bug#49647: 27.2; Reference Manual sec. 10.2.4; Incorrect example for indirect-function

bug#49647: 27.2; Reference Manual sec. 10.2.4; Incorrect example for indirect-function

[Scott Marks]

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If one copies the example:


Here is how you could define indirect-function in Lisp:


(defun indirect-function (function)

  (if (symbolp function)

      (indirect-function (symbol-function function))

    function))


this code will throw due to infinite recursion when invoked as


(indirect-function nil)


The fix is obvious: wrap (symbolp function) with (and function ...)


I don't think this would distract from the point of the example.


Hope this helps

Scott


In GNU Emacs 27.2 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60
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bug#49647: 27.2; Reference Manual sec. 10.2.4; Incorrect example for indirect-function

[Michael Heerdegen]

Scott Marks <scott.c.marks@gmail.com> writes:

> If one copies the example:

You mean from the manual, (info "(elisp) Function Indirection") I think.

>  Here is how you could define indirect-function in Lisp:
>
>  (defun indirect-function (function)
>
>    (if (symbolp function)
>
>        (indirect-function (symbol-function function))
>
>      function))
>
> this code will throw due to infinite recursion when invoked as
>
> (indirect-function nil)
>
> The fix is obvious: wrap (symbolp function) with (and function ...)

In my opinion your analysis is correct and the fix is good.

I leave it to the second reader to make the change.


Michael.

bug#49647: 27.2; Reference Manual sec. 10.2.4; Incorrect example for indirect-function

[Lars Ingebrigtsen]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> In my opinion your analysis is correct and the fix is good.
>
> I leave it to the second reader to make the change.

Now done.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no