Asterisk(cormullion.github.io) |
The connection with asterisk/Asterix makes it so much better.
FWIW, I only realized last year, ~30 years after I read the books, that Idefix was named thus because of "idée fixe"[0].
Ah, the unexpected depth of a children comic book!
- Panoramix (panorama) - Abraracourcix (a bras racourcis) - Bonnemine, Assurancetourix, Agecanonix, etc.
Realistically I've never seen most of those symbols in any book I've ever read. If you're regularly using more than 2 footnotes a page, you're probably better of numbering them and moving the references to the end of the chapter or book.
Also, some citation styles make heavy use of footnotes.
(1) The paragraph marker ¶ is called a pilcrow or alinea.
(2) The names sin and cos were invented by William Oughtred, whose 1631 book Clavis Mathematicae, The Key to Mathematics was the first use in print of the saltire (, a rotated +) for multiplication.
(3) Traditionally serif faces included a six-pointed asterisk, while sans serif asterisks had five, but in practice this is no longer an observed convention.
"." is the wildcard character. "*" is a quantifier meaning 0 or more of the previous.
ie.: in most OSes you can use * as wildcard for filename.
file.*
will refer to all files named "file" with any extension
.zip
will refer to all files with any name as long as they have the zip extension
is a wildcard in most contexts while "." is wildcard only in regex that i know.
Perhaps this is where the use of * as the wild-card character comes from. I find regular expressions can induce swearing, occasionally.
The article is about the asterisk character, and the connection to the wild-card seems legit. But the sentence "I find regular expressions can induce swearing, occasionally" (which I agree fully with!) hints towards the idea that the * is used as a wildcard in regular expressions, which I think isn't quite true.
[1] https://en.wikipedia.org/wiki/Glob_(programming)#Compared_to...
Star-free languages are regular languages without the Kleene star.
https://en.wikipedia.org/wiki/Star-free_language
But I'm not an expert in formal languages and maybe you are.
Star-free languages are a strict subset of the set of regular languages, so there exist regular languages that require the Kleene star to be represented as a regular expression; indeed the Wikipedia article you linked gives an example.
It's perhaps worth noting that neither regular expressions nor globs are themselves regular languages: they are just used to define regular languages. Consider that regular expressions usually require some form of parenthetical notation, and that languages with matched parentheses cannot be regular as a trivial consequence of the pumping lemma.