Re: [NonGNU ELPA] New package: sqlite3

[Lynn Winebarger]

On Tue, Mar 21, 2023 at 12:53 PM Philip Kaludercic <philipk@posteo.net> wrote:
> I really, really have no idea what you are getting at.  As in "ok, but
> what is your intent in explaining this?".
>
> Are you trying to propose that Emacs circumvents the SQLite API (that as
> far as I see uses strings) by constructing statement objects manually?

Not at all.  I don't think I can communicate via email the power of
generative programming techniques, and why basing them on simple
string concatenation is a bad idea, so I'm going to stop trying.

You're correct that strings are used in representing the queries, but
the values that are stored and returned via the C api are strongly
dynamically typed.  BTW, I am not advocating avoiding the use of any
strings in interacting with sqlite.  That's impossible, since queries
are ultimately presented to the sqlite engine as text (possibly with
additional explicit values).  But in lisp, identifiers and keywords
are just values, too.  I don't think "? ? table values ( 1.0, 'Foo' )"
can be supplied with 'insert and 'into as parameters.

> Are we sure that a database is more efficient than a hash-table (which
> can already be printed and read)?  Or are we talking about unusually
> extreme values, like in your other message where you were loading 2000+
> packages?

Who determines what is extreme?  Tasks that aren't done today because
they are difficult to code efficiently?  Tasks that seem extreme when
you write the code in direct style may become much less extreme once a
well-crafted table/query facility is available.  I don't think simply
*installing* 2000+ packages is all that extreme in itself.  Even
loading all those packages, particularly when using redumping, is not
particularly extreme in terms of resource consumption on modern
desktop hardware.

Hash tables only index a single key of a data set.  And they don't
address tasks like efficiently joining tables.

My personal interests run to using relational programming for problems
like abstract interpretation and compiler implementation.  I'm sure
there are many applications for problems Emacs is used to solve, e.g.
tracking cross-references, tag tables, etc.

>
> > I'm sure there's more, but we won't know until the programming idiom
> > is readily available and easy to use.
>
> Are there any other languages that support this kind of interaction,
> where we could learn some lessons about the advantages and limits of
> these ideas?

You might consider the LINQ sublanguage of C# and other .NET-based
languages as an example of a useful query DSL.


Lynn