Polynomial Size Analysis of First-Order Shapely Functions

Autor: Ron van Kesteren, Olha Shkaravska, Marko van Eekelen
Rok vydání: 2009
Předmět:
Zdroj: Logical Methods in Computer Science, 5, 1-35
Logical Methods in Computer Science, 5, 2:10, pp. 1-35
ISSN: 1860-5974
Popis: We present a size-aware type system for first-order shapely function definitions. Here, a function definition is called shapely when the size of the result is determined exactly by a polynomial in the sizes of the arguments. Examples of shapely function definitions may be implementations of matrix multiplication and the Cartesian product of two lists. The type system is proved to be sound w.r.t. the operational semantics of the language. The type checking problem is shown to be undecidable in general. We define a natural syntactic restriction such that the type checking becomes decidable, even though size polynomials are not necessarily linear or monotonic. Furthermore, we have shown that the type-inference problem is at least semi-decidable (under this restriction). We have implemented a procedure that combines run-time testing and type-checking to automatically obtain size dependencies. It terminates on total typable function definitions.
Comment: 35 pages, 1 figure
Databáze: OpenAIRE