F＃將活動模式與擴展元組匹配

Question

在子集中，我在紅色的波浪曲線中得到以下錯誤。
Type mismatch. Expecting a Range -> Choice but given a Range * Range -> Choice

是否有某種類型的註釋我可以添加到SubSet匹配，所以我不必使用fst和snd？如果不是，是否有意支持這種語法？

type Range = {min : int64; max : int64} 

let (|Before|After|BeforeOverlap|AfterOverlap|SuperSet|SubSet|) (x, y) = 
    if x.min > y.max then After 
    elif x.min >= y.min then 
     if x.max <= y.max then SubSet 
     else AfterOverlap 
    elif x.max < y.min then Before 
    elif x.max <= y.max then BeforeOverlap 
    else SuperSet 

let useOldx x xe ye =() 

let diff (xe:IEnumerator<Range>) (ye:IEnumerator<Range>) = 
    match xe.Current, ye.Current with 
    | After as tuple ->() 
    | Before as t -> if xe.MoveNext() then useOldx (fst t) xe ye 
    | SuperSet as t -> 
     let x, y = t 
     if xe.MoveNext() then useOldx x xe ye 
    | SubSet as x, y -> if xe.MoveNext() then useOldx x xe ye 
    | _ ->() 

Answer 1

你可以這樣做：

| (x,y) & SubSet -> if xe.MoveNext() then useOldx x xe ye 

，或者你可以這樣做：

open System.Collections.Generic 

type Range = {min : int64; max : int64} 

let (|Before|After|BeforeOverlap|AfterOverlap|SuperSet|SubSet|) (x, y) = 
    if x.min > y.max then After 
    elif x.min >= y.min then 
     if x.max <= y.max then SubSet(x,y) 
     else AfterOverlap 
    elif x.max < y.min then Before 
    elif x.max <= y.max then BeforeOverlap 
    else SuperSet 

let useOldx x xe ye =() 

let diff (xe:IEnumerator<Range>) (ye:IEnumerator<Range>) = 
    match xe.Current, ye.Current with 
    | After as tuple ->() 
    | Before as t -> if xe.MoveNext() then useOldx (fst t) xe ye 
    | SuperSet as t -> 
     let x, y = t 
     if xe.MoveNext() then useOldx x xe ye 
    | SubSet(x, y) -> if xe.MoveNext() then useOldx x xe ye 
    | _ ->()