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emacselisp

What is the colon (:) in Emacs lisp?

I'm not talking about keyword variables (those that are prefixed with a colon), I'm talking about just :. Example from an ielm session:

ELISP> :
:

It seems to be a variable whose value is : which makes it sort of act like a noop like it does in shell. I'm just curious if there's any documentation about it. I can't look it up with describe-variable...

Solution

  • : is a keyword, that is, a Lisp symbol whose print name begins with ":". It satisfies predicate keywordp.