17 lines
500 B
Haskell
17 lines
500 B
Haskell
data Term =
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Nat Integer
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| Abs String Term -- EAbs Abstraction
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| Inv Term Term -- EApp Invocation (a.k.a. Application) of a function
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| Var String -- EVar a variable
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| Add
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pretty x = case x of
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(Abs name term) -> "L" ++ name ++ "." ++ pretty term
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(Inv func param) -> "(" ++ pretty func ++ " " ++ pretty param ++ ")"
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(Var name) -> name
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Add -> "Add"
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-- example
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-- >>> pretty (Abs "x" $ Abs "y" $ Inv (Inv Add (Var "x")) (Var "y"))
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-- "Lx.Ly.((Add x) y)"
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