CODEWITHSUNDEEP
emacselisp
Jisang Yoo
Jisang Yoo

Reputation: 3745

defvar without INITVALUE

The first tip in Warning Tips - GNU Emacs Lisp Reference Manual:

Try to avoid compiler warnings about undefined free variables, by adding dummy defvar definitions for these variables, like this: (defvar foo) Such a definition has no effect except to tell the compiler not to warn about uses of the variable foo in this file.

What is a scenario where someone would want no effect and yet want to disable the warning about the free variable? Whenever I got warnings about undefined free variables, it was always the case that either I forgot to put (defvar foo initvalue docstring) or I misspelled a local variable name.

Upvotes: 2

Views: 136

Answers (1)

Drew
Drew

Reputation: 30701

Your question is why/when to suppress such warnings. The answer is: in either of these situations:

  • The variable is defined elsewhere, and you know that the library defining it will be loaded before the code actually tries to use the variable.

  • You want to declare that the variable is a "special" variable, that is, it is to be bound dynamically, not lexically.

Upvotes: 2

Related Questions