ABSTRACT
In implementing a marker-passing system, one is forced to address many issues. Some of these are design-level decisions involving the type of marker-passer to write. O thers involve issues th a t arise from the general process of marker-passing, rather than from any specific design. In this chapter we examine both of these types of issues and discuss some of the ramifications of each. We then discuss the actual marker-passer implemented in SCRAPS and show how it deals with both sorts of issues.
