F＃不完整的類型結構引起的結構化構造

Question

所以，我有一個函數corners，我想要一個二維數組（帶有縮寫類型的HieghtMap）並返回記錄類型的座標列表。起初，我不指定matrixLocal的類型，這導致 System.Exception: Operation could not be completed due to earlier error  The type 'matrixLocal' is not defined. at 30,28

現在，我指定的類型，我得到這個新的錯誤

 Syntax error in labelled type argument at 30,39 
Incomplete structured construct at or before this point in 
interaction. Expected incomplete structured construct at or before 
this point, ';', ';;' or other token. 

我相信這是由於farside（因爲它即使它自己也不起作用），但我不知道爲什麼，因此我在這裏。我發現的關於後一個錯誤的其他問題似乎不適用於這種情況（一個是關於縮進，另一個是關於嘗試在循環中重新定義變量）。

的代碼：

module DiamondSquare = 

//create type for defining shapes 
///Defined by length of the side of a square that the ovject is inscribed in 
type Shape = 
    | Square of int 
    | Diamond of int 

///the X and Y position 
type Coordinates = {X: int; Y: int} 

///The Hieghtmap of a given chunk of region as a series of floats that are the offset from the base hieght 
//was HieghtMap = HieghtMap of float[,], but was changed so that any 2D float array would be accepted 
type HieghtMap = float[,] 

//Create matrix of zeroes of chunk size to initilize this variable 
let matrix = Array2D.zeroCreate<float> 9 9 

//locate center of shape 
// since each shape is a square, or can be inscribed within one, pass it a matrix and find the 
// coordinate of the center (same value for i and j) 
///Finds center of shape inscribed within a square. Takes a matrix, returns coordinates for within the matrix 
let locateCenterpoint matrixLocal = 
    let coord = int ((Array2D.length1 matrixLocal) - 1)/2 
    {X = coord; Y = coord;} 

//locate corners of a shape that is inscribed in a square 
///Returns list of corner values for a given shape. Takes a matrix and returns a list of Coordinates 
let corners shape:Shape matrixLocal:HieghtMap = 
    let farSide = Array2D.length1 matrixLocal - 1 
    let getSquareCorners = 
     {X = 0; Y = 0}::{X = farSide; Y = 0}::{X = 0; Y = farSide}::{X = farSide; Y = farSide}::[] 
    let getDiamondCorners = 
     {X = farSide/2; Y = 0}::{X = farSide; Y = farSide/2}::{X = farSide/2; Y = farSide}::{X = 0; Y = farSide/2}::[] 
    match shape with 
    | Square -> getSquareCorners 
    | Diamond -> getDiamondCorners 
    | _ -> None 

Answer 1

當定義在F＃的值，則第一個冒號表示值名稱和類型聲明的起動結束。例如：

let f x y : string = ... 

在此聲明，string是返回類型的功能，和不類型y參數。爲了類型聲明應用到列表中的一個值，使用括號：

let f x (y: string) = ... 

這樣，string是y類型。

爲了您的具體情況，看看這個行：

let corners shape:Shape matrixLocal:HieghtMap = 

看到的問題是什麼？ Shape正在被解析爲corners函數的返回類型，並且這會使後續的matrixLocal:HeightMap變得無意義。要修復，請使用圓括號：

let corners (shape:Shape) (matrixLocal:HieghtMap) =