Restarts are named jumping points established by with_restarts().
rst_list() returns the names of all restarts currently
established. rst_exists() checks if a given restart is
established. rst_jump() stops execution of the current function
and jumps to a restart point. If the restart does not exist, an
error is thrown. rst_maybe_jump() first checks that a restart
exists before jumping.
rst_list()rst_exists(.restart)
rst_jump(.restart, ...)
rst_maybe_jump(.restart, ...)
The name of a restart.
Arguments passed on to the restart function. These dots are evaluated with explicit splicing.