declaration-specifier—a declaration specifier.
Establishes the declaration specified by declaration-specifier in the global environment.
Such a declaration, sometimes called a global declaration or a proclamation, is always in force unless locally shadowed.
Names of variables and functions within declaration-specifier refer to dynamic variables and global function definitions, respectively.
The next figure shows a list of declaration identifiers
that can be used with proclaim
.
An implementation is free to support other (implementation-defined) declaration identifiers as well.
(defun declare-variable-types-globally (type vars)
(proclaim `(type ,type ,@vars))
type)
;; Once this form is executed, the dynamic variable *TOLERANCE*
;; must always contain a float.
(declare-variable-types-globally 'float '(*tolerance*))
→ FLOAT
declaim, declare, Section 3.2 (Compilation)
Although the execution of a proclaim
form
has effects that might affect compilation, the compiler does not make
any attempt to recognize and specially process proclaim
forms.
A proclamation such as the following, even if a top level form,
does not have any effect until it is executed:
(proclaim '(special *x*))
If compile time side effects are desired, eval-when
may be useful.
For example:
(eval-when (:execute :compile-toplevel :load-toplevel) (proclaim '(special *x*)))
In most such cases, however, it is preferrable to use declaim
for
this purpose.
Since proclaim
forms are ordinary function forms,
macro forms can expand into them.