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authoraarne <aarne@cs.chalmers.se>2008-11-11 09:21:59 +0000
committeraarne <aarne@cs.chalmers.se>2008-11-11 09:21:59 +0000
commitdb18350b1e55f7edfca8f02b0b233a6a7dcbb1ec (patch)
tree525fd7fc741c53a4021d1edd9538452ee388e4d3 /examples/tutorial/embedded/TransferDef.hs
parentca59050abc8efccfb59b93cfbd8da93556605928 (diff)
fixed some tutorial grammars and updated embedded section (JavaScript and web TODO)
Diffstat (limited to 'examples/tutorial/embedded/TransferDef.hs')
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diff --git a/examples/tutorial/embedded/TransferDef.hs b/examples/tutorial/embedded/TransferDef.hs
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+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 [] = []