compiler-errors - 将内联与显式成员约束结合时出现奇怪的错误

Question

(更新:我添加了一个重现示例)

代码如下所示:

type Lib =
    static member inline tryMe (a: ^a) = 
        let name = (^a: (static member name: string) ())
        name

type Test =
    struct 
        val Value: string
        new v = {Value = v}
    end
    static member inline name with get() = "HiThere"
    static member works(a:Test) = Lib.tryMe a

这将“正常工作”并编译。但是，如果您稍微扩展一下，例如如下所示:

/// Does a bounds check and raises an error if bounds check is not met
let inline checkBounds f (g: 'b -> ^c) (tp: ^a) = 
    let convertFrom = (^a: (static member name: string) ())
    let convertTo = (^c: (static member name : string) ())
    let value =  (^a: (member Value: 'b) tp)
    if f value then
        g value
    else 
        failwithf "Cannot convert from %s to %s." convertFrom convertTo


type ConverterA =
    struct 
        val Value: sbyte
        new v = { Value = v }
    end

    static member inline name with get() = "converter-a"
    static member inline convert (x: ConverterA) : ConverterB = 
        checkBounds ((>=) 0y) (byte >> ConverterB) x

and ConverterB =
    struct 
        val Value: byte
        new v = { Value = v }
    end
    static member inline name with get() = "converter-b"

它会引发一大堆虚假的 FSharp 编译器错误。

error FS1114: The value 'Foo.Bar.name' was marked inline but was not bound in the optimization environment

error FS1113:The value 'name' was marked inline but its implementation makes use of an internal or private function which is not sufficiently accessible

warning FS1116: A value marked as 'inline' has an unexpected value

error FS1118: Failed to inline the value 'name' marked 'inline', perhaps because a recursive value was marked 'inline'

我还没有看到其他内联函数发生这种情况。我不确定这里会发生什么。如果我稍微改变一下，例如删除 convertTo行及其依赖项，它编译得很好。

在 FSI 中运行代码时也不会出现错误，即使 FSI 设置为 --optimize .

我可以通过删除 inline 来解决它.对于这种类型的字段，无论如何都无关紧要，即使 F# 没有内联，JIT 也会内联它们。

这是编译器错误吗？或者我的代码中是否有错误，或者我没有意识到对显式成员约束的一些限制？

Answer 1

您需要重新排序，以便您使用的函数在您使用它们的地方是已知的，否则 F# 编译器似乎不知道要内联什么。正如您在此答案下方的评论中所说，如果您问我，这是一个错误。

/// Does a bounds check and raises an error if bounds check is not met
let inline checkBounds f (g: 'b -> ^c) (tp: ^a) = 
    let convertFrom = (^a: (static member name: string) ())
    let convertTo = (^c: (static member name : string) ())
    let value =  (^a: (member Value: 'b) tp)
    if f value then
        g value
    else 
        failwithf "Cannot convert from %s to %s." convertFrom convertTo

type ConverterB =
    struct 
        val Value: byte
        new v = { Value = v }
    end
    static member inline name with get() = "converter-b"

and ConverterA =
    struct 
        val Value: sbyte
        new v = { Value = v }
    end

    static member inline name with get() = "converter-a"
    static member inline convert (x: ConverterA) : ConverterB = 
        checkBounds ((>=) 0y) (byte >> ConverterB) x