W3C HTTP規範中「1＃」標記的展開

我正在閱讀W3C HTTP header spec以查找某些HTTP標頭的確切格式。像大多數規格一樣，HTTP標頭規格使用BNF來正式指示特定的標頭格式。W3C HTTP規範中「1＃」標記的展開

但我困惑的「1#」令牌的使用，如：

Cache-Control = "Cache-Control" ":" 1#cache-directive

鑑於背景下，似乎預示着一個逗號分隔的列表。但是我從來沒有見過這個令牌用過，我找不到它的定義。規範本身並沒有按照我所能看到的來定義它。

當然，我不幸的是不能簡單地爲這種事情做一個Google search。由於查詢解析器的侷限性，即使是全球性的商業級搜索引擎也無法生成我想要的信息，這是極少數情況之一。

來源

2014-12-04 Siler

來源：RFC2616 Chapter 2.1 Augmented BNF

A construct "#" is defined, similar to "*", for defining lists of 
    elements. The full form is "<n>#<m>element" indicating at least 
    <n> and at most <m> elements, each separated by one or more commas 
    (",") and OPTIONAL linear white space (LWS). This makes the usual 
    form of lists very easy; a rule such as 
    (*LWS element *(*LWS "," *LWS element)) 
    can be shown as 
    1#element 
    Wherever this construct is used, null elements are allowed, but do 
    not contribute to the count of elements present. That is, 
    "(element), , (element) " is permitted, but counts as only two 
    elements. Therefore, where at least one element is required, at 
    least one non-null element MUST be present. Default values are 0 
    and infinity so that "#element" allows any number, including zero; 
    "1#element" requires at least one; and "1#2element" allows one or 
    two.

編輯：原來的問題相連，qoutes此答案是基於RFC 2616。然而，引用的RFC在今年已經被一些較新的RFC廢棄了。 1#令牌的定義已在RFC7030中更新。請參閱here的規範來源和here的答案，以便提及此更改。請也知道，關於相關通道的勘誤存在here

來源

2014-12-04 21:40:48 Rangad

1）這不是一個W3C規範。

2）RFC 2616已經過時。與RFC 7230相關的是什麼。有關語法的解釋，請參閱http://greenbytes.de/tech/webdav/rfc7230.html#abnf.extension。

來源

2014-12-05 07:53:15

W3C HTTP規範中「1＃」標記的展開

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