Special symbols are
nonalphanumeric characters, or pairs of such characters, that have fixed
meanings. The following single characters are special symbols.
# $
& ' ( )
* + , ? . / : ; < =
> @ [ ]
^ { }
The following character pairs are
also special symbols.
(* (.
*) .) .. //
:= <= >= < >
The left bracket [ is equivalent to the character pair of left parenthesis and period (. ; the right bracket ] is equivalent to the character pair of period and right parenthesis .) .
The left-parenthesis plus asterisk
and asterisk plus right-parenthesis (* *) are equivalent to the left and right
brace { } .
Notice that !, " (double quotation marks), %, ?, \, _ (underscore), | (pipe), and ~ (tilde) are not special characters.
Fundamental syntactic elements:
Overview
特殊符号是非字母非数字的字符或字符对,特殊符号有固定含义。下面的单个字符都是特殊符号:
# $
& ' ( )
* + , ? . / : ; < =
> @ [ ]
^ { }
下面的字符对也是特殊符号:
(* (.
*) .) .. //
:= <= >= < >
左方括号 [ 和右方括号 ] 分别等价于字符对 (. 和 .) (左圆括号加句点以及句点加右圆括号)。
左花括号 { 和右花括号 } 分别等价于字符对 (* 和 *) (左圆括号加星号以及星号加右圆括号)。
需要注意的是,!(叹号)、”(双引号)、%(百分比符号)、?(问号)、\(反斜杠)、_(下划线)、|(管道)以及~(代字号)不是特殊符号。