Pattern match on any single UTF-8 character

Question

I would like to have a function clause that matches any single UTF-8 character.

I can match on specific characters like this

def foo("a") do
  "It's an a"
end

But I cannot determine if it possible to do the same for any single UTF8 character.

My current solution is to split the string to a char list and pattern match on that, but I was curious if I could skip that step.

Answer 1

You can do this with:

def char?(<<c::utf8>>), do: true
def char?(_), do: false

Note that this only matches a binary with a single character, to match on the next character in a string, you can just do:

def char?(<<c::utf8, _rest::binary>>), do: true

Answer 2

From the Regex docs:

The modifiers available when creating a Regex are: ...

• unicode (u) - enables Unicode specific patterns like \p and changes modifiers like \w, \W, \s and friends to also match on Unicode. It expects valid Unicode strings to be given on match
• dotall (s) - causes dot to match newlines and also set newline to anycrlf; the new line setting can be overridden by setting (*CR) or (*LF) or (*CRLF) or (*ANY) according to :re documentation

So you might try: ~r/./us

From http://elixir-lang.org/crash-course.html

In Elixir, the word string means a UTF-8 binary and there is a String module that works on such data

So I think you should be good to go.