7 ms·

I don't like REPL driven development. REPLs are celebrated as some sort of achievement in interactivity, but they're hopelessly puny, barely imitating a UNIX sh

I don't like REPL driven development. REPLs are celebrated as some sort of achievement in interactivity, but they're hopelessly puny, barely imitating a UNIX shell. When I write Emacs Lisp, I don't have a REPL. I just put point at the end of a random s-expression in a random Emacs-mode buffer, hit C-x C-e, and it gets evaluated. Or I do "eval-print-last-sexpression" to get the output on the next line. If I put my emacs in an org-mode code block, I'll get the output nicely formatted by org-mode. I can get close to this in Common Lisp with SLIME, but I've never found it as tight as Emacs Lisp. But Emacs lisp is still puny. Common Lisps had much higher aspirations than SLIME and a crappy UNIX-based Lisp executable. Allegro and Lispwerks still run on the philosophy that your IDE is just some live code in your lisp image, and you extend that image via the GUI. The same philosophy pervades (non-GNU) Smalltalk implementations. This is the sort of thing that still makes Lisp (and Smalltalk) absolutely stand out among programming languages, and it will be a crime when it is inevitably forgotten and we are left dumbfounded by the banality of REPL driven development.

mickeyp 4y ago
Emacs does have a REPL (`M-x ielm'), and it works well.
- submeta 4y ago
  Didn't know about that, although I have been using Emacs for over ten years! Tried `M-x ielm`, `(help) RET`, wow! Will explore it. Been only using the scratch buffer and `C-x C-e` to evaluate sexpressions.
  - mickeyp 4y ago
    I wrote about all the way of doing this here: https://www.masteringemacs.org/article/evaluating-elisp-emacs https://www.masteringemacs.org/article/evaluating-elisp-emac...
    - submeta 4y ago
      Ah, it's you Mickey! Got your book. Excellent! Thank you for writing it, and thank you for all the valuable stuff you put out there re learning Emacs.
lispm 4y ago
Allegro CL and LispWorks have very capable REPL experiences. They provide a mostly object-oriented implementation of Common Lisp with excellent support for the Condition system to interactively deal with errors, including hierarchical debug break loops and source level interpreters.
mikevin 4y ago
I wish GNU Emacs had better introspection, It's probably because it values user experience more but it saddens me when I see "You shouldn't use this from a lisp program, it's intended for users" or something like it. I understand the reasoning but having seen the power of introspection in Symbolics Genera makes me long for an Emacs that makes Elisp as much a feature as "Text-editing/browsing/etc". I should look into contributing I guess
st3fan 4y ago
> When I write Emacs Lisp, I don't have a REPL. I just put point at the end of a random s-expression in a random Emacs-mode buffer, hit C-x C-e, and it gets evaluated. That actually is repl driven development. It does not mean that you type everything in on a repl prompt. It means you interactively and incrementally work on a program.
- TacticalCoder 4y ago
  Yup I was going to comment basically the same: in this case Emacs itself is the REPL environment (Emacs user here).
- Jtsummers 4y ago
  Also, unless their configuration has changed things, C-x C-e will print out the results in the mini buffer at the bottom. So it retains each of the read, eval, and print parts of the read, eval, print loop. And since the program doesn't terminate (unless the expression you provided causes that), you're still in the loop part until you close emacs.
User23 4y ago
I wonder how difficult it would be to port elisp to Common Lisp and then get GNU Emacs running hosted in SBCL or whatever. I really like the idea of my editor running in the image.
- dreamcompiler 4y ago
  It's been done in the form of an Emacs clone called Hemlock. Lispworks uses it for their IDE although they don't make enough of the source available to fully customize it. Clozure Common Lisp also uses Hemlock for their IDE on the Mac and its source is all in the box. I don't think that's exactly what you asked, however, and I agree that a true Emacs running entirely on CL would be preferable.
  - math-dev 4y ago
    Source code of LW editor is mostly available. I’ve done some extensive modifications to it (implemented VIM mode), but these days I’ve moved back to Emacs- just something I prefer more
    - dreamcompiler 4y ago
      So have I but that "mostly" is my problem. Eventually I hit a wall beyond which I could not modify the editor's behavior.
  - User23 4y ago
    I believe the Nyxt project is interested in adding editing at some point. There’s also Lem which is a terminal based Emacs. GNU Emacs has by far the strongest community and ecosystem though.
- fiddlerwoaroof 4y ago
  You might be interested in: https://github.com/cxxxr/lem https://github.com/cxxxr/lem For a terminal editor, it’s impressively usable.
- math-dev 4y ago

