Declaration Scope (original) (raw)

ANSI Common Lisp 3 Evaluation and Compilation 3.3 Declarations

3.3.4 Declaration Scope

Declarations can be divided into two kinds: those that apply to the_bindings_ of variables or functions; and those that do not apply to bindings.

A declaration that appears at the head of a binding _form_and applies to a variable or function _binding_made by that form is called a bound declaration; such a declaration affects both the binding and any references within the scope of the declaration.

Declarations that are not bound declarations are called**free declarations**.

A free declaration in a form F1 that applies to a _binding_for a name N established by some form _F2_of which F1 is a _subform_affects only references to N within F1; it does not to apply to other references to N outside of F1, nor does it affect the manner in which the binding of N by F2 is established.

Declarations that do not apply to bindings can only appear as free declarations.

The scope of a bound declaration is the same as the_lexical scope_of the binding to which it applies; for special variables, this means the scope that the _binding_would have had had it been a lexical binding.

Unless explicitly stated otherwise, the scope of a free declaration includes only the body subforms of the form at whose head it appears, and no other subforms. The scope of free declarations specifically does not include initialization forms for bindings established by the form containing the declarations.

Some iteration forms include step, end-test, or result subforms that are also included in the _scope_of declarations that appear in the iteration form. Specifically, the iteration forms and subforms involved are:

3.3.4.1 Examples of Declaration Scope