Declaration—a declare expression; not evaluated.
forms—an implicit progn.
results—the values of the forms.
Sequentially evaluates a body of forms in a lexical environment where the given declarations have effect.
(defun sample-function (y) ;this y is regarded as special (declare (special y)) (let ((y t)) ;this y is regarded as lexical (list y (locally (declare (special y)) ;; this next y is regarded as special y)))) → SAMPLE-FUNCTION (sample-function nil) → (T NIL) (setq x '(1 2 3) y '(4 . 5)) → (4 . 5) ;;; The following declarations are not notably useful in specific. ;;; They just offer a sample of valid declaration syntax using LOCALLY. (locally (declare (inline floor) (notinline car cdr)) (declare (optimize space)) (floor (car x) (cdr y))) → 0, 1
;;; This example shows a definition of a function that has a particular set ;;; of OPTIMIZE settings made locally to that definition. (locally (declare (optimize (safety 3) (space 3) (speed 0))) (defun frob (w x y &optional (z (foo x y))) (mumble x y z w))) → FROB ;;; This is like the previous example, except that the optimize settings ;;; remain in effect for subsequent definitions in the same compilation unit. (declaim (optimize (safety 3) (space 3) (speed 0))) (defun frob (w x y &optional (z (foo x y))) (mumble x y z w)) → FROB
The special
declaration may be used with locally
to affect references to, rather than bindings of, variables.
If a locally
form is a top level form, the body forms
are also processed as top level forms. See Section 3.2.3 (File Compilation).