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Diffstat (limited to 'examples/tutorial/embedded/TransferDef.hs')
| -rw-r--r-- | examples/tutorial/embedded/TransferDef.hs | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/examples/tutorial/embedded/TransferDef.hs b/examples/tutorial/embedded/TransferDef.hs new file mode 100644 index 000000000..37d81c6dc --- /dev/null +++ b/examples/tutorial/embedded/TransferDef.hs @@ -0,0 +1,26 @@ +module TransferDef where + +import PGF (Tree) +import Query -- generated from GF + +transfer :: Tree -> Tree +transfer = gf . answer . fg + +answer :: GQuestion -> GAnswer +answer p = case p of + GOdd x -> test odd x + GEven x -> test even x + GPrime x -> test prime x + +value :: GObject -> Int +value e = case e of + GNumber (GInt i) -> fromInteger i + +test :: (Int -> Bool) -> GObject -> GAnswer +test f x = if f (value x) then GYes else GNo + +prime :: Int -> Bool +prime x = elem x primes where + primes = sieve [2 .. x] + sieve (p:xs) = p : sieve [ n | n <- xs, n `mod` p > 0 ] + sieve [] = [] |
