CODEWITHSUNDEEP
emacslispslime
Omegaspard
Omegaspard

Reputation: 1960

Emacs slime management, user input and multi eval and print

I'm on ubuntu 19. Using emacs, slime and sbcl to practice some lisp.

Currently I have one buffer in slime mode in one window and the slime-description in the other window.

When I want to execute a line, I write it on the buffer and press C-c C-p.

But when I try to do the same for the line 

(defvar *name* (read))

to set the the name var with the user input, nothing is happening.

Why ?

Also I would like to execute the whole script and not one line at a time, how do I do that ?

Upvotes: 0

Views: 150

Answers (1)

user5920214
user5920214

Reputation:

'Nothing is happening' because read is waiting for you to type something at the REPL. If you look at the REPL you will be confused because the form you are evaluating is not displayed, so all you see is ... nothing, but you need to type something at it. Further, it's not clear from your description what buffers you have displayed, but I suspect the REPL is not one of them, which is going to make things even worse.

I don't know how other people use SLIME, but what I do is to have at least the REPL (the thing you get after typing M-x-slime in one window, and a file I am working on in another. You can then interact with the REPL just by typing at it, and send code to the running lisp from the file with C-M-x or any of the other commands (in particular things like C-c C-k which compiles & loads the file.

However you almost never want a file you are compiling or loading to include anything which causes read to be called at compilation or load time: the results are going to be mysterious to put it mildly: the system will just stop with no prompt waiting for you to type something. It makes much more sense to do that in the REPL:

CL-USER> (defvar *name* (read))
(here is the data I am typing in)
*NAME*

Indeed, even when you go to some lengths to make calls to read non-mysterious in files being loaded, you have to go to yet further lengths to make them safe. Consider this file, toxin.lisp:

(defvar *my-thing*
  (progn
    (format *query-io* "~&thing? ")
    (finish-output *query-io*)
    (read *query-io*)))

Now:

$ lisp
[...]
(load "toxin" :verbose t)
;Loading #P"toxin"...
thing? #.(quit)

Of course there are much worse things I could have said than that to the Lisp.

Upvotes: 1

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