PEPM 2017
Mon 16 - Tue 17 January 2017
co-located with POPL 2017
Tue 17 Jan 2017 16:30 - 17:00 at Salle 109, Barre 44-54 - Transformation (part II) Chair(s): Jurriaan Hage

This paper proposes FUnCAL, a functional redesign of the graph transformation language UnCAL. A large amount of graph-structured data are widely used, including biological database, XML with IDREFs, WWW, and UML diagrams in software engineering. UnCAL is a language designed for graph transformations, i.e., extracting a subpart of a graph data and converting it to a suitable form, as what XQuery does for XMLs. A distinguished feature of UnCAL is its semantics that respects bisimulation on graphs; this enables us to reason about UnCAL graph transformations as recursive functions, which is useful for reasoning as well as optimization. However, there is still a gap to apply the program-manipulation techniques studied in the programming language literature directly to UnCAL programs, due to some special features in UnCAL, especially markers. In this paper, following the observation that markers can be emulated by tuples and $\lambda$-abstractions, we transform UnCAL programs to a restricted class of usual (thus, marker-free) functional ones. By this translation, we can reason, analyze or optimize UnCAL programs as usual functional programs. Moreover, we introduce a type system for showing that a small modification to the usual lazy semantics is enough to run well-typed functional programs as finite-graph transformations in a terminating way.

#### Tue 17 Jan Times are displayed in time zone: Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna change

 16:00 - 17:00: Transformation (part II)PEPM 2017 at Salle 109, Barre 44-54 Chair(s): Jurriaan HageUtrecht University 16:00 - 16:30Talk Functional Parallels of Sequential ImperativesPEPM 2017Tiark RompfPurdue University, Kevin J. BrownStanford University 16:30 - 17:00Talk A Functional Reformulation of UnCAL Graph-Transformations: Or, Graph Transformation as Graph ReductionPEPM 2017Kazutaka Matsuda, Kazuyuki AsadaUniversity of Tokyo