Testing for ASDF 3.3.2 and beyond?

[Faré]

On Fri, Mar 2, 2018 at 1:05 PM, Robert Goldman <rpgoldman at sift.net> wrote:
> So as I see it we have three options for the *shared-readtable*
>
> Your original option -- the "initial-ish" readtable (since we can't control
> when ASDF is loaded)
Usually ASDF is loaded before any significant other software is. If
the user insists in modifying the initial readtable early, he's
probably on to something.

> My proposal: a copy of the standard readtable. We should consider what might
> happen in this case if ASDF is reloaded or upgraded. I don't know if option
> #1 has this same issue.
In either case, definitely use defvar rather than defparameter, unless
you're also going to clear-registered-systems at every update.

> An unmodifiable standard readtable. I don't believe that this is portably
> possible, is it? There's no ANSI method (unless I've overlooked something)
> to make a readtable unmodifiable, and there's no way to access the standard
> readtable portably (since it isn't required to be unique).
>
It's not portable for unmodifiability to be enforced, but it's
certainly non-conformant to try to modify even when the
implementations fails silently later rather than catches you
immediately. So far as I know, only SBCL, ECL, Allegro, CMUCL make it
unmodifiable. Maybe file bugs for other relevant implementations?

> I believe my proposal, #2, is the most portable of all of the solutions, but
> I am still open to correction.
>
For some definition of "portable". I know that some systems rely on
e.g. CCL or MCL extensions #$ or #_ — but they could be made to use
the *initial-readtable* that we definitely are going to save anyway.

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
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