Finite-state Language Processing

Book excerpt: Finite-state devices, such as finite-state automata, graphs, and finite-state transducers, have been present since the emergence of computer science and are extensively used in areas as various as program compilation, hardware modeling, and database management. Although finite-state devices have been known for some time in computational linguistics, more powerful formalisms such as context-free grammars or unification grammars have typically been preferred. Recent mathematical and algorithmic results in the field of finite-state technology have had a great impact on the representation of electronic dictionaries and on natural language processing, resulting in a new technology for language emerging out of both industrial and academic research. This book presents a discussion of fundamental finite-state algorithms, and constitutes an approach from the perspective of natural language processing.