1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
module Test.VeriFuzz.Graph.Random where
import Data.Graph.Inductive (Graph, LNode, LEdge, mkGraph)
import Test.QuickCheck (Arbitrary, Gen, arbitrary, generate, infiniteListOf, suchThat, listOf, scale, resize)
import Test.VeriFuzz.Types
arbitraryEdge :: (Arbitrary e) => Int -> Gen (LEdge e)
arbitraryEdge n = do
x <- with $ \a -> a < n && a > 0 && a /= n-1
y <- with $ \a -> x < a && a < n && a > 0
z <- arbitrary
return (x, y, z)
where
with = suchThat . resize n $ arbitrary
randomDAG :: (Arbitrary l, Arbitrary e, Graph gr)
=> Int -- ^ The number of nodes
-> IO (gr l e) -- ^ The generated graph. It uses Arbitrary to
-- generate random instances of each node
randomDAG n = do
list <- generate . infiniteListOf $ arbitrary
l <- generate . infiniteListOf $ arbitraryEdge n
return . mkGraph (nodes list) $ take (2*n) l
where
nodes l = (zip [0..n] $ take n l)
|
