F# 注释错误

Question

我在自学 F# 我通常是一名 C# 程序员。

我正在尝试使用 (**)在我阅读章节时为自己做笔记，但我从评论本身中得到了一个错误。

module Characters

let vowels = ['a', 'e', 'i', 'o', 'u']

printfn "Hex u0061 = '%c'" '\u0061'

(*  <------------Error is here, is 'End of file in string embedded in comment begun at or before here'
    Character Escape Sequences

    Character       Meaning
    -------------------------------
    \'              Single Quote
    \"              Double Quote
    \\              Backslash
    \b              Backspace
    \n              Newline
    \r              Carriage Return
    \t              Horisontal Tab
*)

这是否将评论视为字符串意味着我必须转义我的评论？

Answer 1

F#琐事时间!这是设计使然。 Block comments can be nested, and strings within a block comment are tokenized like regular strings .在这种情况下，有效的字 rune 字算作“字符串”。

所以这些是有效的块注释:

(* "embedded string, this --> *) doesn't close the comment" *)
(*  (* nested *) comment *)
(* quote considered to be in char literal '"' is ok *)

但这些都不是

(* "this string is not closed *)
(* " this quote --> \" is escaped inside a string *)

好像这还不够疯狂，还有 special treatment for operators which begin with * 自 (*)等通常被认为是块注释的开始或结束。

(* I can talk about the operator (*) without ending my comment *)

AFAIK，这些都是从 ML 继承的(嵌套注释肯定是，不确定字符串)。

因此，出于您的目的，您可能想要执行以下操作:

(*  Character       Meaning
    -------------------------------
    " \' "          Single Quote
    " \" "          Double Quote

    or

    '\''            Single Quote
    '"'             Double Quote
*)