Where in the world is String.trim_leading/1?

I tried to look up the definition of String.trim_leading/1 from GitHub, because I wanted to clarify the meaning of “Unicode whitespaces” in the documentation. However, all I saw was the single line

defdelegate trim_leading(string), to: String.Break

and I couldn’t find the module String.Break on GitHub or HexDocs. Does anybody know where are the actual definitions of String.trim_leading/1 or String.Break located?

See the Unicode folder: https://github.com/elixir-lang/elixir/tree/master/lib/elixir/unicode

Those modules are slow to compile, so they are in their own directory.


Thanks. On ll.292-294 of https://github.com/elixir-lang/elixir/blob/master/lib/elixir/unicode/properties.ex :

for codepoint <- whitespace do
  def do_trim_leading(<<unquote(codepoint), rest::bits>>), do: do_trim_leading(rest)

This is cool… I didn’t know one can generate functions programatically like this at compile time!