Approaches to interpreter composition

• We present a viable Python/Prolog composition and show four different implementations each using a different composition style.
• We present the first experiment designed to help understand the effects of different composition styles upon performance.
• We thoroughly analyse and discuss the results of the experiment, breaking down the impact that each composition style has on performance.

In this paper, we compose six different Python and Prolog VMs into 4 pairwise compositions: one using C interpreters, one running on the JVM, one using meta-tracing interpreters, and one using a C interpreter and a meta-tracing interpreter. We show that programs that cross the language barrier frequently execute faster in a meta-tracing composition, and that meta-tracing imposes a significantly lower overhead on composed programs relative to mono-language programs.