emacs/elisp:哈希(磅、数字符号、octothorp)符号是做什么用的? [英] emacs/elisp: What is the hash (pound, number sign, octothorp) symbol used for?
问题描述
这是做什么的?
(add-hook 'compilation-mode-hook #'my-setup-compile-mode)
...它和
(add-hook 'compilation-mode-hook 'my-setup-compile-mode)
推荐答案
没有区别:
(eq 'my-add #'my-add)
产量 t
#
可以用在 lambda
表达式的前面,指示字节编译器可以对以下表达式进行字节编译,请参阅 匿名函数.但是在符号的情况下没有什么可以编译的.
The #
can be used in front of a lambda
expression indicating to the byte-compiler that the following expression can be byte compiled, see the docs for Anonymous Functions. But there's nothing to compile in the case of a symbol.
一般在打印的表示 以及左尖括号 (<) 表示打印的对象是描述(但无法读取).例如:
In general, it is used in the printed representation along with the left angle bracket (<) to indicate that the object printed is a description (but cannot be read). For example:
#<buffer foo.txt>
它也被读者用在结构中来表示圆形结构.请参阅阅读循环对象语法的文档.
It is also used in constructs by the reader to represent circular structures. See the docs for Read Syntax for Circular Objects.
然后你可以用它来表示 整数基,例如<代码>#x2c ->44.
And then you have its use for denoting the base for integers, e.g. #x2c -> 44
.
我敢肯定还有更多.
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