run because the ```newPureMT``` function
returns a different seed each time it's called. If you replace that seed in
the ```R.pureMT``` argument to ```runRandomIOPureMT``` with a fixed number
then you will get the *same* pseudo-random sequences each time. This can be
useful for testing.
## Notes
- See the tests (in https://github.com/adamConnerSax/Polysemy-Extra/blob/master/polysemy-RandomFu/test/RandomFuSpec.hs)
for more details about how to use this effect