弗雷格的正则表达式文字

Question

在Frege中用于指定正则表达式文字的重音符号的unicode代码是什么？

Answer 1

The character is called Acute Accent and the unicode for that is 00B4 . In ubuntu, you can type that using Ctrl + Shift + u and then type 00B4 then space . However you don't really have to use that if your regex literal is more than one character in which case you can just use apostrophes.

Quoting the doc :

Regular expression literals have type Regex and are written:

 ´\b(foo|bar)\b´       -- string enclosed in grave accents
 '\w+'                 -- string with length > 1 enclosed in apostrophes
The notation with the apostrophes has been introduced because many have a hard time entering a grave accent mark on their terminal. However, it is not possible to write a regular expressions with length 1 this way, because then the literal gets interpreted as Char literal. (One can write something like '(?:X)' for a Regex that matches a single 'X').