RE: [External] : Re: Keywords as function arguments for control flow

[Drew Adams]

> Your example uses symbols not keywords.

And one can Ask Emacs.  This is what the Elisp manual
has to say about keywords:

  A symbol whose name starts with a colon (':') is
  called a keyword symbol. These symbols automatically
  act as constants, and are normally used only by
  comparing an unknown symbol with a few specific
  alternatives. See "Variables that Never Change".

https://www.gnu.org/software/emacs/manual/html_node/elisp/Symbol-Type.html

That "Variables that Never Change" link takes you here:

https://www.gnu.org/software/emacs/manual/html_node/elisp/Constant-Variables.html

where it says this:

  Function: keywordp object ¶
  function returns t if object is a symbol whose
  name starts with ':', interned in the standard
  obarray, and returns nil otherwise.