CLHS: Declaration IGNORE, IGNORABLE

#

Declaration IGNORE, IGNORABLE

Syntax:

``(`ignore` {``var`` |`` (``function`` fn``)``}``*``)``

``(`ignorable` {``var`` |`` (``function`` fn``)``}``*``)``

Arguments:

var---a variable name.

fn---a function name.

Valid Context:

declaration

Binding Types Affected:

variable, function

Description:

The ignore and ignorable declarations refer to for-value references to variable bindings for the vars and to function bindings for the fns.

An ignore declaration specifies that for-value references to the indicated bindings will not occur within the scope of the declaration. Within the scope of such a declaration, it is desirable for a compiler to issue a warning about the presence of either a for-value reference to any var or fn, or a special declaration for any var.

An ignorable declaration specifies that for-value references to the indicated bindings might or might not occur within the scope of the declaration. Within the scope of such a declaration, it is not desirable for a compiler to issue a warning about the presence or absence of either a for-value reference to any var or fn, or a special declaration for any var.

When not within the scope of a ignore or ignorable declaration, it is desirable for a compiler to issue a warning about any var for which there is neither a for-value reference nor a special declaration, or about any fn for which there is no for-value reference.

Any warning about a ``used'' or ``unused'' binding must be of type style-warning, and may not affect program semantics.

The stream variables established by with-open-file, with-open-stream, with-input-from-string, and with-output-to-string, and all iteration variables are, by definition, always ``used''. Using `(declare (ignore` v`))`, for such a variable v has unspecified consequences.

See Also:

declare

The following X3J13 cleanup issues, not part of the specification, apply to this section:

- IGNORE-USE-TERMINOLOGY:VALUE-ONLY
- DOTIMES-IGNORE:X3J13-MAR91

Copyright 1996-2005, LispWorks Ltd. All rights reserved.