Reason behind semicolumns (i.e. "inline comments") in system output?

"Jan J. via Sbcl-help" <[email protected]>
Newsgroups gmane.lisp.steel-bank.general
Message-ID <NffiNIkTR--krHzo44rwNXAUWQpwbhab5s1VMeUPHyE7sfIomJ80xze4viGRK79KSSZYNrfQn-9z080r47W_I05Ck0umN_asIHrOuXY3fts=@protonmail.com>
Is there any particular reason as to why some REPL output has semicolumns prefixing it, as though it is trying to comment it out?

Example (SLIME):

- CL-USER> (error 123)
; Evaluation aborted on #<TYPE-ERROR expected-type:
; (OR STRING FUNCTION SYMBOL CONDITION SB-PCL::CONDITION-CLASS)
; datum: 123>.
CL-USER>
; No valueCL-USER>

I always assumed it was just a way for the implementation to differentiate between its own "system" messages, and the rest of the Lisp messages.

I am curious about the source/history of this convention.

_______________________________________________
Sbcl-help mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/sbcl-help
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.