An Applicative Control-Flow Graph Based on Huet's Zipper

We are using ML to build a compiler that does low-level optimization. To support optimizations in classic imperative style, we built a control-flow graph using mutable pointers and other mutable state in the nodes. This decision proved unfortunate: the mutable flow graph was big and complex, and it led to many bugs. We have replaced it by a smaller, simpler, applicative flow graph based on Huet's (1997) zipper. The new flow graph is a success; this paper presents its design and shows how it leads to a gratifyingly simple implementation of the dataflow framework developed by Lerner, Grove, and Chambers (2002).

• Type: Journal
• Year: 2006
• Where: ENTCS
• Authors: Norman Ramsey, João Dias
• Keywords: Classic Imperative Style, ENTCS 2006, Flow Graph, Mutable Flow Graph