From: YugaEgo Date: Tue, 30 Nov 2021 13:03:32 +0000 (+0100) Subject: Format and index concept 'predicate' in ELisp Intro X-Git-Tag: emacs-28.0.90~22 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=cd9dd26d24;p=emacs.git Format and index concept 'predicate' in ELisp Intro * doc/lispintro/emacs-lisp-intro.texi (Wrong Type of Argument): Add index and format definition (bug#52197). Copyright-paperwork-exempt: yes --- diff --git a/doc/lispintro/emacs-lisp-intro.texi b/doc/lispintro/emacs-lisp-intro.texi index e3064580580..bd5decff669 100644 --- a/doc/lispintro/emacs-lisp-intro.texi +++ b/doc/lispintro/emacs-lisp-intro.texi @@ -2146,9 +2146,10 @@ number---the number of characters the location is from the beginning of the buffer.) In Emacs Lisp, @code{+} can be used to add the numeric value of marker positions as numbers. +@cindex @samp{predicate} defined The @samp{p} of @code{number-or-marker-p} is the embodiment of a practice started in the early days of Lisp programming. The @samp{p} -stands for ``predicate''. In the jargon used by the early Lisp +stands for @dfn{predicate}. In the jargon used by the early Lisp researchers, a predicate refers to a function to determine whether some property is true or false. So the @samp{p} tells us that @code{number-or-marker-p} is the name of a function that determines