Re: Raw string literals in Emacs lisp.

[David Kastrup <dak@gnu.org>]

"Stephen J. Turnbull" <turnbull@sk.tsukuba.ac.jp> writes:

> Matthew Plant writes:
>
>  > Although this data is convincing in some respects, I would like to note
>  > that xemacs is dead.
>
> The reports of the death of XEmacs are premature.
>
>  > The download off their main page did not even have any
>  > raw string literals.
>
> XEmacs 21.4 will never have them.

Drawing the following excerpts from
<URL:http://www.xemacs.org/Releases/index.html>:

Arguably, having the last "stable release" made in 2009, having no
"Gamma release" described as

    Note: XEmacs 21.4 has been promoted to stable, and there currently
    is no gamma series. Plans for the next release are in the works.

    The gamma series of releases is satisfactorily stable for most
    sophisticated users. Most Linux or *BSD users should get the best
    results from the gamma series, and we strongly recommend it to the
    ``tester'' distributions like NetBSD current, Debian sid, Mandrake
    Cooker, Red Hat Rawhide, and so on. XEmacs will be ready when they
    are!

    The gamma series of releases is the candidate for promotion to a
    stable series. Although we do not promote the code base to gamma
    while there are known critical bugs in the code base, to attempt to
    meet schedules we also do promote fairly quickly once we've fixed
    the last known critical bug. Everybody does this, and everybody
    knows that despite the best efforts of the developers, ``point oh''
    releases typically still have bugs in them. The gamma concept simply
    acknowledges this.

at all slated to become stable, and having the current "Beta release"
branch 21.5 started in 2001 with the description

    The beta series of releases is for testers. Users should read the
    XEmacs Beta mailing list, <xemacs-beta@xemacs.org>. Users should
    prepare themselves for crashes, data loss, freezes, and other
    unpleasant events. The beta series contains much experimental code,
    and fairly large changes may be introduced directly into the code
    base. These are announced as they happen on xemacs-beta. Wannabe
    developers may also want to follow the XEmacs Patches
    <xemacs-patches@xemacs.org> and XEmacs CVS Commits
    <xemacs-cvs@xemacs.org> mailing lists for up-to-the-minute details
    about the state of the code base.

is making Debian look like a fast-paced project.  Reports of XEmacs
being dead may be exaggerated, but it does look a lot like suspended
animation.

> Sure, you can do a lot for readability as PCRE or Python regexps have
> done, but regexps are unreadable almost by design, and those regexp
> syntaxes benefit from rawstrings, too.  Almost anything (that doesn't
> involve changing the meaning of existing legal programs) that improves
> readability of regexps is worthwhile.
>
> Rawstrings are cheap and effective.

When rawstrings are supported, it becomes more expedient to recognize
things like \n and \t, probably also \f in regexps (\b is already
taken).  At the current point of time, they just evaluate to n and t.
That makes input of tabs and newlines in raw strings a nuisance and a
potential source of errors.

It's not actually an issue with rawstrings as such, but rather of their
use within regexps.

-- 
David Kastrup