mirror of
https://github.com/idris-lang/Idris2.git
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48 lines
1.1 KiB
Idris
48 lines
1.1 KiB
Idris
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import System.FFI
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pfn : String -> String
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pfn fn = "C:" ++ fn ++ ",libstruct"
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Point : Type
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Point = Struct "point" [("x", Int), ("y", Int)]
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NamedPoint : Type
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NamedPoint = Struct "namedpoint" [("name", Ptr String), ("pt", Point)]
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%foreign (pfn "getString")
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getStr : Ptr String -> String
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%foreign (pfn "mkPoint")
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mkPoint : Int -> Int -> Point
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%foreign (pfn "freePoint")
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freePoint : Point -> PrimIO ()
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%foreign (pfn "mkNamedPoint")
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mkNamedPoint : String -> Point -> PrimIO NamedPoint
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%foreign (pfn "freeNamedPoint")
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freeNamedPoint : NamedPoint -> PrimIO ()
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showPoint : Point -> String
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showPoint pt
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= let x : Int = getField pt "x"
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y : Int = getField pt "y" in
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show (x, y)
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showNamedPoint : NamedPoint -> String
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showNamedPoint pt
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= let x : String = getStr (getField pt "name")
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p : Point = getField pt "pt" in
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show x ++ ": " ++ showPoint p
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main : IO ()
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main = do let pt = mkPoint 20 30
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np <- primIO $ mkNamedPoint "Here" pt
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setField pt "x" (the Int 40)
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putStrLn $ showPoint pt
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putStrLn $ showNamedPoint np
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primIO $ freeNamedPoint np
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primIO $ freePoint pt
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