19 Continuation Marks (BC)
A mark can be attached to the current continuation frame using
scheme_set_cont_mark. To force the creation of a new frame
(e.g., during a nested function call within your function), use
scheme_push_continuation_frame, and then remove the frame with
Add/sets a continuation mark in the current continuation.
Creates a new continuation frame. The data
record need not be
initialized, and it can be allocated on the C stack. Supply data
to remove the continuation frame.