X-Git-Url: https://mattmccutchen.net/match/match.git/blobdiff_plain/fd0d2377785ca843a46b0050a7351dac82c84777..066d7f5355c79a94b6d3a6fb2008e0a506b289c7:/program/RandomizedMonad.hs

diff --git a/program/RandomizedMonad.hs b/program/RandomizedMonad.hs
index 37f2b98..f3b50d4 100644
--- a/program/RandomizedMonad.hs
+++ b/program/RandomizedMonad.hs
@@ -3,9 +3,12 @@ module RandomizedMonad (
 	runRandom, runRandomStd, runRandomNewStd,
 	mrandomR, mrandom,
 	withProb,
-	filterRandomized
+	filterRandomized,
+	indRandomArray
 ) where
 import System.Random
+import Data.Array.IArray
+import Data.Ix
 
 -- Needs -XRank2Types
 newtype Randomized a = Randomized (forall g. RandomGen g => (g -> a))
@@ -59,3 +62,11 @@ filterRandomized :: (a -> Bool) -> Randomized a -> Randomized a
 filterRandomized f ra = do
 	a <- ra
 	if f a then return a else filterRandomized f ra
+
+-- Randomized array with elements chosen independently following a given
+-- randomized element.
+indRandomArray :: (IArray a e, Ix i) =>
+	(i, i) -> Randomized e -> Randomized (a i e)
+indRandomArray bds rElement = do
+	list <- sequence $ replicate (rangeSize bds) rElement
+	return (listArray bds list)