如何在泛型函數中定義 F# 泛型函數參數？

Question

let getLogicalWithDoubleLevelElement<'E when 'E :> DoubleLevelElement>
    (logicalModifier : InletPosition * OutletPosition -> Logical)
    (logical : Logical) =

我需要logicalModifier是泛型函數，類型與getLogicalWithDoubleLevelElement類型參數相同。

如何定義？

Answer 1

如果您需要將顯式多態函數作為參數傳遞，那么在 F# 中執行此操作的唯一方法是使用具有泛型方法的新類型：

type LogicalModifier =
    abstract MakeLogical<'E when 'E :> DoubleLevelElement> : InletPosition * OutletPosition -> Logical

let getLogicalWithDoubleLevelElement<'E when 'E :> DoubleLevelElement>
    (logicalModifier : LogicalModifier)
    (logical : Logical) = ... logicalModifier.MakeLogical<'E> ...