Static Patterns

Abstract

Traditional accounts of pattern matching require nontrivial patterns to be headed by a constructor, but these are not expressive enough to model the compound calculus. The static pattern calculus admits a pattern that can match an arbitrary compound, and so can model generic queries. A new class of examples is introduced, led by generic mapping that generalises mapping on lists and trees. The static pattern calculus is slightly superior to compound calculus since its notation is more compact, and its treatment of match failure is more comprehensive. Also, it supports developments in subsequent chapters.