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1 files changed, 21 insertions, 0 deletions

diff --git a/progs/demo/pfac.hs b/progs/demo/pfac.hs
new file mode 100644
index 0000000..516fc85
--- /dev/null
+++ b/progs/demo/pfac.hs
@@ -0,0 +1,21 @@
+   
+-- This is a parallel varient of factorial
+
+module Main where
+
+fac :: Int -> Int
+fac 0 = 1
+fac n = pfac 1 n
+
+pfac :: Int -> Int -> Int
+pfac low high | low == high     = low
+              | low + 1 == high = (low * high)
+              | otherwise       = pfac low mid * pfac (mid + 1) high
+    where
+       mid = (high + low) `div` 2
+
+main = appendChan stdout "Type in N: " abort $
+       readChan stdin abort $ \ input ->
+       appendChan stdout (show (fac (read (head (lines input))))) abort done
+
+