shadow symbol-names &optional package ⇒ t
| symbol-names | a designator for a list of string designators. |
| package | a package designator.
The default is the current package. |
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.
(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
shadow changes the state of the package system in such a way that the package consistency rules do not hold across the change.
Current state of the package system.
If a symbol with a name in symbol-names already exists in package, but by inheritance, the inherited symbol becomes shadowed_3 by a newly created internal symbol.