F＃tail.Head plus lists

Question

我正在尝试编写一些用于操作多项式的F＃代码，因为我希望将列表的重复元素组合到单个元素中，这是相关代码：

type PolynomialElem(Coeff : double, Power : int) =
  member x.Coeff = Coeff
  member x.Power = Power
let rec removeDuplicates (inlist:list<PolynomialElem>) (outlist:list<PolynomialElem>) =   
    match inlist with
        |head:: tail ->if head.Power = tail.Head.Power then
                            PolynomialElem(head.Coeff + tail.Head.Coeff) :: removeDuplicates tail.Tail
                        else
                            head :: (removeDuplicates(tail))
        |[] -> []      

这会产生两组不同的错误：

The head.Coeff + tail.head.Coeff produces a type mismatch saying "type double * int doesn't match type double"

编译器也对我连接列表的方式不满意，说：

This expression was expected to have type PolynomialElem list but here has type PolynomialElem list -> PolynomialElem list      

任何帮助？

Answer 1

这是编译的代码：

type PolynomialElem(Coeff : double, Power : int) =
  member x.Coeff = Coeff
  member x.Power = Power
let rec removeDuplicates (inlist:list<PolynomialElem>)  =   
    match inlist with
        |head:: tail ->if head.Power = tail.Head.Power then
                            PolynomialElem(head.Coeff + tail.Head.Coeff, head.Power) :: removeDuplicates tail.Tail
                        else
                            head :: (removeDuplicates(tail))
        |[] -> []      

你忘记了第二个参数（Power）传递给PolynomialElem

您有一些未使用/需要的'outlist'参数。