url.el custom 变量绑定问题

Emacs-general
,
12

算的，但是这个问题的情况似乎比较特殊。

考虑这个简单的例子：（lexical-binding默认开启）

(let ((x 1))
  (lambda () x))

求值得到#[nil (x) ((x . 1))]，let的词法绑定生效。

但是如果前面加上

(defvar x 0)
(let ((x 1))
  (lambda () x))

得到是#[nil (x) (t)]。x变成了动态绑定的，let的词法绑定不生效。

我想这是defvar的问题。defvar的文档里说：

If INITVALUE is provided, the ‘defvar’ form also declares the variable as “special”, so that it is always dynamically bound even if ‘lexical-binding’ is t. If INITVALUE is missing, the form marks the variable “special” locally (i.e., within the current lexical scope, or the current file, if the form is at top-level), and does nothing if ‘lexical-binding’ is nil.

那么defcustom是不是有这个问题呢？它的文档里说：

This macro uses defvar' as a subroutine, which also marks the variable as \"special\", so that **it is always dynamically bound** **even when lexical-binding’ is t**.

相关问题我看到有一个相关的帖子之前讨论过：

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