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Improved examples for documentation of 'eq'

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* doc/lispref/objects.texi (Equality Predicates):
Remove incorrect and/or misleading examples, add new ones,
and display them more compactly to save space.
This commit is contained in:
Mattias Engdegård 2025-11-03 12:57:15 +01:00
parent df3706a3c3
commit 11860fe936
1 changed files with 26 additions and 59 deletions
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85
doc/lispref/objects.texi
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@ -2369,56 +2369,40 @@ regards it as its bare symbol when @code{symbols-with-pos-enabled} is
non-@code{nil} (@pxref{Symbols with Position}).
@example
@group
(eq 'foo 'foo)
@result{} t
@end group
(eq 'abc 'abc) @result{} t
(eq 'abc 'ABC) @result{} nil
(eq ?A ?A) @result{} t
(eq 3 3) @result{} t
@end example
@group
(eq ?A ?A)
@result{} t
@end group
Equal non-fixnum numbers may or may not be the same object:
@group
(eq 3.0 3.0)
@result{} t @r{or} nil
;; @r{Equal floats may or may not be the same object.}
@end group
@example
(eq 3.0 3.0) @result{} t @r{or} nil
(eq (expt 10 50) (expt 10 50)) @result{} t @r{or} nil
@end example
@group
(eq (make-string 3 ?A) (make-string 3 ?A))
@result{} nil
@end group
Newly created mutable objects are distinct:
@group
(eq "asdf" "asdf")
@result{} t @r{or} nil
;; @r{Equal string constants or may not be the same object.}
@end group
@example
(eq (list 1 2 3) (list 1 2 3)) @result{} nil
(eq (point-marker) (point-marker)) @result{} nil
@end example
@group
(eq '(1 (2 (3))) '(1 (2 (3))))
@result{} nil
@end group
Equal constants of other types may or may not be the same object:
@group
(setq foo '(1 (2 (3))))
@result{} (1 (2 (3)))
(eq foo foo)
@result{} t
(eq foo '(1 (2 (3))))
@result{} nil
@end group
@example
(eq "abc" "abc") @result{} t @r{or} nil
(eq '(1 2 3) '(1 2 3)) @result{} t @r{or} nil
(eq [1 2 3] [1 2 3]) @result{} t @r{or} nil
@end example
@group
(eq [(1 2) 3] [(1 2) 3])
@result{} nil
@end group
Unless they are the same literal constant:
@group
(eq (point-marker) (point-marker))
@result{} nil
@end group
@example
(let ((x "abc")) (eq x x)) @result{} t
(let ((x '(1 2 3))) (eq x x)) @result{} t
(let ((x [1 2 3])) (eq x x)) @result{} t
@end example
@noindent
@ -2473,38 +2457,21 @@ the converse is not always true.
(equal "asdf" "asdf")
@result{} t
@end group
@group
(eq "asdf" "asdf")
@result{} nil
@end group
@group
(equal '(1 (2 (3))) '(1 (2 (3))))
@result{} t
@end group
@group
(eq '(1 (2 (3))) '(1 (2 (3))))
@result{} nil
@end group
@group
(equal [(1 2) 3] [(1 2) 3])
@result{} t
@end group
@group
(eq [(1 2) 3] [(1 2) 3])
@result{} nil
@end group
@group
(equal (point-marker) (point-marker))
@result{} t
@end group
@group
(eq (point-marker) (point-marker))
@result{} nil
@end group
@end example
The @code{equal} function compares strings and bool-vectors by value.