The idea of the default continuation prompt *is* that the ordinary call/cc can be delimited earlier than at the REPL prompt (or the OS command line).
So the message is: Don't use the default continuation prompt if you don't want to interfere with the classical call/cc but want to construct something orthogonal to it. Am Mo., 9. Jan. 2023 um 12:58 Uhr schrieb Jim Rees <jimree...@gmail.com>: > > The spec implies, though does not say explicitly, that call/cc can be > implemented as follows: > > (define (call/cc f) > (call-with-non-composable-continuation f > (default-continuation-prompt-tag))) > > However, the presence of any use of call-with-continuation-prompt with the > default tag interferes with the usual expected operation of call/cc. > > So to keep people from shooting themselves in the foot and preserve the > classic behavior of call/cc, my suggestion is to specify that call/cc use a > private tag inaccessible to the user, and that in addition to the default > tag, a prompt with the call/cc-private-tag be established at the start of > every thread. >
