I find that utop is very slow when I paste large programs. Is this normal, or maybe should I proceed differently ? What I do is: I write programs in my text editor (visual studio code), and then I copy and paste the parts I want to test in utop (which I opened separately in a terminal), using ctrl+…

[image] user1: I find that utop is very slow when I paste large programs. Is this normal, or maybe should I proceed differently ? There may be workarounds but it’s likely normal. Basically stdin is likely set to raw mode to be able to react to each keystroke, e.g. to perform completion. So i…

Have you tried using #use "file.ml" (see “Toplevel directives” in the OCaml manual )? Maybe the slowdown is caused by the large content in utop’s history, in which case this would help as you can #use the content of the file directly without loading it into the history.

Thanks for the suggestion. Actually, I usually test in utop my multifile project “up to a point”. Say this “point” is in the middle of my file c.ml. Then, I type in utop #mod_use "lib/a.ml";; #mod_use "lib/b.ml";; (very fast indeed) and then I copy-paste the part of c.ml from its beginning up to s…

[image] user1: I saw in the link provided by @dbuenzli that the standard REPL does not have this problem, and I may actually fall back to using $ rlwrap ocaml for these tests. Well to react to your keyboard in order to provide line edition rlwrap will also have to put stdin in raw mode, so …

Wouldn’t a #paste directive, as in ipython for instance, solve this in a simple way?

[image] dbuenzli: Well to react to your keyboard in order to provide line edition rlwrap will also have to put stdin in raw mode, so I doubt you won’t see the same problem. Actually, pasting in $ rlwrap ocaml is slightly slower than in $ ocaml, but nothing compared with $ utop.

Perhaps you could use dune utop? Dune will automatically load any given library into the REPL. Then you can explore it interactively, redefine any definitions, and so on. No need for copy-paste.

Unfortunately, it looks like dune utop <dir> can only load full directories, not individual files, and in my lib/ directory, I have files a.ml … g.ml which are correct “up to” a function somewhere in the middle of c.ml, which is why I use #mod_use on the files before c.ml, and then I manually copy-p…

In that situation I’d likely fix the compile error first, then load the library in dune utop. Another option would be to comment out all the breaking code in c.ml until the build succeeds, then load the library and go from there.

Utop very slow?

Learning

dbuenzli June 15, 2022, 3:16pm 10

You may want to have a look at the tools mentioned by @Gopiandcode and @let-def in this thread.

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Utop very slow?

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