What makes a good REPL? • Hacker News Board

Re: What makes a good REPL?

#171

Post by Zak » Wed, Aug 30, 2017, 12:40 AM UTC

mamcx wrote: post #168

Zak wrote: post #130

Earlier quoted context omitted.

Since more than a few language implementations already do things like that, I'm inclined to say that's more or less a solved problem.

Yeah, but I have not find a resource that explain how is done.

I think is probably an RTFS sort of topic, as there may not be a manual.

Re: What makes a good REPL?

#172

Post by valw » Wed, Aug 30, 2017, 7:34 AM UTC

junke wrote: post #104

narrowtux wrote: post #74

Earlier quoted context omitted.

You could just store your modified state to new variables though

In a live-coding session, how does the existing, running code knows that it should look at the new variables instead of the old ones?

Have a look at the video. Having immutable values doesn't mean you have immutable variables / names.

Re: What makes a good REPL?

#173

Post by junke » Wed, Aug 30, 2017, 1:25 PM UTC

valw wrote: post #172

junke wrote: post #104

Earlier quoted context omitted.

In a live-coding session, how does the existing, running code knows that it should look at the new variables instead of the old ones?

Have a look at the video. Having immutable values doesn't mean you have immutable variables / names.

I know, the parent post was saying "you could just store your modified state to new variables", not replace what existing variables are bound to.

Re: What makes a good REPL?

#174

Post by mamcx » Wed, Aug 30, 2017, 5:00 PM UTC

Zak wrote: post #171

mamcx wrote: post #168

Earlier quoted context omitted.

Yeah, but I have not find a resource that explain how is done.

I think is probably an RTFS sort of topic, as there may not be a manual.

RTFS? What this mean?

Is like "some inside knowledge" but undocumented?

Re: What makes a good REPL?

#175

Post by dllthomas » Wed, Aug 30, 2017, 7:52 PM UTC

mamcx wrote: post #174

Zak wrote: post #171

Earlier quoted context omitted.

I think is probably an RTFS sort of topic, as there may not be a manual.

RTFS? What this mean? Is like "some inside knowledge" but undocumented?

"Read The [Friendly] Source [code]"

For the same concept, I prefer "UTSL"

Re: What makes a good REPL?

#176

Post by sedachv » Wed, Aug 30, 2017, 8:49 PM UTC

peatmoss wrote: post #119

gaius wrote: post #82

Saving state between runs. R has surpassed Python for me just for that feature, for interactive exploration.

I've never found a case where I've wanted to retain state between R sessions (I think doing so can be an anti-pattern). But... that image saving feature is very much like that of Common Lisp. Given Ross Ihaka's then-and-now fondness for CL, I'd be shocked if this feature weren't very much intentionally patterned off that. The original implementation of R was on top of a Scheme runtime, but I don't know if images were…

R workspaces are an idea borrowed from APL: http://aplwiki.com/LearnApl/AplWorkspace

Common Lisp and Scheme do not have any specifications for persistent state, and the implementations that do have images are all over the place in what those images do and how they are made.

Re: What makes a good REPL?

#177

Post by nerdponx » Thu, Aug 31, 2017, 12:01 AM UTC

SomeHacker44 wrote: post #149

nerdponx wrote: post #147

Earlier quoted context omitted.

> Common Lisp's REPL The SBCL and CCL REPLs do not support readline-style editing. This actually makes them infuriating to use outside of Emacs or some other IDE-like environment. There is definitely a market for a high-quality, implementation-independent Lisp REPL.

rlwrap FTW

Also linedit. But using it still requires you to add it to your favorite implementation's init file. Would it be possible to write a "meta-REPL" using linedit? Then again, there already is a Jupyter kernel for CL, so maybe I should look into making that work for me.