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ANSI Common Lisp  11 Packages 11.2 Dictionary of Packages
- Syntax:
-
shadow
symbol-names &optional package
 t
- Arguments and Values:
-
symbol-names - a designator for
a list of string designators.
package - a package designator.
The default is the current package.
- Description:
-
shadow assures that symbols with names given
by symbol-names are present
in
the package.
Specifically, package is searched for symbols
with the names supplied by symbol-names.
For each such name, if a corresponding symbol
is not present in package (directly, not by inheritance),
then a corresponding symbol is created with that name,
and inserted into package as an internal symbol.
The corresponding symbol, whether pre-existing or newly created,
is then added, if not already present, to the shadowing symbols list
of package.
- Examples:
-
(package-shadowing-symbols (make-package 'temp)) NIL
(find-symbol 'car 'temp) CAR, :INHERITED
(shadow 'car 'temp) T
(find-symbol 'car 'temp) TEMP::CAR, :INTERNAL
(package-shadowing-symbols 'temp) (TEMP::CAR)
(make-package 'test-1) #<PACKAGE "TEST-1">
(intern "TEST" (find-package 'test-1)) TEST-1::TEST, NIL
(shadow 'test-1::test (find-package 'test-1)) T
(shadow 'TEST (find-package 'test-1)) T
(assert (not (null (member 'test-1::test (package-shadowing-symbols
(find-package 'test-1))))))
(make-package 'test-2) #<PACKAGE "TEST-2">
(intern "TEST" (find-package 'test-2)) TEST-2::TEST, NIL
(export 'test-2::test (find-package 'test-2)) T
(use-package 'test-2 (find-package 'test-1)) ;should not error
- Side Effects:
-
shadow changes the state of the package system in such a
way that the package consistency rules do not hold across the change.
- Affected By:
-
Current state of the package system.
- See Also:
-
package-shadowing-symbols,
Section 11.1 Package Concepts
- Notes:
-
If a symbol with a name in symbol-names already exists
in package, but by inheritance, the inherited symbol becomes
shadowed3 by a newly created internal symbol.
- Allegro CL Implementation Details:
-
None.
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