379 research outputs found
Strategic Rewriting
AbstractThis is a position paper preparing the round table organized during the 4th International Workshop on Reduction Strategies in Rewriting and Programming. I sketch what I believe to be important challenges of strategic rewriting
Typed Generic Traversal With Term Rewriting Strategies
A typed model of strategic term rewriting is developed. The key innovation is
that generic traversal is covered. To this end, we define a typed rewriting
calculus S'_{gamma}. The calculus employs a many-sorted type system extended by
designated generic strategy types gamma. We consider two generic strategy
types, namely the types of type-preserving and type-unifying strategies.
S'_{gamma} offers traversal combinators to construct traversals or schemes
thereof from many-sorted and generic strategies. The traversal combinators
model different forms of one-step traversal, that is, they process the
immediate subterms of a given term without anticipating any scheme of recursion
into terms. To inhabit generic types, we need to add a fundamental combinator
to lift a many-sorted strategy to a generic type gamma. This step is called
strategy extension. The semantics of the corresponding combinator states that s
is only applied if the type of the term at hand fits, otherwise the extended
strategy fails. This approach dictates that the semantics of strategy
application must be type-dependent to a certain extent. Typed strategic term
rewriting with coverage of generic term traversal is a simple but expressive
model of generic programming. It has applications in program transformation and
program analysis.Comment: 85 pages, submitted for publication to the Journal of Logic and
Algebraic Programmin
Graph Creation, Visualisation and Transformation
We describe a tool to create, edit, visualise and compute with interaction
nets - a form of graph rewriting systems. The editor, called GraphPaper, allows
users to create and edit graphs and their transformation rules using an
intuitive user interface. The editor uses the functionalities of the TULIP
system, which gives us access to a wealth of visualisation algorithms.
Interaction nets are not only a formalism for the specification of graphs, but
also a rewrite-based computation model. We discuss graph rewriting strategies
and a language to express them in order to perform strategic interaction net
rewriting
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