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Diffstat (limited to 'testsuite/tests/gadt/gadt4.hs')
-rw-r--r-- | testsuite/tests/gadt/gadt4.hs | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/testsuite/tests/gadt/gadt4.hs b/testsuite/tests/gadt/gadt4.hs new file mode 100644 index 0000000000..0d78135597 --- /dev/null +++ b/testsuite/tests/gadt/gadt4.hs @@ -0,0 +1,18 @@ +{-# LANGUAGE GADTs #-} + +module Main where + +data Term a where + Lit :: Int -> Term Int + IsZero :: Term Int -> Term Bool + If :: Term Bool -> Term a -> Term a -> Term a + + +eval :: Term a -> a +eval (Lit n) = n +eval (IsZero t) = eval t == 0 +eval (If t1 t2 t3) = if eval t1 then eval t2 else eval t3 + +term = If (IsZero (Lit 1)) (Lit 2) (Lit 3) + +main = print (eval term)
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