[slime-devel] Copying and pasting in the REPL

[Andras Simon]

On Mon, 5 Mar 2007, Robert St. Amant wrote:

> New subscriber here--I hope this isn't something that's already been
> discussed, and that it's targeted at the right mailing list.
>
> During a class I'm teaching, I typed the following into the REPL:
>
> CL-USER> (macroexpand '(prog1 1))
> (LET ((#:G74 1)) #:G74)
> T
>
> To show my students how the reader handles gensyms, I then cut and
> pasted the result above:
>
> CL-USER> (LET ((#:G74 1)) #:G74)
> 1
>
> This was unexpected.  I then tried typing the same form in, which
> gave what I expected, an error:
>
> CL-USER> (let ((#:g74 1)) #:g74)
> ;Compiler warnings :
> ;   Undeclared free variable #:G74, in an anonymous lambda form.
> ;   Unused lexical variable #:G74, in an anonymous lambda form.
> Invoking restart: Abort handling SLIME request.
> ; Evaluation aborted
>
> Am I suffering under a basic misunderstanding about what should
> happen in this situation?  It looks as if in the second expression
> above, the reader is somehow being bypassed for input that comes out
> the kill ring.

No, you're suffering from presentations :-)

Set (or customize) slime-repl-enable-presentations to nil to avoid such
mishaps.

Andras