Function: cl--const-expr-val

cl--const-expr-val is a byte-compiled function defined in cl-macs.el.gz.

Signature

(cl--const-expr-val X)

Documentation

Return the value of X known at compile-time.

If X is not known at compile time, return nil. Before testing whether X is known at compile time, macroexpand it completely in macroexpand-all-environment.

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/cl-macs.el.gz
(defun cl--const-expr-val (x)
  "Return the value of X known at compile-time.
If X is not known at compile time, return nil.  Before testing
whether X is known at compile time, macroexpand it completely in
`macroexpand-all-environment'."
  (let ((x (macroexpand-all x macroexpand-all-environment)))
    (if (macroexp-const-p x)
        (if (consp x) (nth 1 x) x))))