mickeyp 4y ago

Emacs does have a REPL (`M-x ielm'), and it works well.

submeta 4y ago
Didn't know about that, although I have been using Emacs for over ten years! Tried `M-x ielm`, `(help) RET`, wow! Will explore it. Been only using the scratch buffer and `C-x C-e` to evaluate sexpressions.
- mickeyp 4y ago
  I wrote about all the way of doing this here: https://www.masteringemacs.org/article/evaluating-elisp-emacs https://www.masteringemacs.org/article/evaluating-elisp-emac...
  - submeta 4y ago
    Ah, it's you Mickey! Got your book. Excellent! Thank you for writing it, and thank you for all the valuable stuff you put out there re learning Emacs.

lispm 4y ago

Allegro CL and LispWorks have very capable REPL experiences. They provide a mostly object-oriented implementation of Common Lisp with excellent support for the Condition system to interactively deal with errors, including hierarchical debug break loops and source level interpreters.

mikevin 4y ago

I wish GNU Emacs had better introspection, It's probably because it values user experience more but it saddens me when I see "You shouldn't use this from a lisp program, it's intended for users" or something like it. I understand the reasoning but having seen the power of introspection in Symbolics Genera makes me long for an Emacs that makes Elisp as much a feature as "Text-editing/browsing/etc". I should look into contributing I guess

st3fan 4y ago

> When I write Emacs Lisp, I don't have a REPL. I just put point at the end of a random s-expression in a random Emacs-mode buffer, hit C-x C-e, and it gets evaluated. That actually is repl driven development. It does not mean that you type everything in on a repl prompt. It means you interactively and incrementally work on a program.

TacticalCoder 4y ago
Yup I was going to comment basically the same: in this case Emacs itself is the REPL environment (Emacs user here).
Jtsummers 4y ago
Also, unless their configuration has changed things, C-x C-e will print out the results in the mini buffer at the bottom. So it retains each of the read, eval, and print parts of the read, eval, print loop. And since the program doesn't terminate (unless the expression you provided causes that), you're still in the loop part until you close emacs.

User23 4y ago

I wonder how difficult it would be to port elisp to Common Lisp and then get GNU Emacs running hosted in SBCL or whatever. I really like the idea of my editor running in the image.

dreamcompiler 4y ago
It's been done in the form of an Emacs clone called Hemlock. Lispworks uses it for their IDE although they don't make enough of the source available to fully customize it. Clozure Common Lisp also uses Hemlock for their IDE on the Mac and its source is all in the box. I don't think that's exactly what you asked, however, and I agree that a true Emacs running entirely on CL would be preferable.
- math-dev 4y ago
  Source code of LW editor is mostly available. I’ve done some extensive modifications to it (implemented VIM mode), but these days I’ve moved back to Emacs- just something I prefer more
  - dreamcompiler 4y ago
    So have I but that "mostly" is my problem. Eventually I hit a wall beyond which I could not modify the editor's behavior.
- User23 4y ago
  I believe the Nyxt project is interested in adding editing at some point. There’s also Lem which is a terminal based Emacs. GNU Emacs has by far the strongest community and ecosystem though.
fiddlerwoaroof 4y ago
You might be interested in: https://github.com/cxxxr/lem https://github.com/cxxxr/lem For a terminal editor, it’s impressively usable.
math-dev 4y ago