[[!meta title="Gypsum: my clone of Emacs and ELisp written in Scheme"]] [[!meta copyright="Copyright © 2024 Ramin Honary"]] [[!inline pages="internal(2024/info/gypsum-nav)" raw="yes"]] # Gypsum: my clone of Emacs and ELisp written in Scheme Ramin Honary (he/him) - [[!inline pages="internal(2024/info/gypsum-before)" raw="yes"]] I would like to demonstrate an Emacs clone I have been writing in Guile Scheme for the past year, which I am tentatively calling "Gypsum". Unlike other editors which only clone the Emacs keybindings (Edwin, Jed, jEdit, Jove, Lem, MG, Yi, Zile), I hope my Emacs clone will also fully clone the Emacs Lisp programming language well enough that many of the packages in ELPA, Non-GNU ELPA, and perhaps even MELPA, can be used in "Gypsum" without any modification. I would also like to talk a little bit about the how I am implementing it (the software architecture), and invite others to contribute. I think my project is of interest to many Emacs users because, firstly, I have personally spoken with a relatively large number of people who have expressed interest in making Emacs programmable in Scheme. Secondly, there is a good amount of prior art for Scheme implementations of Emacs. There are even builds of Emacs that link to Guile which provides a "scheme-eval" built-in function that translates between Elisp data types and Scheme data types. The Guile compiler itself ships with an Emacs Lisp compiler as well, although it does not provide enough of Emacs's built-in functions to be of much use. So by using Guile, we can make use of a lot of the prior art, in fact I am currently using the tokenizer and reader used in Guile's built-in Elisp interpreter to implement "Gypsum's" Elisp interpreter. That said, I have gone out of my way to make my code fully R7RS compliant, so I hope I can port it to other Scheme implementations like MIT Scheme, Gambit, Stklos, and perhaps Chez Scheme with Gwen Weinholt's R7-to-R6RS translator. I consider the Guile version of Gypsum to be the reference implementation of what I hope will become a fully cross-platform programming language and text editor written in portable R7RS Scheme. The reference implementation of "Gypsum" is a GUI application based on Gtk using a library called "Guile-GI". Guile-GI uses the GObject Introspection framework to automatically generate Scheme language bindings to libraries like Gtk and Glib which are written in the C programming language. There is not yet any terminal-emulator version of "Gypsum." The next step of the project will be to implement enough of Elisp that we can run tests written in the Emacs Regression Testing (ERT) framework. We can then incorporate the original GNU Emacs regression test suite into Gypsum. Any new API added to Gypsum Elisp will most likely already have regression tests we can use to make sure it is working in a way that is compatible with GNU Emacs Lisp. I would like to make it as easy as possible for people to contribute to this project, and having a list of APIs to be implemented each with a set of regression tests the APIs are expected to pass, is a very good way to do that. About the speaker: My name is Ramin Honary, I have been a professional software engineer of 16 years, lately mostly doing full-stack software development. I have always been fascinated with programming languages, and especially functional languages like Lisp and Haskell. I have been using Emacs since 2017. But lately it is with Scheme that I have been spending most of my free time. I am only a Scheme programming enthusiast, I am not involved with Scheme professionally. [[!inline pages="internal(2024/info/gypsum-after)" raw="yes"]] [[!inline pages="internal(2024/info/gypsum-nav)" raw="yes"]]