Re: Predicate for true lists

[Alex Branham]

On Wed 10 Apr 2019 at 05:32, Eli Zaretskii <address@hidden> wrote:

>> From: "Basil L. Contovounesios" <address@hidden>
>> Date: Tue, 09 Apr 2019 21:12:49 +0100
>> Cc: address@hidden
>> 
>> diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi
>> index 8ebe47d9ad..826818c380 100644
>> --- a/doc/lispref/internals.texi
>> +++ b/doc/lispref/internals.texi
>> @@ -1031,10 +1031,13 @@ Writing Emacs Primitives
>>  @file{lisp.h} contains the definitions for some important macros and
>>  functions.
>>  
>> -  If you define a function which is side-effect free, update the code
>> -in @file{byte-opt.el} that binds @code{side-effect-free-fns} and
>> address@hidden so that the compiler optimizer
>> -knows about it.
>> +  If you define a function which is side-effect free, give it a
>> address@hidden @code{side-effect-free} declaration (@pxref{Declare
>> +Form}) or function property (@pxref{Symbol Plists}) so that the
>> +compiler optimizer knows about it.  Alternatively, you can update the
>> +code in @file{byte-opt.el} that binds @code{side-effect-free-fns} and
>> address@hidden, but this approach is less
>> +modular and no longer encouraged.
>
> This should have a @cindex entry for "side-effect-free" and other
> symbols referenced here.  Bonus points for adding some minimal
> explanation what does "side-effect free function" mean.
>
> Thanks.

Isn't this in direct contradiction with (info "(elisp) Standard
Properties") which states that side-effect-free should not be set?:

‘side-effect-free’
     A non-‘nil’ value indicates that the named function is free of
     side-effects, for determining function safety (*note Function
     Safety::) as well as for byte compiler optimizations.  Do not set
     it.

Thanks,
Alex