RE: plists, alists, and hashtables

[Drew Adams]

> I've been advocating for readtable and reader macros as a mean for _end_
> _user_ extension, not because I support adding syntaxes to lisp.

Yes, precisely.

> Additionnal syntaxes can be useful, and should only be used,
> for end users and DSL implementing a domain with pre-existing
          ^^^^^     ^^^
> _extensive_ use of that syntax.

Yes.  What other languages must do at language-design time, Lisp
users can do with Lisp code - at language-design time for a DSL.

My guess is that those not getting this have never used or heard of
something like the Common Lisp reader, where you-the-programmer can
define reader macros and pretty much create the syntax - whatever
syntax - you want.

We Lisp _users_ can make good use of syntax-defining constructs.
But Lisp itself does not need any syntactic embellishment, which
would in fact work against its nature.

> But maps are not something out[side] of this lisp world.  They
> existed from the start as a-list, then p-list and then hash-tables.
> They are a basic data structure perfectly integrated to an
> algorithmic programming language, and don't constitute a different,
> Domain Specific Language. For this reason, they should use the usual
> lisp sexps.

A good example.  But the same can be said for *any* construct, not just
maps.  We should not add special syntax to Lisp to support any construct.

We should not, and we should not need to.  The need that is not yet met
in Emacs Lisp is to give users themselves ways to define syntax.  Emacs
Lisp could really benefit from having a Common Lisp-like reader (in
particular, `set-macro-character' or similar).