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# Beguiling Emacs: Guile-Emacs relaunched!
Robin Templeton (they/them)

IRC: robin on libera.chat; Fediverse: [@lispwitch@octodon.social](https://octodon.social/@lispwitch); Matrix: [@terpri:matrix.org](https://matrix.to/#/@terpri:matrix.org); website: <http://terpri.org/>; mail: <mailto:robin@terpri.org>

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[The Guile-Emacs project](https://guile-emacs.org/) seeks to develop new
foundations for Emacs, building on forty years of development to prepare
the way for the next forty. Guile-Emacs brings Emacs and Guile together
by providing a new Elisp implementation based on Guile's compiler
technology, serving as the basis for a more expressive and extensible
version of Elisp. We envision Guile and Emacs being co-developed in a
sort of mutualism, with Emacs becoming the heart of a "Lisp machine for
the 21st century" and with Guile fulfilling the promised role of Lisp
from the GNU Manifesto.

Guile-Emacs is now being developed by a democratic workers cooperative,
focused on development of the project itself and related components of
the GNU system.

In this talk, I'll cover:

-   What is Guile-Emacs, in terms of its goals and general architecture?
    Why is Guile well-suited to the goals of the project?
-   How did the Guile-Emacs project begin, and what is its status today?
-   What are the immediate tasks for Guile-Emacs development, and how
    will they improve Guile-Emacs itself as well as its component
    projects?
-   How are our long-term goals for Guile-Emacs connected to the spirit of
    Emacs and the GNU Project in general? What do we envision for the
    future of GNU Emacs?
-   How can you get involved with and support this effort?

Along the way, we'll show live demos of Guile-Emacs itself and its
extensions to Emacs Lisp.

About the speaker:

Robin Templeton is a free software advocate who enjoys programming
language design and exploring system architecture. Their fascination
with Emacs and Lisp lead them to begin work on the then-hypothetical
Guile-Emacs project during their university studies. If given the
opportunity and interest, they will bless an interested listener with a
treasure trove of obscure Lisp history.

Guile-Emacs seeks to provide new foundations for Emacs, integrating
Emacs and Guile via a new Elisp implementation. We envision a
significant role for Emacs within the GNU Project, becoming a central
part of a "Lisp machine for the 21st century".


# Discussion

## Questions and answers

-   Q: About fibers: My understanding is that the problem with making Elisp concurrent is that none of the data structures (buffer, cons, vector, window etc) are concurrency-safe.  How do fibers help with this?
    -   A: Fibers do not provide thread-safety for any of the existing
        data structures.  They are useful for building things that
        don\'t use Emacs data structures, like a network client that
        reads a \"stream\".  Fibers can introduce new data structures
        that are thread-safe, like \"thread-local buffers\".
-   Q: \<ramin\> You mentnioned that Emacs is roughly 25% written in C.
    Do you have a rough idea of how much of Guile is written in C? Could
    it be an improvement to make libguile a dependency of Emacs?
    -   A: The problem is not the quantity of C, but that there is C
        involved at every single level/layer of computation in Emacs. 
        This makes it difficult to use concepts like delimited
        continuations, that can make it easy to implement Emacs concepts
        more simply.
    -   A: About guile: it\'s about 1/2 C.
-   Q: A Common Lisp implementation for Guile sounds really cool! Is there already work on this underway?
    -   A: Yes, Robin is working on it, but focuses more on research on
        how to do a polyglot lisp environnement where elisp and
        common-lisp can work together (with lisp 1 vs lisp 2 issues with
        different name spaces, package and module system interaction,
        \...). If you are interested, the guile project will work on it.
-   Q: As someone who\'s kinda new to the concept of Guile, is the
    primary goal to transpile Emacs Lisp into Guile bytecode rather than
    primarily focusing on adding support for writing code in Guile\'s
    Scheme interface in particular? 
    -   A:
-   Q: Did switching from guile 2 to 3 give any performance benefits?
    -   A: Not benchmarking stuff here yet, because guile emacs has too
        much overhead involved in conforming to Emacs.  Have not noticed
        a perceptible change.  Based on the Gabriel benchmark results,
        it might have benefited a  bit, but for Emacs we don\'t know
        yet.  Lowering the overhead is the best place to focus on to
        optimize guile-emacs.
-   Q: Do you know if the Emacs maintainers are interested in switching to Guile as the engine for Emacs Lisp?
    -   A: Previous maintainers were cautiously optimistic and
        interested. Issues might be cross-platform compatibility.
-   Q: Do you think guile-emacs will be able to use or (collaborate
    with) some of the other awesome projects around Emacs-Lisp, like the
    gypsum project presented earlier today, or Andrea Corallo\'s efforts
    to make Emacs-Lisp more suitable for native compilation? Or even
    something like the renewed PreScheme efforts?
    -   A: Gypsum has a different focus. Guile tries to improve lisp
        instead of replacing lisp in any way. But some code can be
        shared, especially if some parts of emacs are rewritten in lisp
    -   A: For libgccjit: it is accelerating the interpreter, which is
        not great in the first place. So no direct relationship.
    -   A: For prescheme: it  is a useful tool to look at, making it
        easier to upstream one day.
-   Q: SBCL, \...You mentioned Robert Strandh\'s SICL along with SBCL---does that work help with the implementation of CL in Guile? 
    -   A: Time consuming part are the DSL from common lisp. So they can
        be used. No plan on sharing code yet, as they are open-source.
-   Q: Can you comment more on relation with hoot project and advantages
    that might bring to guile-emacs?
    -   A: Hoot is only tested on scheme decompilation. But it is a
        completely different project. One could image compile emacs to
        wasm and maybe with a different garbage collector.
-   Q:
    -   A:

## Notes

-   [https://guile-emacs.org/](https://guile-emacs.org/)
-   Some more motivation: avoid FFI to increase performance and allow
    for more optimizations (including type annotations)


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