Customizing Lisp REPLs

by nemoniac • 11 months ago

76 19 11 months ago

spauldo3• 11 months ago

That's a neat idea. But I'm curious how many people actually use native REPLs for anything beyond trivial evaluation.

I'll use a Guile or SBCL REPL for some quick math (assuming it's something that's not trivial in dc) or to test out a quick idea, but I rarely send more than one to three forms before closing it. That's only if I don't have Emacs open where I can just do it in the scratch buffer. Anything that needs more than a couple defuns goes into SLIME or guiser.

So, people who use native REPLs, what do you do with them?

nils-m-holm• 11 months ago

Loading programs, testing individual functions, examining data. I usually have two windows/consoles open: one for writing code, one for loading and testing.

spauldo3• 11 months ago

Do you do REPL customization and Readline wrapping like in the article, or are you satisfied with the basic REPL capabilities?

I think I'll give your workflow a try. I might learn something interesting from it. Worst case, I'll gain new appreciation for SLIME.

(I like your books, BTW.)

skydhash• 11 months ago

I’ve used the Node REPL to check some asumption about some library. Also the python REPL in Emacs when I was writing some logic heavy script.

lycopodiopsida• 11 months ago

If I write lisp, a REPL is always running. Used for testing functions with input and debugging.

monsieurbanana2• 11 months ago

The person you're answering is also using a REPL while coding, just not accessing it directly (= manually writing in the REPL stdin)

Instead he interacts with it via his editor's tooling, where you are in a normal file, and use a shortcut that will send a sexp/function/region/etc into the running repl and display the result.

So just to be clear you are using the repl directly?

cosmos0072• 11 months ago

So, people who use native REPLs, what do you do with them?

In my case, I use my interactive shell https://github.com/cosmos72/schemesh every day as login shell.

You can look at it as heavily customized Scheme REPL, where everything not inside parentheses is parsed and executed as shell syntax, and everything inside parentheses is parsed and executed as Scheme syntax.

Having arithmetic and procedure definition within the login shell definitely feels liberating, at least to me

cess11• 11 months ago

I've used the Picolisp REPL like that, though not as a login shell proper, but as the shell where I actually do stuff. Mainly due to the ease with which it integrates with the below shell through 'in, 'out and 'fork.

gus_massa• 11 months ago

From a few old post by Paul Graham, he used to run Hacker News in the REPL of Arc in the REPL of Racket. So it was posible to make tweaks on the moment, like changing the title to "Innocuous News" as a joke for a few hours. Also, he once changed the parent of one comment and created a cycle in the DAG and that cashed the site for a while. I can't find the article now.

Anyway, a few years ago dang changed the backend to SBCL that is more REPL friendly, so I guess this comment is showed using the REPL of Arc in the REPL of SBCL.

taeric• 11 months ago

I think this is saying different things? The question is how much of the direct interaction is with the REPL, not if a REPL is available to use.

pjmlp2• 11 months ago

Interactive development, and scripting that isn't tied to UNIX CLI culture.

But maybe I am strange, because I got to experience Smalltalk transcript, Oberon REPL, AmigaDOS and REXX, was into XEmacs when there were no UNIX based IDEs to chose from, got to use VB REPL before Microsoft killed it on VB.NET, Alegro Common Lisp, Caml Light,...

And I guess that is why nowadays I am a big Powershell fan, even if it errs on the verbosity side.

It is like having the debugger always turned on, and being able to script the OS as well.

spauldo3• 11 months ago

Sure, but do you use the native REPL for those things or do you go through SLIME or equivalent? That's what I'm curious about.

kagevf• 11 months ago

If I create an executable with SBCL's save-lisp-and-die then run that executable, it presents a repl. Not really a development scenario, but more of a "running application" scenario. But, even then, if the executable creates a swank server, I can connect to that from SLIME.

eimrine• 11 months ago

What a lovely blog!

Customizing Lisp REPLs

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