Time and Space Efficient Multi-method Dispatching

The dispatching problem for object oriented languages is the problem of determining the most specialized method to invoke for calls at run-time. This can be a critical component of execution performance. A number of recent results, including [Muthukrishnan and Müller SODA’96, Ferragina and Muthukrishnan ESA’96, Alstrup et al. FOCS’98], have studied this problem and in particular provided various efficient data structures for the mono-method dispatching problem. A recent paper of Ferragina, Muthukrishnan and de Berg [STOC’99] addresses the multi-method dispatching problem. Our main result is a linear space data structure for binary dispatching that supports dispatching in logarithmic time. Using the same query time as Ferragina et al., this result improves the space bound with a logarithmic factor. The IT University of Copenhagen, Glentevej 67, DK-2400 Copenhagen NV, Denmark. E-mail: fstephen,inge, [email protected]. yBRICS (Basic Research in Computer Science), Center of the Danish National Research Foundation, Department of Computer Science, University of Aarhus, Ny Munkegade, DK-8000 Århus C, Denmark. Partially supported by the IST Programme of the EU under contract number IST-1999-14186 (ALCOM-FT). E-mail: [email protected].