Practical Parser Writing and Usage

Abstract

Practical parsing is concerned almost exclusively with context-free (Type 2) and regular (Type 3) grammars. Unrestricted (Type 0) and context-sensitive (Type 1) grammars are hardly used since, first, they are user-unfriendly in that it is next to impossible to construct a clear and readable Type 0 or Type 1 grammar and, second, all known parsers for them have exponential time requirements. Chapter 15 describes a number of polynomial-time and even linear-time parsers for non-Chomsky systems, but few have seen practical application. For more experimental results see (Web)Section 18.2.6.