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[Emacs-diffs] master dfa922d: Clarify eq on floats


From: Paul Eggert
Subject: [Emacs-diffs] master dfa922d: Clarify eq on floats
Date: Mon, 2 Apr 2018 15:19:39 -0400 (EDT)

branch: master
commit dfa922dd844c7af966a42b949aee32248ce4e8a2
Author: Paul Eggert <address@hidden>
Commit: Paul Eggert <address@hidden>

    Clarify eq on floats
    
    * doc/lispref/objects.texi (Equality Predicates):
    Say that two floats with the same values might or might not be eq.
---
 doc/lispref/objects.texi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/lispref/objects.texi b/doc/lispref/objects.texi
index af74062..78a7dcc 100644
--- a/doc/lispref/objects.texi
+++ b/doc/lispref/objects.texi
@@ -2083,6 +2083,10 @@ strings), two arguments with the same contents or 
elements are not
 necessarily @code{eq} to each other: they are @code{eq} only if they
 are the same object, meaning that a change in the contents of one will
 be reflected by the same change in the contents of the other.
+For other types of objects whose contents cannot be changed (e.g.,
+floats), two arguments with the same contents might or might not be
+the same object, and @code{eq} returns @code{t} or @code{nil}
+depending on whether the Lisp interpreter created one object or two.
 
 @example
 @group
@@ -2096,6 +2100,12 @@ be reflected by the same change in the contents of the 
other.
 @end group
 
 @group
+(eq 3.0 3.0)
+     @result{} t @r{or} nil
+;; @r{The result is implementation-dependent.}
address@hidden group
+
address@hidden
 (eq "asdf" "asdf")
      @result{} nil
 @end group



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