Klaus Ostermann schrieb:
> data SimpleExp = Num Int | Add SimpleExp SimpleExp
>
> data LabelledExp = LNum Int String | LAdd LabelledExp LabelledExp String
>
> I wonder what would be the best way to model this situation without
> repeating the structure of the AST.
How about the following simple parameterization?
data Exp label = LNum Int label
| LAdd (Exp label) (Exp label) label
type SimpleExp = Exp ()
mkNum i = LNum i ()
type LabelledExp = Exp String
Cheers Christian
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