SLIME on Emacs with paredit in repl - how to prevent execution of incomplete but balanced expressions?

Question

I use paredit on emacs with SLIME's repl. This means that at any point during my typing on the repl, my s-expressions are balanced.

However, they may not be complete, and I might want to continue typing inside them in another line, as follows:

CL-USER> (defun print-hello ()
            )

When I start a new line by pressing the enter key, however, the SLIME repl executes my incomplete expression. I want it to wait for me to complete the expression, as follows:

CL-USER> (defun print-hello ()
            (format t "Hello, world"))

How do I make this happen please?

Also consider using the slime scratch buffer for multi line expressions, much more convenient than the real — David Hodge, Nov 14 '17 at 17:55

score 2 · Answer 1 · answered Nov 16 '17 at 07:38

For that situations, when writing long s-expressions in REPL I think that the best way is to use the slime scratch buffer. you can edit it and after that execute with

C-j

No problem pressing enter inside the buffer, I'm using sly but the capture could be like this:

(defun print-hello ()
            (format t "Hello, world"))
 ; => PRINT-HELLO

Also another alternative is working without the last parent :-(

or as suggested in a comment by @jkiisky, type the expression and add in the middle of the s expression C-j

CL-USER> (defun
)

Thanks - the last part, using C-j instead of enter when writing an expression worked for me too — Ashok Khanna, Aug 02 '21 at 12:46

score 1 · Answer 2 · answered Nov 17 '17 at 17:07

Related to your question, lispy provides integration with SLIME.

I typically never type anything into the REPL buffer. Instead, I edit all code in place in the source file, and use e to eval the current sexp.

lispy is also a super-set of paredit, if compatibility is your concern.

SLIME on Emacs with paredit in repl - how to prevent execution of incomplete but balanced expressions?

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